Home

PRECISION INSTRUMENTS & SYSTEMS

1. Front Note The electrical module is shown with its cover removed Figure 5 1 Chassis Assembly Top View 5 4 May 2000 MENSOR CORP MENSOR CORP EVCTS CALIBRATION The EVCTS automatically adjusts the pressure reading for the effects of temperature and non linearity within the calibrated temperature range of 15 45 The process is referred to as dynamic compensation because each reading is so adjusted before it is output to the display or to a communi cation bus Thus a calibrated EVCTS operated within its temperature band and with proper zero and span adjustments will provide accurate pres sure measurements The EVCTS should have the span verified peri odically on each of its transducers channels to insure their stability Initially the recommended period between calibrations is three months This period may be extended as confidence is gained in the span stability CALIBRATION ENVIRONMENT For maximum accuracy allow both channels ofthe EVCTS to warm up in the MEASURE mode for a minimum of 45 minutes in an ambient tempera ture which is in the specified calibration range and stable In addition the instrument should be at rest on a stable platform which is free of excessive vibration and shock VENT SHUT OFF PRESSURE SUPPLY LINE SHUT OFF REGULATOR VALVES METERING VALVE V
2. Kk O O O memes O Solenoid Driver Board J Figure 9 3 Electrical Module Front View CAUTION ESD PROTECTION REQUIRED The proper use of grounded work surfaces and personal wrist straps are required when coming into contact with exposed circuits printed circuit boards to prevent static discharge damage to EVCTS CMOS SETUP An AT compatible Computer Keyboard compatible monitor monochrome monitor is adequate User supplied _ Monitor Connector TT optional CN SOO di O ww eS conse la To restore the BIOS data CMOS Setup 1 Turn off power to the electrical module sensitive electronic components MENSOR CORP May 2000 APPENDIX EVCTS 2 If necessary install the video driver into an available slot on the motherboard To gain access to the interior of the electrical module refer to the text under the headings Module Replacement and Electrical Module in Section 5 Maintenance Connect the monitor to the video driver board 4 Connect the keyboard to the keyboard connector on the front of the electrical module see
3. N 9 I L OONN 10 D101 D102 D103 D104 EOI DAV NRFD NDAC IFC SRQ ATN SHIELD Connect to Earth GND D105 D106 D107 D108 REN PAIRED WITH 6 PAIRED WITH 7 PAIRED WITH 8 PAIRED WITH 9 PAIRED WITH 10 PAIRED WITH 11 GND PINS 19 21 AND 23 ARE PART OF TWISTED PAIRS WITH OPPOSING PINS TO BE GROUNDED NEAR TERMINATION OF OTHER WIRE Figure 9 2 IEEE Connector and Pin Functions 9 6 May 2000 MENSOR CORP APPENDIX Before proceeding with the CMOS Setup routine determine the condition of the CMOS backup battery on the CPU Board If it is not fresh and viable or if it is suspect replace it In order to proceed with this routine the following additional equipment is required 2 Most electrical modules come with a combination video driver printer driver card capable of running a Hercules type monochrome graphics monitor If this is the case there will be an unoccupied 9 pin D sub female connector available on the front of the electrical module see figure 9 2 Otherwise it is necessary for the user to provide a video driver and CAUTION DO NOT CONNECT A MONITOR TO THE 9 PIN D SUB CONNECTOR ON THE SOLENOID DRIVER BOARD THAT HAS THE SOLENOID DRIVER LINES PLUGGED INTO IT DOING SO COULD SEVERELY DAMAGE THE MONITOR 3 A graphics monitor compatible with the above video driver card A Hercules compatible Factory supplied Monitor Connector some units
4. QHOMSSVd x NVdS LAS Sd OHu3Z LAS AV 1dSIG IN3A INOS T vas Sido 905 ora sar wo 54 3 Je GJ Oa G G GO C G HO 9 Menu Tree Figure 3 2 EVCTS Menu Tree MENSOR CORP May 2000 3 6 MENSOR EVCTS REMOTE OPERATION The Engine Vane Control Test System EVCTS may be operated from a remote computer using the 488 GPIB communication protocol The host computer must contain an IEEE 488 Commu nications Board 488 The manufacturer of host IEEE 488 interface board provides software to allow communication between the board and various programming lan guages An interactive program for debugging is usually provided as well Refer to the board manu facturer s documentation for more information EVCTS IEEE 488 Capability Codes E Full source handshake capability ees Full acceptor handshake capability Talker with serial poll and unaddress if MLA L4 S e s Listener with unaddress if MTA SRI zu Full service request capability RL1 Full remote local capability including LLO ea rs No parallel poll capability Full device clear capability Full device trigger capability ane O eR cs No controller capability Tri state outputs The EVCTS also contains many features of IEEE 488 2 the latest version of this protocol EVCTS responds to the following IEEE 488
5. 1 7 2 INSTALLATION RP rrr 2 1 Pressure Connections 2 1 SUPPEY PressSure POLL zs A AS ATL 2 1 EXHAUST Pressure Ports 2 1 MEASURE CONTROL Pressure Ports 2 1 ca x 2A bun ee ae e zc Sen ee ge Cause 2 1 3 LOCAL OPERATION 5ystem OVervieW i A A es 3 1 Keypad te ici Set Ke cea adn xi ede bxc AS A 3 1 Functions s eon dala OA hee Roy as 3 1 Dual Passwords 222585 de A s 3 4 Keypad Functions List 3 4 Menu Descriptions Ye x me a CS Nou vnu y VE ems 3 5 Men Tree e g 425 5 gt cats cee diran eo kake eG hg Ae ep ele ae 3 6 4 REMOTE OPERATION IEEE 488 205 ue gee SEU o RR ae a Po el do tirr By eae AT DRE NU da 4 1 Command and Query Format 4 1 Command Formati do Saya AA deu c UTR 4 1 Query Format e ec at ee ole dm md 4 1 subsystem Fjeld J 2 4 4 25 A AA brut 4 2 Command Query Field 4 2 Command Query Field A khe ler sy d ah Qe Sl er a 4 2 Data Field AD A zy Renfe Be A 4 2 Command Query Reference 4 3 MEN
6. F10 Save amp Exit Figure 9 4 BIOS Setup Opening Screen 9 8 May 2000 MENSOR CORP EVCTS APPENDIX BIOS SETUP PROGRAM STANDARD CMOS SETUP C 1992 American Megatrends Inc All Rights Reserved mn date year Mon Nov 30 1992 Base memory 640 KB hour min sec 12 47 22 Ext memory 0 KB Cyln Head Wpcom LZone Sect Size Hard disk C type talled Hard disk D type talled Floppy Drive A iod 3 1 2 Floppy Drive B talled Primary Display 5 talled Keyboard 11 Month Jan Feb Dec Date 2 101 02 03 2 31 Year 1901 1902 2099 ESC Exit Pe y b Select F2 F3 Color Pu Pd Modify Figure 9 5 Standard CMOS Setup Screen BIOS SETUP PROGRAM ADVANCED CMOS SETUP C 1992 American Megatrends Inc All Rights Reserved Above 1 MB Memory Disabled Hard Disk Type 47 RAM Area 0 300 Numeric Processor Test Enabled Floppy Drive Seek At Boot Enabled System Boot Up Sequence s AL Fast Gate A20 Option Enabled Password Checking Option Setup Video ROM Shadow C000 32K Enabled System ROM Shadow F000 64K Enabled Fast reset Enabled Cyrix cache Disabled ATBUS Stepping Enabled Write wait state OW 2CLK2 ESC Exit lt y 5 1 Ctrl Pu Pd Modify Fl Help F2 F3 Color F5 O1d Values F6 BIOS Setup
7. Table 5 1 Spare Parts Part Description Part Number Miscellaneous Manual 0014736001 Fuses 4100111150 Power Cord 4000400002 Rubber Feet 3201300001 Front Panel Assembly 0014181001 Display Module 5000400012 Electrical Module 0014812001 Multi Board 4904000029 GPIB Board 4904000015 Solenoid Driver Board 0014813001 Modified PLA Board for Pt3 or 0014293001 Ps3 Floppy Drive 4907000002 Power Supply modified 0014168001 CMOS Backup Battery 6 V 4100400015 Pneumatics LP Regulator Top Cap Assem 0014266002 bly Std Fitting Adapter 7 16 20 to 6000602015 1 8 NPT Female Fitting Adapter 7 16 20 to 6000604001 1 4 NPT Female O ring seals for 7 16 20 Fitting 4250010020 MENSOR CORP May 2000 EVCTS Rear 1 0 GPIB SOLENOID DRIVER PLA SOLENOID DRIVER PLA SN O gt or O
8. or Ps3 AP3 according to gt symbol F2 Pt3 AP3 normal or Pt3 Ps3 alternate display Not Used CAL ZERO Set zero on selected channel SPAN Set span on selected channel PASSWORDS Change Zero or Master Password TEST EXHAUST Test exhaust SUPPLY Test supply SENSOR Test sensor CONTROL VALVES Test regulator valves PNEUMATICS Test pneumatic valves LIMITS CONTROL RATE MODE Set RATE to Slow Medium or FAST MEASURE FILTER Set filter to Low NORMAL or High SYSTEM DEFAULTS Sets system parameters to default values HELP Shows instrument name serial number and software version METRIC Change pressure units to MBAR MMHG or KPA ENGLISH Change pressure units to INHG or PSI GPIB Change address SERIAL Disabled STBY Set system to STANDBY mode MEAS Set system to MEASURE mode CONT Set system to CONTROL mode VENT Set system to VENT mode MENSORO 2000 EVCTS LOCAL OPERATION GSYINDIY quoMsSvd H31SVN gt IVNOILAO QHOMSSVd OYZZ AHIN3 31003X3 4315 3NO QV3HV 110805 931 110895 AHIN3 HV310 G3 X NOISH3A n N3 IN 195 1531 3NVA 3NISN3 JOSUDUJ S3dON AHVWIHd mma o AA L SLId 4015 OLLVINNINA 8 S3ATVA L 7TOHINOO s a VIVA Vd 1INVI30 HOSN3S 00261 15 0096 SHINN uaria 00 2 0021 200 anva ssauaav DHNI Yvan 300N 3Lv4 l1SnVHX3 2 80FOW 86 s OIH LHIN SLINN 8 4 1NOO SVAW 915
9. 0C 22 kilopascals KPA MATERIALS IN CONTACT WITH PRESSURE MEDIUM The recommended pressure medium is clean dry non corrosive gases Consult Mensor Corporation for applications requiring liquid filled pressure sensors Table 9 5 Materials in Contact with Pressure Medium Chamber Gauge Unit Pressure Reference Absolute Units Pressure N A Metallics Aluminum X X Brass X X Copper X Gold X Solder 60 40 X Stainless Steel X X 300 Series Non Metallics Buna N Rubber X X Silicon X Loctite Sealant X X PVC X Silicone Grease X X Silicone Rubber X Teflon X Fluorocarbon X X 9 4 May 2000 MENSOR CORP EVCTS APPENDIX HEAD PRESSURE CORRECTION The accuracy of pressure measurement depends on several factors one of which is the consideration of the head pressure in the system The pressure medium whether a gas or liquid can cause an error in the measurement if not considered In some cases the offset may be insignificant and it may be ignored The following information provides instructions for determining the density of the pressure medium and how to calculate the head pressure effect Gas Density Liquids and gases have mass and are affected by gravity The extent of the effect is dependent upon the density of the pressure medium Liquids normally have a constant density that does not change with pressure Gases howev
10. SDC Selected Device Clear A command used to reset the internal functions of an addressed listener Serial Poll The process of polling and reading the status of one specified device on the bus Span The algebraic difference between the lower and upper limits of the range See also Full Scale and Span SRQ Service Request A GPIB line that a device asserts to notify the controller that the device needs service Stability The ability of an instrument to retain its perform ance characteristics for an extended period of time May 2000 EVCTS Status Byte The data byte sent by a device when it is serially polled Talker A GPIB device that sends device dependent mes sages to listeners Temperature Error The maximum change in output at any pressure value within the specified range when the transducer temperature is changed from the nomi nal compensated temperature mid range of the stated compensated temperature range to the compensated temperature extremes Temperature Range Compensated The temperature range over which the instrument specifications are specified Temperature Range Operating The range of ambient temperatures within which the instrument will function and not suffer any damage or permanent change in characteristics Uncertainty The maximum credible limits for the difference between the true value and the measured value of the pressure under consideration Vacuum Pressure A pressure les
11. 2 6 2 ug atin a RA 2 1 CMOS Memory Battery Replacement 5 2 CMOS Read Only 5 2 CMOS Setup 9 7 Command and Query Format 4 1 Command Query Field 4 2 Communications 7 2 Compensation 6 1 Connections Pressure 2 1 Connector s 2h Logo Lo 2 on 3 oh R3 Een 3 o2 1 7 IEEE 2 aoo d e enfe 9 6 Control Bi Directional Pressure 8 1 Minimum Pressure 7 3 Stability 7 3 Conversion Factors Pressure 9 2 Cord 1 1 vcn A Ta Sed eter 7 2 Damage 1 1 Mlr AS 4 2 Density Gas O AS s 9 5 Dimensional Outline 7 1 Disk 1 3 1 6 Disk Program Information 1 3 Replacem nt osa eG Roy 9 meu ea 5 1 DiSpl y 2 oos Weck DIEN A 1 2 7 2 Drift uo mo ROSEO Fou YS KS 7 2 2000 INDEX Span e 4 7 2 ZETO uh b e Q al deos ep gone de n WA dy 7 2 Dynamic Compensation 6 1 Dynamic 7 3 Electrical Block Diagram 1 3 Electrical Module 1 3 1 6 9 7 Replacement eii d
12. 2000 MENSOR CORP EVCTS TABLE OF CONTENTS TABLE OF CONTENTS Warranty is Et Rio ii Warnings and Caution K KE KEKE K K KEK K K KE KEK K KK K KK KK KK iii Please Notice s av e kera ad uv NN iii Packaging for Shipment 4 ll a iv Trademarks x Lak Reach eR A iv Software License iv Mensor Background 2 2 2 1 INTRODUCTION Did you get Everything s p a a 2 2 2 1 1 Initial Inspection 1 1 Meet your 5 Sup rune UP 2 ya R dL 1 1 Mstrument Case y s a lt 45 4 amp 4 Des M Q BARI 0 30 04 Q ae 1 2 Front Panel s sie en amp AR e RU US Soe ae amp Bk Seres c UE HIE 1 2 Rear Panel 4 kl WQ A ea Eh a 1 2 Electrical Mod le cea rd amp n QE WIE uU RU LI RUN A REA 1 3 Pneumatic Module koe 44 2 2 r dk ec See 85 80 da 1 4 Chassis Assembly 9 gt ede e eue Sea OE a de N jer SS 1 6 Power Up A eee ue Cm Dae dec iR CR 1 7 H y u Have Problems 4 2 49 Qi jn e ek Xue RI XU Ud Ed 1 7 Calibration Services 3 e uL D der
13. May 2000 7 1 SPECIFICATIONS Display Vacuum fluorescent 2 lines of 40 characters Keypad 15 dual function keys and one shift 2nd key Power Standard 115 vac 60 Hz 125 VA typical 90 132 or 180 264 vac 47 463 Hz 175 VA max Operating Environment Temperature 0 to 50 Note This is not the compensated temperature range Humidity 5 to 95 RH non condensing hu midity Shipping Storage And Handling Environ ment 20 to 70 Minimal vibration 5 gravities acceleration maximum Non condensing humidity Gravity Orientation Effect Negligible effect on span linearity and zero in any attitude Mechanical Shock 5 gravities maximum Pressure Medium Clean dry non corrosive gases See the table Materials in Contact with Pressure Medium in the Appendix Filters Internal replaceable 20 micron filters are in line with all rear panel ports CPU 80386 or higher Communications IEEE 488 1 and IEEE 488 2 Fittings 7 16 20 SAE MS female 1 8 Female NPT adapters provided 7 2 2000 EVCTS Mounting Standard Table model Optional Rack Mount Kit with slides is avail able for mounting in 19 inch rack Pressure maximum 200 inHga atmosphere to any port MEASUREMENT SPECIFICATIONS Accuracy Pt3 0 01 inHga Ps3 0 01 inHga Resolution Pt3 0 001 inHga Ps3 0 001 inHga Response Time 33 milliseconds Warm up Approximately 45 minutes to achieve full accu ra
14. iv May 2000 MENSOR CORP EVCTS PREFACE MENSOR BACKGROUND HISTORY Mensor was established in 1969 in Houston Texas as an independent spin off from the Texas Instruments TI Pressure Instrument Group As a private corporation Mensor s objective was to design and produce high accuracy high quality easy to use pressure instru ments In 1978 Mensor moved to its present location in San Marcos on Interstate 35 the Austin San Antonio corridor Two and a half years after the move the plant was destroyed by fire on Friday February 13 1981 Mensor resolved to come back and almost before the ashes had cooled construction of a new building began on the same site Six months after the disaster Mensor moved into its present facility and began shipping products to customers who had waited patiently for the recovery PEOPLE The key to Mensor s strength in the marketplace is the concentration of experienced people in the field of precision pressure measurement and control The company s founders previously worked in various capacities in the Pressure Instrument Group of Texas Instruments including engineering production and marketing These founders were involved in the design of the original quartz bourdon pressure gauge at TI Mensor s CEO Jerry Fruit is co holder of the patent on using a fused quartz bourdon tube to accurately measure pressure The 50 current full time Mensor employees have an average longevity of fourteen years That s a lo
15. per minute recommended One pump per chan nel recommended Reference Pressure Permanent vacuum Stability of Controlled Pressure Pt3 0 004 inHga Ps3 0 004 inHga Minimum Controlled Pressure 0 1 inHga MENSOR CORP Dynamic Response slew time for Fast Re sponse mode 160 seconds maximum between any two pres sure points from 0 5 FS above the EXHAUST pressure to FS to within 0 1 FS of the set point into a 1 2 liter volume A larger volume will lengthen the stated time Settling Time 15 seconds after the slew time as indicated above for pressure to remain within 0 01 FS of the set control point External volume will lengthen the stated time Overshoot Pt3 0 01 inHga Ps3 0 01 inHga May 2000 SPECIFICATIONS EVCTS User s Notes 7 4 May 2000 MENSOR CORP EVCTS OPTIONS This section lists options available for the EVCTS Users might consider letting the factory install a special feature not listed here Mensor welcomes the opportunity to quote on such requests The cost of adding an enhancement frequently will amortize itself in a very short time because of improved process efficiency RELIEF VALVES There are several types of relief valves available One way differential Two way differential One way absolute One way absolute with vacuum gauge tube Relief valves are available for pressure ranges from 0 5 psi to 1020 psi Over time contaminants in the system ma
16. 2 Front Panel ea oe a Se ah ee 1 2 TiS Rear Panel a to Qa S Q SNP yda ah ls ep yg Ga ay a 1 2 1 4 Internal Electrical Module Top View 1 3 1 5 Electrical Block Diagram s t KK 1 3 1 6 Pneumatic Module Top View 1 4 1 7 Pneumatic Schematic 22224522924 anak Za nk wo ME RR RU 1 5 1 8 Chassis Assembly Top View 1 6 9 I Keypad A o A deha 3 1 3 2 EVCTS Menu Tree u cay QU WL n 363015601 3 6 5 1 Chassis Assembly Top View 5 4 6 1 Calibration 6 1 7 l DimensionalOutline 7 1 S l Transport Case x 2R A A Ge ee A 8 1 8 2 Rack Mount Dimensions 8 2 8 3 Rack 8 3 8 4 Slide 8 3 9 1 Head Pressure Calculation 9 5 9 2 IEEE Connector And Pin Functions 9 6 9 3 Electrical Module Front VieW s t r s K KE K K K s t t s 9 7 9 4 BIOS Setup Operating Screen 9 8 9 5 Standard Cmos Setup Sc
17. 75 4 45 cm RECOMMENDED INSIDE THE RACK ABOVE AND BELOW THE EVCTS FOR VENTILATION COUNTERSINK 4 HOLES ON 1 ERR AEAN PEAL BERD 7 17 78 6 31 32 17 70 VERTICAL MOUNTING RAILS 5 8 1 59 cm VERTICAL SLIDE LOCATION 2 5 08 cm Figure 8 3 Rack Specifications THREADED RETAINING PLATE RACK REAR VERTICAL RACK FRONT VERTICAL 10 32 x 1 2 10 32 X 1 2 PAN HEAD PAN HEAD 2 PLACES 10 32 X 1 2 2 PER SLIDE ji FLAT HEAD 35315 2 PER SLIDE SLIDE MEMBER med PIN ON INNER MATES WITH MEMBER SIDE MUST ATTACHED TO EPRTS BE DOWN lt SLIDE DEPTH 22 TO 25 55 88 TO 63 50 cm WITH BRACKET PROVIDED Figure 8 4 Slide Specifications MENSOR CORP May 2000 8 3 OPTIONS EVCTS User s Notes 8 4 May 2000 MENSOR CORP EVCTS APPENDIX APPENDIX TABLE OF CONTENTS Conversion Factors 9 2 Conversion Factors Psi Table 9 1 9 2 Conversion Factors Millitorr Table 92 9 2 Temperature Conversion Table 9 3 9 3 Measurement Units Table 9 4 9 4 Materials in Contact with Pressure Medium Table 9 5 9 4 Head Pressure Correction Gas Density Table 9 6 U a AWA 2 A a 9 5 Head Pressure Calculation Figure
18. 8 3 Output Format for Measurement Units 9 4 Overshoot ama a Say 6 PACES 7 3 Packaging for iv Panel O 3 4 A AS 1 2 e e O 1 2 3 4 Plumbing s s s t eana s s 2 1 Pneumatic Module 1 1 1 4 1 6 Replacement lt s eoe Boxe chos a 5 1 Pneumatic Schematic 1 5 2 1 Pneumatic Volume 7 2 Ports Communication 2 1 2 iD dicU C MEME send 2 1 Measure Control K K K 2 1 PresSSure j c Ad oes Qa PARA dod 1 2 2 1 1 7 Supply s Aa 2 1 POWER suos esa G kash 1 7 2 1 7 2 A 1 1 RIA Pe adea mee s 2 1 May 2000 Power Supply 1 3 PowerlJpl n lek ee haa ehe 1 7 Pressure Connections 22502 nus ues 2 1 Control Pressure Check 2 1 Controlled Stability 7 3 Conversion sys so pa o a A Ges e Pv pP li 9 2 Exhausts A E IET 7 3 7 2 9 4 Minimum Controlled 7 3 POTIS LR A A AA raf 1 2 2 1 R nges 3 os A ded ed hg 4 7 3 Rate osa a da 7 3 Reference P05 a kie Bas Pe J 7 3 SOUICe 2204 a foe A dr A div ee DEYA 7 3 i o AR 9 2 Pressure Medium Materials in Co
19. 80 2 78 37 98 60 30 56 87 188 60 58 33 137 278 60 86 11 187 368 60 3 33 38 100 40 31 11 88 190 40 58 89 138 280 40 86 67 188 370 40 3 89 39 102 20 31 67 89 192 20 59 44 139 282 20 87 22 189 372 20 4 44 40 104 00 32 22 90 194 00 60 00 140 284 00 87 78 190 374 00 5 00 41 105 80 32 78 91 295 80 60 56 141 285 80 88 33 191 375 80 5 56 42 107 60 33 33 92 197 60 61 11 142 287 60 88 89 192 377 60 6 11 43 109 40 33 89 93 199 40 61 67 143 289 40 89 44 193 379 40 6 67 44 111 20 34 44 94 201 20 62 22 144 291 20 90 00 194 381 20 7 22 45 113 00 35 00 95 203 00 62 78 145 293 00 90 56 195 383 00 7 78 46 114 80 35 56 96 204 80 63 33 146 294 80 91 11 196 384 80 8 33 47 116 60 36 11 97 206 60 63 89 147 296 60 91 67 197 386 60 8 89 48 118 40 36 67 98 208 40 64 44 148 298 40 92 22 198 388 40 9 44 49 120 20 37 22 99 210 20 65 00 149 300 20 92 78 199 390 20 MENSOR 2000 9 3 APPENDIX EVCTS MEASUREMENT UNITS Number The unitno command selects the measurement units to be output on the bus and the display The syntax for the unitno command is UNITS N where N is a number from the Units column in the following table Table 9 4 Measurement Units Number Units Output Format 1 pounds per square inch PSI 2 inches of mercury 0 0 15 millibar MBAR 19 millimeters of mercury 0 C MMHG
20. 9 11 9 5 IEEE Connector and Pin Functions Figure 9 2 9 6 EMOS SETUP ae a Roe A a ares 9 7 Electrical Module Front View Figure 9 3 9 7 BIOS Setup Opening Screen Figure 9 4 9 8 Standard CMOS Setup Screen Figure 9 5 9 9 Advanced CMOS Setup Screen Figure 9 6 9 9 Commands Queries And Default Values Table 9 7 9 10 MENSOR CORP May 2000 9 1 APPENDIX EVCTS CONVERSION FACTORS PRESSURE Table 9 1 Conversion Factors psi Units Pressure Unit To convert from Psi To convert to Psi 1 PSI 1 1 2 INHG 0C 2 036020 0 4911544 15 MBAR 68 94757 0 01450377 19 MMHG 0C 51 71508 0 01933672 22 KPA 6 894757 0 1450377 Table 9 2 Conversion Factors millitorr Units Pressure Unit To Convert From Millitorr To Convert To Millitorr 1 PSI 0 0000193367 51715 1 2 INHG 0C 0 0000393701 25400 0 15 MBAR 0 00133322 750 064 19 MMHG 0C 0 001 1000 00 22 KPA 0 000133322 7500 64 9 2 May 2000 MENSOR CORP EVCTS TEMPERATURE CONVERSION Table 9 3 Temperature Conversion APPENDIX Find the known value in a center shaded column If the known value is then the equivalent value is found in the F column or if the known value is in F then the
21. Changes the mode to MEASURE Change mode to CONTROL 2nd CONT Changes the mode to CONTROL Change mode to VENT 2nd VENT Changes the mode to VENT Select METRIC units 2nd METRIC then or to select the desired units Changes the pressure units of both channels simultaneously Select ENGLISH units 2nd ENG then or to select the desired units Changes the pressure units of both channels simultaneously Change GPIB address 2nd GPIB and number keys to enter address then press Changes the GPIB address of the instrument to the number entered Set transducer ZERO 2nd CAL Password may be Sets the zero of the channel required then number keys to enter selected by 2nd F1 desired zero reading then Set transducer SPAN 2nd CAL Password is required Sets the span of the channel then number keys to enter desired span reading then selected by 2nd F1 Available only in NORMAL AP3 mode May 2000 MENSOR CORP EVCTS Menu Descriptions The following table gives a brief description of the functions provided under each of the menu keys Items shown in bold face type are default values LOCAL OPERATION Table 3 2 Description of Menu Key Functions Menu Sub Menu Function F1 Select channel to edit
22. DRIVER SOLENOID DRIVER PLA PLA n m 5 2 2 m 2 0 DBS N o 1 6 Note The electrical module is shown with its cover removed Front Figure 1 8 Chassis Assembly Top View May 2000 MENSOR CORP MENSOR EVCTS POWER UP You can confirm that your EVCTS is operational right now Simply apply power to the power con nector on the rear of the instrument remove any plastic plugs from the rear panel pressure ports and turn the power switch ON The system will go through a brief initialization process and then the display should appear similar to the following illus tration IHHG On the left half of the display the gt symbol on the top line indicates that Pt3 is the active channel and this is followed by standard atmospheric pressure Displayed directly under these are the current op erating mode default at power up is VENT and the local atmospheric pressure as measured by the Pt3 transducer The right half of
23. be equal to or greater than 50 of the transducer range or the system will not accept the entry The range of span adjustment available is 10 of the transducer full scale value From the keypad push 2nd CAL enter password At the SENSOR SPAN prompt type in the true pressure and then to enter the reading The display should now indicate the new true pressure for each channel Press 2nd F1 to toggle to the alternate channel and check that the shut off valve is in the proper state as described above Set the applied known pressure equal to or near the full scale value for this sensor Type in the true pres sure and Both channels are now spanned to the new values Press CE two times to back out of the calibration functions To set span over the GPIB send the command Channel SPAN value where channel is Pt3 or Ps3 and value is the true pressure applied to the sen sor The recalibration is now complete An alternate to entering a new span value while in LOCAL mode is to just press at the 2 prompt This will remove the current span value and re es tablish the factory entered span value for the active channel The same thing can be accomplished in REMOTE mode by sending NEL space ZERO space over the bus for each channel MENSOR CORP EVCTS SPECIFICATIONS SPECIFICATIONS Accuracy specifications presented herein are ob GENERAL SPECIFICATIONS tained by comp
24. conversion is found in the column G F eC F G F 17 78 0 32 00 10 00 50 122 00 37 78 100 212 00 65 56 150 302 00 17 22 33 80 10 56 51 123 80 38 33 101 213 80 66 11 151 303 80 16 67 2 35 60 11 11 52 1125 60 38 89 102 215 60 66 67 152 305 60 16 11 3 00 11 67 53 127 40 39 44 103 217 40 67 22 153 307 40 15 56 4 39 20 12 22 129 20 40 00 1104 219 20 67 78 154 309 20 15 00 5 41 00 12 78 55 131 00 40 56 105 221 00 68 33 155 311 00 14 44 6 42 80 13 331 56 132 80 41 11 106 222 80 68 89 156 312 80 13 89 7 44 60 13 89 57 134 60 41 67 107 224 60 69 44 157 314 60 13 33 8 46 40 14 44 58 136 40 42 22 108 226 40 70 00 1158 316 40 12 78 9 48 20 15 00 59 138 20 42 78 109 228 20 70 56 159 318 20 12 22 10 50 00 15 56 60 140 00 43 33 110 230 00 71 11 160 320 00 11 67 51 80 16 11 61 141 80 43 89 111 231 80 71 67 161 321 80 11 11 12 53 60 16 67 62 143 60 44 44 112 233 60 72 22 1162 323 60 10 56 13 55 40 17 22 63 145 40 45 00 113 235 40 72 78 1163 325 40 10 00 14 57 20 17 78 64 147 20 45 56 114 237 20 73 33 164 327 20 9 44 15 59 00 18 33 65 149 00 46 11 1
25. ing in the display CONTROL RATE MODE This sub menu will display the current RATE status as either slow medium or fast by a closed circle indicator The fast rate causes the controller output to slew at maximum speed from its current setting to a newly commanded setpoint Press or to step through the choices and to en able the highlighted choice MENSOR CORP EVCTS HELP MEASURE FILTER Allows the amount of filtering applied to the output reading to be selected for optimum performance The available choices presented are Low Normal or High which represent 50 90 and 99 filter rates respectively The low filter rate is closest to real time pressure readings but this can be noisy in the display A more stable display of the numbers is obtained with Normal or High The display indicates the current choice with a filled circle Step through to the desired value with the or key then press to enable the highlighted choice SYSTEM DEFAULTS With SYSTEM DEFAULTS showing in the display press to restore all default values to their factory settings Which values are the factory default settings are identified in Menu Descriptions listed in this section The only display available from the HELP menu shows the instrument name its serial number and the software version number currently loaded into the system METRIC Entering the METRIC menu brings up ENG GPIB SERIAL STBY MENS
26. interface functions SRQ Service Request The EVCTS asserts service request when ever an error is encountered When the bus controller issues a serial poll the error will be cleared If automatic serial polling is available with your IEEE 488 board turn this feature off if you do not want to ignore errors see ERROR command LLO Local Lockout The front panel keyboard of the EVCTS may be locked by sending LLO or the command LOCK ON GET Group Execute Trigger When this message is received the EVCTS will save the current readings until the next time it is addressed as a talker REMOTE OPERATION GTL Go To Local When this message is received the EVCTS will return to local operation and unlock the keyboard DCL Device Clear When this message is received the EVCTS will clear all errors and buffers and remain in the REMOTE mode SDC Selected Device Clear Responds as DCL EOI End or Identify May be used to terminate a command or query in the place of or concurrent with the transmission of the terminating linefeed Command and Query Format All commands messages sent to the EVCTS and queries requests for messages from the EVCTS follow a common format The EVCTS accepts com mands and queries in the form of ASCII strings The strings are divided into two or three fields strings must terminate with a linefeed lt gt hex 10 dec fields must be separated with at least one whitespace character 20 he
27. manner performed without specific factory permission voids this warranty MENSOR CORPORATION MAKES NO WARRANTY OF ANY KIND WITH REGARD TO THIS MANUAL INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE Mensor Corporation shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing performance or use of this material EVCTS May 2000 MENSOR CORP EVCTS PREFACE WARNINGS AND CAUTION NOTES WARNING NOT EXPLOSION PROOF Installation of this instrument in an area requiring devices rated as intrinsically safe is not recommended WARNING POSSIBLE INJURY The tubing valves and other apparatus attached to the gauge must be adequate for the maximum pressure which will be applied otherwise physical injury to the operator or bystanders is possible CAUTION USE THE PROPER PRESSURE MEDIUM USE ONLY CLEAN DRY NON CORROSIVE GASES THIS INSTRUMENT IS NOT DESIGNED FOR OXYGEN USE ATTENTION STATIC SENSITIVE DEVICES HANDLING PRECAUTIONS REQUIRED CAUTION The proper use of grounded work surfaces and personnel are required when coming into contact with printed circuit boards in order to prevent static discharge damage to sensitive electronic components PLEASE NOTICE The product specifications and other information contained in this manual are subject to change without notice Mensor Corporation has ma
28. of time Air speed is related to the free stream total pressure ram air pressure and the static or barometric pressure Altitude The vertical distance above mean sea level ex pressed in units of length meters or feet Mensor uses the ICAO Standard Atmosphere 1964 to relate absolute pressure 14 696145 psia to altitude Altitude Rate The change in altitude per unit time expressed as meters or feet per minute or per second Ambient Conditions The conditions pressure temperature etc sur rounding the case of the instrument Attitude The orientation of the instrument represented by its angles of inclination to three orthogonal axes Attitude Error The error due to the orientation of the sensor relative to the direction in which gravity acts upon the sensor Barometric Pressure Atmospheric pressure at the point of measure ment frequently stated in terms of the height of a column of mercury See Pressure Relationships Calibration A test during which known values of pressure are applied to the instrument and corresponding out put readings are recorded under specified condi tions GLOSSARY Calibration Curve A graphical representation of the calibration points Calibration Cycle The application of known values of pressure and recording of corresponding output readings over a full or specified portion of the range of an instrument in an ascending and descending direc tion Calibration Record A
29. onmo como 7 e Line Fuses 2 e e e latte O e Pressure Ports Communication Ports Figure 1 3 Rear Panel May 2000 MENSOR CORP EVCTS INTRODUCTION Electrical Module The internal electrical module figure 1 4 consists tem The disk can be removed or replaced by of the input power module a fan a power supply removing the rear panel which is attached by nine an AT compatible computer assembly and a 3 5 screws Note that the plug in printed circuit cards inch disk drive Inside the drive is the disk which are not necessarily in the order illustrated contains the program information to run the sys Speaker Motherboard e Input Power ul Module Power Supply Fan GPIB SOLENOID DRIVER PLA SOLENOID DRIVER i ec Disk Drive Figure 1 4 Internal Electrical Module Top View Display Keyboard Solenoid Driver Solenoid Driver IEEE 488 2 GPIB Serial Disabled Figure 1 5 Electrical Block Diagram MENSOR CORP May 2000 1 3 INTRODUCTION 1 4 Pneumatic Module The pneumatic module figure 1 6 includes two internal high accuracy low drift pressure sensors which are traceable to NIST as secondary stand ards These sensors are used in conjunction with two high resolution pressure regulators t
30. order to control at sub atmospheric pres sures Although both channels can be connected to INSTALLATION a single vacuum pump doing so can create cross channel interference under some conditions and is not recommended MEASURE CONTROL Pressure Ports Devices to be tested are normally connected to the two MEASURE CONTROL ports Ps3 and Pt3 In CONTROL mode these ports can output a precise stable static pressure or a pressure which climbs or falls in an orderly manner pressure rate The EVCTS is tuned for most efficient operation work ing into a one third to one half liter volume at the end of three feet of tubing connected to these ports In MEASURE mode the EVCTS will precisely meas ure the pressure present on a MEASURE CON TROL port up to the full scale range of the sensor Internal relief valves are provided to protect the system from overpressure but this does not reduce the need for good safety practices POWER ON After the pressure connections are secure apply power to the power connector on the rear of the instrument Turn the power switch to ON The instrument will go through a quick initialization process and system check As soon as the system check is completed the system will default to the VENT mode for both channels The display will appear similar to the illustration that follows On the top line the gt symbol indicates that Pt3 is the active channel Local atmospheric pressure is shown on t
31. riage return cr termination character Com mands are not case sensitive and both upper and lower case characters are accepted Parameters Baud rate Select the baud rate which matches that of the host Available EVCTS baud rates are 1200 2400 9600 and 19200 Data Bits Select either 7 or 8 bits Stop Bits Select either 1 or 2 bits Parity Select either Odd Even or None Command Format command format for RS 232 commands is the same as those given for IEEE 488 operation o 1 SHLD o d2 TX i o 9 220 Oy o cc BT o o o 2 2 sG enD o o ses 7 o 9 O O T E One O o Oo OF o Se E o CONNECTOR DB25 CONNECTOR DB25S Figure 4 1 RS 232 Cable May 2000 MENSOR CORP MENSOR EVCTS MAINTENANCE The EVCTS was designed for maintenance free operation User maintenance is not recommended beyond replacement of parts listed in the Spare Parts List If you have questions not covered by this manual the Mensor team is ready to help Call 1 800 984 4200 USA only or 1 512 396 4200 for assistance or E MAIL tech support omen SOr com BEYOND THE WARRANTY Take advantage of Mensor s expert product care Mensor Corporation provides complete mainte nance and calibration services available for the life of the instrument for a nominal fee Our service staff is knowledgeable in the innermost details of all of our
32. the display shows the value currently entered for AP3 default at power up is zero and the bottom line again shows the current mode and the calculated value of AP3 where is the difference between the the Ps3 transducers Press the keys 2nd then 0 for the F1 function and observe that the gt symbol moves to AP3 on the top line to indicate that this channel is now active Press several number keys and notice that the AP3 top line numbers echo each number pressed Do not press Press Fl again 2nd 0 and the active symbol gt will toggle back to the Pt3 channel Again press several number keys and see the Pt3 top line num bers change Changing the numbers on either chan nel takes effect only when followed by pressing The key acts as the Enter this command key Rather than press the clear entry key several times to clear out the entered numbers When the last digit is erased it is replaced with the previous setpoint which remains active INTRODUCTION Press 2nd labeled HELP This changes the display to show the instrument name on the top line and a prompt to press CE to return to the previous display The bottom line shows the instru ment serial number and software version number This display is the only feature available from the HELP function at this time Press CE to restore the display If all has gone well the EVCTS can be put into service by proce
33. 15 239 00 73 89 165 329 00 8 89 16 60 80 18 89 66 150 80 46 67 116 240 80 74 44 1166 330 80 8 33 17 62 60 19 44 67 152 60 47 22 117 242 60 75 00 167 332 60 7 78 18 64 40 20 00 68 154 40 47 78 118 244 40 75 56 168 334 40 7 22 88 66 20 20 56 69 156 20 48 33 119 246 20 76 11 169 336 20 6 67 20 68 00 21 11 70 158 00 48 89 120 248 00 76 67 170 338 00 6 11 21 69 80 21 67 71 159 80 49 44 121 249 80 77 22 171 339 80 5 56 22 71 60 22 22 72 161 60 50 00 122 251 60 77 78 172 341 60 5 00 23 73 40 22 78 163 40 50 56 123 253 40 78 33 173 343 40 4 44 24 75 20 23 33 74 165 20 51 11 124 255 20 78 99 174 345 20 3 89 25 77 00 23 89 75 167 00 51 67 125 257 00 79 44 175 347 00 3 33 26 78 80 24 44 76 168 80 52 22 126 258 80 80 00 176 348 80 2 78127 80 60 25 00 77 170 60 52 78 127 260 60 80 56 177 350 60 2 22 82 40 25 56 78 172 40 53 33 128 262 40 81 11 178 352 40 1 67 29 84 20 26 11 79 174 20 53 89 129 264 20 81 67 179 354 20 1 11 30 56 00 26 67 80 176 00 54 44 130 266 00 82 22 180 356 00 0 56 31 87 80 27 22 81 177 80 55 00 131 267 80 82 78 181 357 80 0 00 32 89 60 27 78 82 179 60 55 56 132 269 60 83 33 182 359 60 0 56 33 91 40 28 33 83 181 40 56 11 133 271 40 83 89 1831 361 40 1 11 93 20 28 89 84 183 20 56 67 134 273 20 84 44 184 363 20 1 67 35 95 00 29 44 85 185 00 57 22 135 275 00 85 00 185 365 00 2 22 36 96 80 30 00 86 186 80 57 78 136 276 80 85 56 186 366
34. 300 millitorr convert the millitorr reading into the current displayed engi neering units From the keypad push 2nd CAL enter password At the prompt type in the true absolute pressure XXX and to enter the reading into memory The display should now indicate the current zero pressure reading for the active channel Press 2nd F1 to toggle the alternate channel and again enter the true pressure at the 2 prompt and then Each channel has a maximum zero offset of 1096 of full May 2000 EVCTS scale Zero values higher than 10 of FS will not be accepted When finished with setting zeros press CE then or to set span or press CE again to exit calibration mode An alternate to entering a new zero value is to just press at the prompt This will remove the current zero value and re establish the factory en tered zero offset for the active channel To set zero over the GPIB send the command Channel ZERO value where Channel is or Ps3 and value is the true pressure XXX To re establish the factory entered zero over the bus send CHANNEL space ZERO space No tice that the only difference between this and the Zero query command is the space added between zero and the question mark Setting Sensor Span With both channels warmed up and in MEASURE mode apply a known absolute pressure equal to or near the span of the sensor The value must
35. A L3 rl Q 100 inHg A XDCR Ps3 100 inHg A XDCR 19 Oo E T 110 inHg A INTRODUCTION eo ree o VENT L4 9 L10 VENT reo NOTES 1 For single source pressure plug one of the two external SUPPLY ports or for independent sources disconnect the internal tube marked XX which joins the two controllers 2 Solenoid valves L1 through L11 are 5 vdc 1 5 w normally closed 3 Solenoid valve L6 is unused or not installed in some configurations MENSOR CORP Figure 1 7 Pneumatic Schematic May 2000 Pt3 SUPPLY SEE NOTE 1 Pt3 EXHAUST Pt3 OUTPUT Ps3 OUTPUT Ps3 EXHAUST Ps3 SUPPLY SEE NOTE 1 1 5 INTRODUCTION Chassis Assembly The chassis assembly acts as the housing for the system The electrical and pneumatic modules are each self contained and can be replaced individu ally using basic hand tools System accuracy is maintained when either module is replaced be cause the transducers and their calibration data reside in the pneumatic module Rear EVCTS The only moving parts in the EVCTS are the fan the disk drive mechanism the pneumatic flow controller diaphragms and valves and the solenoid valve plungers There are no internal user adjust ments or setup switches The layout of the internal system is illustrated in figure 1 8 1 0 GPIB SOLENOID
36. Defaults F7 Power On Defaults Figure 9 6 Advanced CMOS Setup Screen MENSOR CORP May 2000 9 9 APPENDIX COMMANDS QUERIES AND DEFAULT VALUES Table 9 7 lists all the instrument specific commands and queries and lists factory set default values in the center column Table 9 7 Commands Queries And Default Values EVCTS Command Default Query ADDRESS 1 ADDRESS X none CHAN CONTROL ON CONTROL DEFAULT none X X X DOM ENGLISH none X X ERROR F1 F1 F2 F2 FILTER 90 FILTER X ID LOCK LOCK LOWERLIMIT LOWERLIMIT X MAXRANGE MEASURE MEASURE X X MINRANGE OUTFORM NORMAL OUTFORM PASSWORD none X SETPT none SETPT SPAN none SPAN X STABLE STABLETIME 2 STABLETIME STABLEWIN 0 004 inHg STABLEWIN STANDBY none STANDBY STEP STEP UNITS UNITS UPPERLIMIT UPPERLIMIT VENT none VENT WINDOW 0 025 inHgA WINDOW ZERO none ZERO May 2000 MENSOR CORP MENSOR EVCTS GLOSSARY Absolute Pressure A pressure that is referenced to the absence of all other pressure that is referenced to true zero pressure See Pressure Relationships Accuracy The difference between the average of multiple measurements of a value and the true value See Uncertainty Air Speed The distance a body moves through the air per unit
37. N Table 4 1 continued EVCTS COMMAND DATA RESPONSE FUNCTION Sdata 70r8 Sets the serial data bits SData None Returns the serial data bits Sparity EVEN ODD Sets the serial parity or NONE Sparity None Returns the serial parity Sstop 10r2 Sets the serial stop bits Sstop None Returns the serial stop bits Setpt within lower Sets the control setpoint for the active channel and upper limits Setpt None Returns the control setpoint for the active channel Span desired Alters the span value so that the instrument reads the value sent when at the pressure or current pressure clears previous value Span None Returns span scale factor Stable None Returns YES if current channel is stable StableTime 0 65535 Sets the stable time to the number of seconds specified StableTime None Returns the stable time StableWin within lower Sets the stable window and upper limits StableWin None Returns the stable window Standby None If modes are linked all channels are placed in the Standby mode otherwise the active channel is placed in Standby Standby None Returns YES if active channel is in the Standby mode NO otherwise Step within lower Sets the control step for the active channel and upper limits Standby None If modes are linked all channels are placed in the Standby mode otherwise the active channel is placed in Standby S
38. OLUME CONTROLLER PRESS e PRESSURE PRESSURE CALIBRATION CALIBRATION PRESSURE STANDARD The recommended calibration standard is a piston gauge type deadweight gauge with an uncertainty of 0 01 of reading or better For measuring vac uum a diaphragm type vacuum gauge with an accuracy of 0 05 of reading at 250 to 300 millitorr is recommended CALIBRATION MEDIUM The recommended calibration medium is dry ni trogen or clean dry instrument air For low pres sure ranges 20 psi head pressure differences between the standard and the EVCTS can cause errors See Pressure Correction in the Ap pendix CALIBRATION PROCEDURES Figure 6 1 Calibration Setup illustrates a typical setup for either local or remote calibration In the figure the additional equipment required for re mote calibration is shown as optional In the calibration setup illustration the Pressure Standard is normally a deadweight test instru COMPUTER optional GPIB SHUT OFF STANDARD DWT DIAPHRAGM TYPE VACUUM GAUGE Fa NOTE DISCONNECT WHEN VACUUM GAUGE RANGE IS EXCEEDED Figure 6 1 Calibration Setup May 2000 CALIBRATION ment and the volume controller refers to a hand operated variable volume pressure vernier device A diaphragm type vacuum gauge is recommended over the gauge tube type of vacuum se
39. OR CORP three available metric units of measure mBar mmHg and kPa Use the or key to step through to the desired units then press The selected units will immediately be assigned to both chan nels This menu function offers the two ENG LISH measurement units inHg or psi Again use the or key to select the desired units Press to simultane ously assign the selected units to both channels Enter this menu to set the GPIB address of the EVCTS Addresses of O to 30 are allowed Not active for this unit Enables STANDBY for both channels Not available while Ps3 is displayed MEAS CONT VENT Other Functions CE May 2000 LOCAL OPERATION Places the EVCTS in MEASURE mode to accurately measure the pressure appear ing on the MEASURE CONTROL ports Puts the EVCTS in CONTROL mode The pressure value appearing on the top line of the display will be presented to that channels MEASURE CONTROL port Not available while Ps3 is displayed This function relieves the pressure from the EVCTS by venting the pneumatics to atmosphere within the EVCTS case Not available while Ps3 is displayed The four operation keys CE 1 and are active while in the menu modes They perform as follows CE acts as a backspace during numeric entry or returns to the previous screen in menu mode If a sub menu is dis played then it will require pressing CE at least twice to get
40. PRECISION INSTRUMENTS amp SYSTEMS USER S MANUAL PN 0014736001 C ENGINE VANE CONTROL TEST SET CORPORATION CODE 201 BARNES DRIVE SAN MARCOS TEXAS 78666 512 396 4200 FAX 512 396 1820 VERSION WEB SITE http www mensor com SN WARRANTY Allproducts manufactured by Mensor Corporation are warranted to be free of defects in workmanship and materials for a period of one year from the date of shipment No other express warranty is given and no affirmation of Seller by words or actions shall constitute a warranty SELLER DISCLAIMS ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSES WHATSO EVER If any defect in workmanship or material should develop under conditions of normal use and service within the warranty period repairs will be made at no charge to the original purchaser upon delivery of the product s to the factory shipping charges prepaid If inspection by Mensor Corporation or its authorized representative reveals that the product was damaged by accident alteration misuse abuse faulty installation or other causes beyond the control of Mensor Corporation this warranty does not apply The judgment of Mensor Corporation will be final as to all matters concerning condition of the product the cause and nature of a defect and the necessity or manner of repair Service repairs or disassembly of the product in any
41. R AS IS WITHOUT WARRANTY OF ANY KIND EITHER EXPRESS OR IMPLIED INCLUDING BUT NOT LIMITED TO WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE THE ENTIRE RISK OF THE QUALITY AND PERFORMANCE OF THE SOFTWARE PROGRAM IS WITH THE END USER MENSOR AND ITS SUPPLIERS SHALL NOT BE HELD TO ANY LIABILITY FOR ANY DAMAGES SUFFERED OR INCURRED BY THE END USER INCLUDING BUT NOT LIMITED TO GENERAL SPECIAL CONSEQUENTIAL OR INCIDENTAL DAMAGES INCLUDING DAMAGES FOR LOSS OF BUSINESS PROFITS BUSINESS INTERRUPTION LOSS OF BUSINESS INFOR MATION AND THE LIKE ARISING FROM OR IN CONNECTION WITH THE DELIVERY USE OR PERFORMANCE OF THE SOFTWARE PROGRAM FCC RADIO FREQUENCY EMISSION NOTICE This equipment has been tested and found to comply with the limits for a Class A digital device pursuant to Part 15 ofthe FCC Rules These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment This equipment generates uses and can radiate radio frequency energy and if not installed and used in accordance with the instruction manual may cause harmful interference to radio communi cations Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his or her own expense USE SHIELDED CABLES TO CONNECT EXTERNAL DEVICES TO THIS INSTRUMENT TO MINIMIZE RF RADIATION
42. Returns the next error in the error queue F1 None Same as pressing F1 on keyboard F2 None Same as pressing F2 on keyboard F3 None Same as pressing F3 on keyboard Filter 0 99 99 Sets the measured reading exponential filter percent for all channels Filter None Returns the filter percent Id None Returns s sn v version MENSOR EVCTS ssssss v w Keylock Yes or No Locks or unlocks keyboard Keylock None Returns YES or NO Linked Yes or No Links modes if YES independent if NO Linked None Returns YES or NO List None Returns a list of valid channel names LowerLimit within sensor Sets the lower control limit for the active channel range and less than upperlimit LowerLimit None Returns the lower control limit for the active channel Measure None If modes are linked all channels are placed in the Measure mode otherwise the active channel is placed in Measure Measure None Returns YES if active channel is in the Measure mode NO otherwise Outform 1 2 or 3 Sets the output format Outform None Returns the output format see Outform Formats text Range None Returns the range of the active channel Rate None Returns the rate reading of the active channel RUnits Sec Minor Sets the rate units Hour RUnits None Returns the rate units Sbaud 300 1200 Sets the serial baud 2400 4800 9600 1920 Sbaud None Returns the serial baud Continued on next page MENSOR CORP May 2000 REMOTE OPERATIO
43. SOR CORP May 2000 vii TABLE CONTENTS 5 MAINTENANCE Beyond the Warranty Program Disk Replacement Module Replacement Electrical Module CMOS Memory Battery Replacement Spare Parts List CALIBRATION Calibration Environment Calibration Pressure Standard Calibration Medium Calibration Procedures Setting Sensor Zero Setting Sensor Span SPECIFICATIONS General Specifications Measurement Specifications Control Specifications OPTIONS Relief Valves Transport Case Rack Mount Kit APPENDIX Conversion Factors Pressure Conversion Factors psi Conversion Factors Millitorr Temperature Conversion Table Measurement Units Materials in Contact with Pressure Medium Head Pressure Correction Gas Head Pressure Calculation IEEE Connector and Pin Functions CMOS Setup ie db RUM Us Commands Queries and Default Values 10 GLOSSARY 11 viii May 2000 EVCTS MENSOR CORP EVCTS TABLE OF CONTENTS REFERENCE LIST OF FIGURES AND TABLES Figures 1 1 System Block Diagram 1 1 1
44. UR Standard Atmospheric Pressure 5 a 5 5 2 2 Zero ft altitude 9 4 14 6961 5 Dolo 9 lt 9 9 22 09 ji 4 U Gio 29 9213 in HgA C 2 2 e 2010 1013 250 millibars gt Y 760 mmHgA Barometric Pressure 760 torr 3 2 101 325 kilopascals E Sa EO ditus A 33 9602 ftH20 O 20 C mp 5 5 29 Values approximate Refer ma 3415 to pressure conversion tables 02 the Appendix nu Absolute Reference Perfect Vacuum Figure 10 1 Pressure Relationships May 2000 10 3 GLOSSARY 10 4 Range The measurand values over which the measuring device is intended to measure specified by the lower and upper limits See also Full Scale and Span Rate See Altitude Rate or Pressure Rate Reference Pressure The pressure relative to which a differential pres sure instrument measures pressure Repeatability The ability of an instrument to reproduce output readings when the same pressure value is applied repeatedly under the same conditions and in the same direction Resolution Output The maximum number of distinguishable values of output over the range of the instrument Stated another way the least detectable magnitude of change in the pressure Response Time The length of time required for the output of the instrument to rise to a specified percentage of its final value as a result of a step change of pressure
45. al height from mean sea level especially of a point on the earth s surface used in making local corrections to barometric readings Environmental Conditions Specified external conditions shock vibration temperature etc to which an instrument may be exposed during shipping storage handling and operation EOI A GPIB line that is used to signal the end of a device dependent message Error The algebraic difference between the indicated value and the true value of the pressure usually expressed in percent of full scale FS See Full Scale Full Scale The upper limit of the device range frequently noted as FS See also Range and Span Gauge Pressure The difference between atmospheric pressure and a variable pressure See Pressure Relationships GET Group Execute Trigger A GPIB interface message that causes all devices with the GET capability and are currently ad dressed to listen to initiate a programmed action for example to store the current reading take a sweep on an oscilloscope etc The GET command provides a means of triggering multiple devices simultaneously GPIB General Purpose Interface Bus A common name for the communication system defined in IEEE 488 1 1987 It is also known by the following names IEEE 488 1 IEEE bus HP IB ASCII bus PLUS bus The international version of May 2000 EVCTS the GPIB is defined in the IEC 625 1 standard and is identical to the GPIB except for the
46. alibration Certificate and a Warranty Certificate INITIAL INSPECTION Your new Mensor instrument was thoroughly tested and inspected at the factory and it was free of dings dents and scratches when it was packaged for shipment Please examine it now for signs of shipping damage Report any apparent damage to the carrier immediately INTRODUCTION MEET YOUR EVCTS The Engine Vane Control Test Set EVCTS is a special purpose PCS 400 designed to calibrate jet engine pressure transducers It consists of a self contained computerized high accuracy two chan nel pressure management system integrated into a single compact unit The system is comprised of a front panel assembly a rear panel an electrical module a pneumatic module and a chassis to tie it all together The system functions either as a bench top or a rack mounted instrument It can operate in local mode to accept front panel input or in remote mode to communicate with external devices The installed software is specifically de signed to test Engine Vane Control parameters where numbers for the Pt3 and AP3 values are input and the Ps3 and Pt3 pressures are output to the rear panel Notice that Pt3 Ps3 AP3 A brief description of the major elements of the system follows Pneumatics Module Electrical Module Pneumatics Pneumatics Front Panel Display Figure 1 1 System Block Diagram May 2000 1 1 INTRODUCTION Instrume
47. arison with primary standards traceable to the National Institute of Standards and Size ua a 2 Width 17 05 inches 43 31 IES S an ar 9 db e RUN 19 00 inches 48 26 with rack adapter 0 0001 psi whichever is greater Height 6 97 inches 17 70 cm Depth 20 00 inches 51 0 cm without fittings Mensor does not use RMS or RSS techniques to make specifications appear any better than they dao Weight actually are Primary standard uncertainties should be used in the evaluation of equipment 50 00 lbs 22 68 kg standard performance The specifications shown by Mensor 54 00 lbs 24 49 kg with rack adapter are worst case conditions and allow the user to 70 70 lbs 32 07 kg shipping w rack kit make an honest evaluation of the instrument Men sor reserves the right to change specifications with out notice Front View O 5 25 13 34 Y O SET o 4 5400 pressure CALIBRATION SYSTEM 100 inHgA 100 inHg 838 em 17 05 43 31 lt 19 00 48 26 gt Overall width with Rack Mount Flanges attached Side View 6 97 17 70 J lt 20 0 50 80 cm gt Add 0 45 inches 1 14 cm to height with feet attached Figure 7 1 Dimensional Outline MENSOR CORP
48. completely out of the menus and back to the primary display The key is a numeric sign acceptable but not required if a positive number entry is appropriate at the time or else a step forward into the sub menus for each press when in a menu function In CON TROL mode each press of the key will increment the control setpoint by the pre defined step value The key is a numeric sign required if a negative number entry is appropriate at the time or else a step backward through the sub menus for each press when in a menu function In CONTROL mode each press of the key will decrement the control setpoint by the pre defined step value The key is the Enter or Execute key for either the value or function that is currently displayed LOCAL OPERATION Dual Passwords There are two levels of passwords in the system A line level or zero password allows access to Zero adjustments and a master password that will ac cess all protected functions including changes to passwords In order to change either password the current master password must be entered Since passwords are seldom used they are easily forgot ten Please keep a written record of newly entered passwords The master password will work for any protected function until it is changed through the CAL PASS WORD function Either password can be from one to six digits long To allow line technicians to easily make zero adjustments the zero pa
49. connector GPIB Address The address of a device on the GPIB composed of a primary and possibly a secondary address The EPRTS does not support secondary addressing Gravity Correction The correction factor applied to measurement processes involving mass to account for the gravity constant exerted at the site of the measurement GTL Go To Local A GPIB interface message that causes the ad dressed listener s to go to the LOCAL front panel mode HP IB Hewlett Packard Interface Bus Another name for the GPIB referring to the origina tor of the bus Hysteresis The maximum difference in output at any pressure value within the specified range when the value is approached first with increasing and then decreas ing pressure IEC 625 1 International version of the GPIB IEEE 488 1 1987 The standard defining the GPIB Interface Message A message from the GPIB controller to all devices used to manage the bus and provide some control over the devices on the bus See Device Dependent Message Linearity The closeness of a calibration curve to a specified straight line expressed as a percentage of full scale deviation Line Pressure The highest pressure within a system which can be present at the pressure sensor See Reference Pressure Listener A GPIB device that receives device dependent mes sages from a talker MENSOR CORP MENSOR EVCTS LLO Local Lockout A GPIB interface message t
50. ction 1 1 1 7 K oou aah cena we sees 1 2 3 1 7 2 Functions and Functions List 3 2 3 4 Menu Descriptions 3 4 INDEX L Local Op ration 5 3 1 3 6 M 5 1 5 4 CMOS Memory Battery Replacement 5 2 Electrical Module 5 2 Module 5 1 Program Disk Replacement 5 1 Spare Parts List 7 ta eae pea 2 5 3 1 2 2 1 Measure Control Ports 2 1 Measurement Units Table 9 4 Mechanical 7 2 Menu Key 3 5 Menuet ree AA A ra 3 6 Mode Localia 355a de S 1 1 Pressure Bate Limit K s c s 7 3 Remotes 222 x6 1 1 Module Electrical 522555 Seow ses 2 1 1 POWEL gt is n REUS ABS 1 3 EPTleullati amp XOU ete BY 1 1 5 1 Mounting 2250 lt 2 A A XS x 2 1 7 2 N National Institute of Stds and Tech NIST 1 7 NPT ms A See etuer Cam e e fa 1 1 2 1 7 2 Operating Environment 7 2 Operation Local 1 1 3 1 3 6 Operation Remote 1 1 4 1 4 11 Options nde oe o 8 1
51. cy Zero Drift Time after warm up 0 01 FS maximum 30 days Zero may be reset without affecting span or linearity Span Drift Time 0 01 FS max 90 days Span may be reset without affecting zero or linearity Internal Pneumatic Volume Measure Control Ports Measure Mode 30 cc Control Mode 238 cc External Pneumatic Volume Maximum 1 Minimum 0 1 100 MENSOR CORP EVCTS CONTROL SPECIFICATIONS Standard Pressure Ranges 0 100 inHga Ps3 0 100 inHga Source Pressure Instrument air or dry nitrogen Recommended SPECIFICATIONS Pressure Rate Limit Mode A pressure rate of slow or fast may be selected to set the maximum slew speed between selected control points The default value is Fast Maxi mum and minimum slew speed is dependent upon pressure range per the following table Table 7 2 Minimum Maximum Slew Speed tthe S I t pressure at the Supply por Full Scale Table 7 1 Slow Medium Fast Recommended Pressure at the Supply Port 0 1 0 5 1 0 i inH inH Channel Supply Port Pressure BHO SEG Ingrese f 0 1 0 5 1 0 Pt3 0 110 inHga inHg sec inHg sec inHg sec Ps3 0 110 inHga Accurate external regulation not required Note Pt3 and Ps3 Supply ports are internally con nected Exhaust Pressure Vacuum pump required for absolute pressure control A minimum pump capacity of 21 liters
52. de a concerted effort to provide complete and current information for the proper use of the equipment If there are questions regarding this manual or the proper use of the equipment contact Mensor Corporation at TEL 1 512 396 4200 TEL 1 800 984 4200 USA only FAX 1 512 396 1820 WEB SITE http www mensor com E MAIL sales mensor com tech support mensor com MENSOR CORP May 2000 iii PREFACE EVCTS PACKAGING FOR SHIPMENT If the product must be shipped to a different location or returned to Mensor for any reason through a common carrier it must be packaged properly to minimize the risk of damage The recommended method of packing is to place the instrument in a container surrounded on all sides with at least four inches of shock attenuation material such as styrofoam peanuts TRADEMARKS Mensor is a registered trademark of Mensor Corporation All other brand and product names are trademarks or registered trademarks of their respective companies The EVCTS instrument contains software licensed from Microsoft Corporation 1996 2000 Mensor Corp All rights reserved SOFTWARE LICENSE AGREEMENT This product contains intellectual property i e software programs that are licensed for use by the end user customer hereinafter End User This is not a sale of such intellectual property The End User shall not copy disassemble or reverse compile the software program THE SOFTWARE PROGRAMS ARE PROVIDED TO THE END USE
53. eding to the Installation section of the manual which is next Instructions for operat ingthe instrument manually follow that in the Local Operation section IF YOU HAVE PROBLEMS If you have problems using your EVCTS and you don t find the answer in your manual contact Mensor at 1 800 984 4200 USA only or 1 512 396 4200 for personal assistance or at any of the on line addresses listed in the front of the manual We are ready to help Mensor s concern with the welfare of this instru ment is not limited to the warranty period We provide complete repair services for the life of the instrument as explained in Section 5 Mainte nance CALIBRATION SERVICES In addition to servicing our own products Mensor can perform a complete pressure calibration serv ice up to 20 000 psi for all of your pressure instruments This service includes a Certificate of Compliance and Calibration and the record of traceability to the pressure standards of the Na tional Institute of Standards and Technology NIST May 2000 INTRODUCTION EVCTS User s Notes 1 9 200 MENSOR CORP MENSOR EVCTS INSTALLATION MOUNTING The instrument can be set up on a table top or it be rack mounted For rack mount installation see the mounting instructions in Section 8 Op tions The special sensors used in the EVCTS are rela tively insensitive to tilt and vibration However to further assure stabili
54. emove power cord 2 Remove the top cover by removing the three screws on the top rear 3 Remove the pressure fittings from the rear ports 4 To remove the pneumatics module remove the four screws on the rear panel that screw into the pressure manifold and the two screws under the bottom plate that hold down the module Disconnect all the pneu matic module cables from the electrical mod ule Then slide the pneumatic module forward slightly to disengage it from the key hole slots in its base and lift it out the top of the instrument 5 remove the electrical module remove the cables to the pneumatic module and the front panel and remove the two screws under the bottom plate that hold down the module Slide the module forward slightly to disen gage the key hole slots in its base and lift the module out the top 6 Reverse the order to replace the module May 2000 Electrical Module To gain access to the circuit boards inside the electrical module without removing the module remove the instrument top cover 3 screws and the left side panel 2 screws This allows access to the ten screws that secure the module cover to the module chassis four screws at the top and 2 screws each at the front left and right sides Re move these ten screws then lift the module cover straight up to remove it CAUTION ESD PROTECTION REQUIRED The proper use of grounded work surfaces and per sona
55. er increase in density as the pressure increases To determine the density of a gas at a specific pressure multiply the absolute pressure by the density from the following table For gas the head pressure difference due to temperature changes within the compensated temperature range will be insignificant Table 9 6 Gas Density Gas 23 Density psi pounds in Dpsi Air Dry 2 9315 X 10 Argon A 4 0443 X 10 Carbon Dioxide 4 4824 X 10 Helium He 4 0466 X 107 Hydrogen 2 0379 X 10 Nitrogen N2 2 8355 X 10 Head Pressure Calculation The pressure at the input port P2 of figure 9 1 of the Device Under Test DUT will be a positive number if the standard is positioned higher than the DUT Ifthe standard is lower than the DUT the head pressure correction will be a negative value The equation used to calculate the head pressure is P2 P1 1 h x Dpsi h Difference in vertical height between the center lines of the two pressure ports Dpsi Gas density refer to the Gas Density table Pressure r1 Standard psi h in inches Device Under P2 Test psi Figure 9 1 Head Pressure Calculation MENSOR CORP May 2000 9 5 APPENDIX IEEE CONNECTOR AND PIN FUNCTIONS 24 pin Female Connector viewed from rear of instrument EVCTS PIN DESCRIPTION
56. eu RT bon Ps 1 1 Weight one 406 eU oh se 7 1 Z ud oe e o oer ke qa I teh wm ad d 6 2 Zero Drift as Resume A 7 2 INDEX User s Notes EVCTS May 2000 MENSOR CORP
57. ey ii ln MAS 5 1 EXHAUST abis cm 2 1 Exhaust Pressure 2255 a 7 3 a ZL 1 3 1 6 FCC Radio Frequency Emission Notice iv Filters sre s aq 7 2 FiUGDSS y y ae s p eR Se HHHH HH 7 2 Adaptors y S 1 1 2 1 Flow Controller 1 6 BrontPahnel soe cane cheese ecos rele uS LR 1 2 7 1 Assembly 2 2 2 2 xxx S x Tux 1 1 Display e re i uere ines gates a 1 2 7 2 ws 1 2 7 2 FUSES io a os Se od 5 3 G XaSeS sun 7 2 Glossary 5 552 ek op Rex Re o oa 10 1 10 4 Gravity Orientation Effect 7 2 H Head Pressure Calculationy at did A tdo do 9 5 Gas Density 2 4 oso 22 49 de 4 5 E ode os 9 5 Health and Safety Warnings iii IEEE 488 y W2 hc Wi 4 1 Capability Codes 4 Connector and Pin 9 6 Initial 1 1 2 1 5 1 5 4 Mounting uc mE RT RERO EM ESTE S 2 1 Power Oh uuo Sen ve ERE ke PIE 2 1 Pressure Connections 2 1 Internal Pneumatic Volume 7 2 Internal System Layout Illustration 1 6 Introdu
58. figure 9 3 5 Apply power to the electrical module and monitor and watch the screen After a few seconds the monitor will display instructions on how to continue or it will display an error message such as 693 the F1 key to continue or Hit lt Del gt if you want to run SETUP Follow the instructions on the screen to get to the BIOS setup menu Figures 9 4 9 5 and 9 6 are examples of the screens displayed for CMOS setup routine with a 1992 version of American Megatrends Inc AMI BIOS and one specific motherboard These are typical but may vary for different software and hardware configurations Enter the data into both the standard and the advanced CMOS setup screens as shown in the examples or as appropriate for the specific installation After all of the data is entered and checked press F10 from screen 9 4 to save these settings and exit to DOS Cycle the EVCTS power off and back on Contact Mensor if there are still problems initializing the system BIOS SETUP PROGRAM AMIBIOS SETUP UTILITIES C 1992 American Megatrends Inc All Rights Reserved STANDARD CMOS SETUP ADVANCED CMOS SETUP AUTO CONFIGURATION WITH BIOS DEFAULTS AUTO CONFIGURATION WITH POWER ON DEFAULTS CHANGE PASSWORD HARD DISK UTILITY WRITE TO CMOS AND EXIT DO NOT WRITE TO CMOS AND EXIT Standard CMOS Setup for Changing Time Date Hard Disk type etc 44 Select 2 1
59. hat causes all devices that respond to the Local Lockout command to ignore local control MLA My Listen Address A GPIB interface message used to command a device to be addressed as a listener MTA My Talker Address A GPIB interface message used to command a device to be addressed as a talker Operating Conditions See Environmental Conditions Output The electrical or digital quantity produced by an instrument which is a function of the applied pressure Overpressure Rating The pressure which may be applied to the sensing element or the case as specified of a sensor with out damage to either the sensing element or sensor case as specified GLOSSARY Parallel Poll The process of polling all configured devices at once and returning a composite poll response The EVCTS does not support Parallel Polling See Se rial Poll Peak Pressure The greatest or if desired the least pressure sensed during a measurement session Precision The ability of an instrument to repeat an output when measuring a given quantity under identical conditions Pressure Medium The fluid gas or liquid which comes in contact with the sensing element in the pressure chamber Pressure Rate An orderly change in pressure over a specified time Pressure Relationships The relationship of various pressure terms are illustrated below in figure 10 1 PRESSURE i Differential Pressure PSID tutos Sys DROP O
60. he Sensor Absolute 6 2 Specifications ec see ht d eet Dy es 7 1 7 3 Stability Controlled Pressure 7 3 Standards go RO 7 1 Supply Pressure see also Source Pressure 7 3 Supply Pressure 2 1 Switch POWER cbr eae LIA a ts 1 7 2 1 Setup A E ws 1 6 Voltage 1 2 System 3 1 MENSOR CORP MENSOR EVCTS T Temperature Effects 7 2 Temperature Conversion Table 9 3 Time e 52 504 we 5 5 ee vay 7 2 SEU 22224245402 7 3 Sen up Sub oput den euo edo ty 2 1 7 2 Traceability Calibration 7 1 Trademarks 5 2 5o 2959525 E XU iv Tree Men s u L o muy a auc dd Biles le dy 3 6 9 10 Troubleshooting Guide 5 2 Error Symptoms and Solutions 5 3 Uncertainty lt wise Ee A ex 6 1 7 1 May 2000 INDEX V Valves Z S s MS S k ese Rid 8 1 Solenoid sey L uh eke eae 9 SEG 1 6 Volume Internal Pneumatic 7 2 W Warmip 5o vade A teer eft 2 1 7 2 Warnings and Caution iii 5 2 6 2 8 2 Warranty n pe ee a ii 1 7 5 1 Ger licate y 1 5 9 Wee tO S
61. he bottom line of channel Pt3 Press 2nd which is labeled HELP The screen now shows the instrument name on the top line and a prompt to press CE to return to the previous display The serial number and software version are displayed on the bottom line A warm up period of at least 45 minutes is advised for greatest accuracy The EVCTS is now ready for service May 2000 2 1 INSTALLATION User s Notes EVCTS 2 2 May 2000 MENSOR CORP MENSOR EVCTS LOCAL OPERATION This section describes the proper procedures for operating the EVCTS from the front panel Instruc tions for operating the EVCTS from an external computer are covered in the next section Following the procedures provided in these two sections and Section 6 Calibration will ensure maximum accu racy and dependability of your instrument SYSTEM OVERVIEW The Engine Vane Control Test Set consists of two independent pressure measuring pressure con trolling sub systems or channels on the pneumat ics module These two pressure channels are identified as Pt3 and Ps3 A third channel identi fied as AP3 is a variable quantity that can be defined by the operator With the system in CON TROL mode the relationship of these three chan nels is Pt3 AP3 Ps3 In effect a controlled pressure setpoint can be assigned to Pt3 another positive quantity can be assigned to and the EVCTS will respond with a
62. instruments We maintain units that are in operation in many different industries and in a variety of applications and by users with a wide range of requirements Many of these instruments have been in service for over twenty years and continue to produce excellent results Returning your instrument to Mensor for service benefits you in several ways a Our intimate knowledge of the instrument assures you that it will receive expert care b In many cases we can recommend for your consideration upgrading to the latest en hancements c Servicing our own instruments which are used in real world applications keeps us informed as to the most frequent services required We use this knowledge in our con tinuing effort to design better and more ro bust instruments PROGRAM DISK REPLACEMENT In order to replace the system program disk first remove the power cord from the instrument Then remove the rear panel by removing the five screws holding it to the frame and the four screws near the pressure ports The disk drive is located in the upper center at the rear ofthe instrument The disk is ejected by pressing the eject button Push the new disk into the disk slot until it locks in place Replace the rear panel and restore the instrument power Turning on the instrument will reboot the EVCTS and load the new program MAINTENANCE MODULE REPLACEMENT To replace an electrical or a pneumatic module follow these steps 1 R
63. l Pt3 AP3 display state selecting either STANDBY MEASURE CONTROL or VENT will apply the selected mode to both channels In the alternate Pt3 Ps3 display state both channels automat ically lock into the MEASURE mode STANDBY CONTROL and VENT are locked out until the display is returned to the Pt3 AP3 state Not used CAL provides entry to the zero and span calibration functions and to the change passwords function After pressing CAL press or several times to step through the ZERO SPAN and PASS WORD sub menus To enable any of these press while the desired function is on the display ZERO A zero password is required in order to change either channel s zero off set When the system is ready to accept a change to the current zero offset a prompt to enter the new value will appear in the display See the Calibration section of the manual for instructions on deter mining the correct zero offset Note At the user s discretion the zero password can be disabled so that line operators can reset zero at will SPAN A separate master password is needed to change either channel s span value When the system is ready to accept a change to the current span value a prompt to enter the new value will appear in the display See the Calibration section of the manual for instructions on cali brating the sensor s span Note The mas ter password can be changed but it cannot be disabled PASSWORDS En
64. l wrist straps are required when coming into contact with exposed circuits printed circuit boards to prevent static discharge damage to sen sitive electronic components All of the circuit boards in the module are compat ible with IBM AT format Personal Computers PC s Most are purchased from various manufac turers they may differ in appearance and position from one unit to the next but their functionality remains the same The exceptions are that the Solenoid Driver and PLA boards are proprietary designed and assembled by Mensor CMOS Memory Battery Replacement Replacement of the CMOS memory backup battery see figure 5 1 every two years is recommended in order to preclude its complete discharge If the battery is allowed to discharge before it is replaced the Basic Input Output System BIOS data stored in the CMOS Random Access Memory RAM will belost When this occurs the internal computer can not initialize until the BIOS data is restored To restore BIOS data first replace the battery with a fresh one then run the CMOS setup routine to restore lost data as described in the Appendix Section 9 To replace the CMOS battery first gain access to the interior of the electrical module as stated above NOTE The battery will be either a 3 6V or a 6V lithium battery The replacement battery must be the same voltage level lithium battery as the one being re placed May 2000 EVCTS la If the battery is alread
65. menu trees near the instrument until operators are familiar with the various keystrokes and functions The following descriptions are of functions and by inference require pressing the 2nd key prior to pressing the associated function key Instructions for pressing the 2nd key are omitted from this text in favor of brevity over redundancy To back out of any menu or sub menu press one or more times F1 The F1 function toggles between selecting the left Pt3 or right AP3 or Ps3 chan nels The leading gt symbol designates which channel is active A channel must be active to change the output pressure setpoint top line value Changing the primary mode STANDBY MEASURE CONTROL or VENT on either channel forces the change to both channels In addition when in the calibration mode the active channel is the channel having its zero offset or span value changed To change the output pressure setpoint sim ply make the appropriate channel active then press the number keys for the de sired value The new value appears on the top line as the numbers are entered When the displayed value is correct press 7 Next press CONT and the control ler for that channel will immediately slew the output pressure to the newly com manded value May 2000 3 1 LOCAL OPERATION F2 F3 CAL The F2 function toggles the display to show either Pt3 and AP3 normal or to show Pt3 and Ps3 alternate In the nor ma
66. n output pressure on the Ps3 MEASURE CONTROL port which is the difference between the Pt3 pressure and the AP3 value Notice that P3 will accept only positive values within the range of Pt3 KEYPAD Local operation is accomplished through the key pad and by observing the display The fifteen dual purpose function keys enter either the numeric value or operation printed on the key face or if the 2nd key is pressed first then the key enters the menu function printed directly above the key STBY MEAS CONT VENT h ce uU ES ES UNITS COMM METRIC ENG GPIB SERIAL Sse ES CAL TEST LIMITS ES EW nasa Figure 3 1 Keypad LOCAL OPERATION Pressing 2nd causes the next key press to shift into the menu function mode Notice that throughout this manual characters en closed in square brackets indicates a single key stroke For example 0 indicates pressing the zero key unshifted whereas 2nd F1 indicates pressing 2nd then 0 to execute the F1 function Where the text might say Go to VENT mode the meaning is press the two key sequence 2nd then CE to execute the VENT mode Functions A description of each available function is pre sented below followed by a table summary A graphic menu tree is placed at the end of this section and a larger foldout of the same menu tree will be found in the rear cover pocket It might prove helpful to have a photocopy of one of the
67. ndow Zero desired Alters the zero value so that the instrument reads the value sent when at the pressure or current pressure clears previous value Zero None Returns zero offset MENSOR CORP May 2000 REMOTE OPERATION RS 232 SERIAL COMMUNICATION This section of the manual applies to the serial communication capability Refer to the GPIB por tion at the beginning of this section of the manual for additional information relating to commands and responses The serial communication port allows the EVCTS to communicate with computers terminals and mo dems referred to as the host in RS 232 interface format Communicating over the serial port does NOT disable the front panel keypad The Keylock command should be issued to avoid conflicts while operating over the bus Cable Requirements RS 232 communications are transmitted over a three conductor shielded cable terminated in a standard DB 25 connector on the instrument end and usually the same DB25 connector on the host end Figure 4 1 illustrates the proper pin connec tions to hook up a host to an EVCTS Setup Before putting the RS 232 interface into operation the various communication parameters must be EVCTS selected from the SERIAL setup menu Refer to the menu tree provided with this manual The parame ters selected must match the host computer Com mands must be sent in ASCII format and terminated with either a line feed 1f or a car
68. nsor for calibrating sub atmospheric pressures A vacuum source with a minimum capacity of 21 liters per minute is recommended NOTE The recommended units for making zero or span adjustments are psi Other engineering units might add a small roundoff error CAUTION DO NOT APPLY MORE THAN THE MANUFACTURERS RECOM MENDED MAXIMUM PRESSURE TO THE VACUUM GAUGE TUBE OR IT MAY EXPLODE The maximum pressure for the Hastings gauge tubes provided by Mensor is 50 psia But energizing the gauge tube at pressures above atmos phere 15 50 psia will decrease the life and accuracy of the tube With the EVCTS connected to the Calibration Setup close both vent shut off valves and set both channels to MEASURE mode Evacuate the transducers to a low pressure that will still maintain a viscous flow typically 250 to 300 millitorr At pressures lower than this the actual pressure at any particular point in the system is questionable Allow from two to five minutes for the target pressure to stabilize then convert the millitorr reading to an equivalent instrument read ing for the active measurement units Millitorr conversion factors are provided in table 9 2 in the Appendix The current calibration of the active sensor can now be checked at a number of pressure points from zero to full scale If recalibration is needed proceed with the following Setting Sensor Zero With both channels in the MEASURE mode and the output ports at about
69. nt Case The instrument case is all aluminum construction with extruded aluminum frame members and vinyl clad cover and side panels Front and rear panel assemblies attach to the case These are described separately below Front Panel The front panel figure 1 2 includes forty acter per line two line display a four by four membrane keypad and a transparent window for the pressure range label The keypad includes fif teen dual function keys plus a sixteenth key la EVCTS beled 2nd which toggles the function of the other fifteen All sixteen keys include both tactile and audible feedback Rear Panel The rear panel figure 1 3 includes access to the voltage select switch the line fuse holder the power cord socket the system power switch a ventilator fan opening and several communication connectors All of these items are grouped on the electrical module side of the rear panel The pneu matic side exposes the six fitting ports of the pres sure manifold Display Keypad a 2F 3 UNITS INHER 00008 m 2 5 Pr n MONA 5400 PRESSURE CALIBRATION SYSTEM mob Range Figure 1 2 Front Panel 110 220 V Power Power Select Switch Power Connector e Psa Pe 4 LEN IM ES
70. ntact with 9 4 Pressure Rate Limit Mode 7 3 R Rack Mount Kit 8 1 8 3 RANE T LES M d UIS h v dad 5 2 Rear Panel 2 2 1 1 1 Communication Connectors 1 2 neh 94 69 55 99 Ab w ra 1 2 Line f se Holder 4 0 ua heap os 1 2 System Power 1 2 Voltage Select 1 2 Reference Pressure 7 3 Relief Valves 5 uu estes Rex ayuu d E 8 1 Remote Operation 4 1 4 11 Resolution 7 2 Resolution eee 7 2 Response Dynamic 7 8 Response Time 7 2 SAE 2 1 7 2 iii Schematic Pneumatic 1 4 1 7 a E Sed Him ue 2 1 6 2 Services Calibration 1 7 Settling 7 3 Shipping Damage 1 1 Shock Mechanical 7 2 S Ze ae Loo a sd 7 1 Slew Speed mi ae NS ncm iw la 7 3 Software License iv Solenoid 1 6 Source Pressure 7 3 SPAM A AE 6 1 6 2 Span Drift 4ro ts 30M ow A A EO eod 7 2 Span Setting t
71. o produce two precise pressure outputs with a range of 0 1 to 100 inHga The pneumatics module is set up at the factory to use a single supply pressure source connected to either the Pt3 SUPPLY port un plugged or the Ps3 SUPPLY port plugged The EXHAUST ports are plumbed separately to accom modate two independent vacuum sources The sys tem is flexible enough that either set of ports can be reconfigured to use two supply sources and or EVCTS a single vacuum source for both exhausts if the application will tolerate such conditions While the two pneumatic channels can function independently the processor connects them digi tally The result is that pressure values for Pt3 and AP3 can be entered either from the keypad or over the communications bus and the system will re spond by generating the Pt3 and Ps3 output pres sures where Ps3 AP3 The operator can toggle the right half of the display to show either the simulated value of AP3 or the actual pressure of Ps3 HG Y OX dies Q ga LO oO ENZ TAEZ 1 HEN NO VAN Figure 1 6 Pneumatic Module Top View May 2000 MENSOR CORP EVCTS FS lt SEE NOTE 1 Q Ox 110 in Hg
72. record of the measured relationship of the instru ment output to the applied pressure over the in strument range Calibration Traceability The relationship of an instrument calibration through a specified step by step process to na tional standards or nationally accepted measure ment systems through an unbroken chain of comparisons Calibration Uncertainty The maximum calculated error in the output val ues shown in a calibration record due to causes not attributable to the instrument being calibrated Command Message See Interface Message Compensation An addition of specific materials processes or devices to counteract a known cause of error Data Message Same as Device Dependent Message DCL Device Clear A GPIB interface message used to reset the internal functions of all devices on the bus Dead Band The change through which the input to an instru ment can vary without causing a change to the instrument output Device Dependent Message A message sent from one device to another that is specific to that device to set up parameters unique to that device or to transfer data May 2000 10 1 GLOSSARY 10 2 Differential Pressure The difference between the measured pressure and a fixed reference pressure See Pressure Relation ships Drift Any change in output over a period of time which change is not a function of the pressure being measured See Stability Elevation The vertic
73. reen 9 9 9 6 Advanced CMOS Setup 5 9 9 10 1 Pressure Relationships 10 3 Tables 3 1 Keypad Functions List d dal d 3 4 3 2 Description of Menu Key Functions 3 5 42 1 Valid Sub Systems 55 4 dU EIE Es Ve M Ar RA 4 2 DL e Spare Parts List 25 Q A A h OR SUR Wed ori 5 3 7 1 Recommended Pressure at the Supply 7 4 7 2 Min Max Slew Speed 7 4 9 1 Conversion Factors psi 9 2 9 2 Conversion Factors 9 2 9 3 Temperature Conversion 9 3 9 I Meas rement Units s 3 eoe S med vL 9 4 9 5 Materials in Contact with Pressure Medium 9 4 9 6 Gas Density co A A A RUE exa sub es iem 2 9 5 9 7 Commands Queries and Default Values 9 10 MENSOR CORP May 2000 ix TABLE CONTENTS EVCTS User s Notes x May 2000 MENSOR CORP MENSOR EVCTS INTRODUCTION DID YOU GET EVERYTHING In addition to this manual you should have Engine Vane Control Test Set Power cord 1 8 inch NPT fitting adapters Any accessories ordered Envelope containing a C
74. rned in the cur rent engineering units in exponential format Outform Formats The Outform command sets the output for mat that will be returned by a subsequent out form query The formats are Outform Command Outform Query Returns 1 Pt3 Pressure Ps3 Pressure 2 Default Pt3 Pressure AP3 3 Pressure Ps3 Pressure Pt3 Rate Ps3 Rate 3442 200 MENSOR CORP EVCTS REMOTE OPERATION Command Query Set Table 4 1 Command Query Set COMMAND DATA RESPONSE FUNCTION Pt3 None Makes the left channel active Returns the left channel reading Ps3 None Makes the right channel active in Ps3 pressure mode Ps3 None Returns the right channel pressure reading dP3 None Makes the right channel active in AP3 mode dP3 None Returns the right channel AP3 reading Address 0 30 Sets the GPIB address Address None Returns the GPIB address Chan None Returns the active channel name Control None If modes are linked all channels are placed in the Control mode otherwise the active channel is placed in control Control None Returns YES if active channel is in the Control mode NO otherwise Date mm dd yy Sets the instrument date Date None Returns the instrument date Default None Sets the default values see table 3 2 Local Operation DOM None Returns the date of manufacture Error None
75. s than ambient barometric pressure See Pressure Relationships Warm up The period of time from the application of power until the instrument has reached its operating tem perature required to assure that the instrument will perform within all specified tolerances Zero Drift A change in the zero pressure output over a speci fied period of time MENSOR CORP MENSOR EVCTS INDEX A Accuracy 3 21 A A d 1 6 2 1 7 2 9 5 Adapters Fitting 1 1 2 1 7 2 Appendix 9 1 9 10 B Basic Input Output System BIOS 5 2 Battery ind TA db no eb bog by ers ns Bk 5 2 Bi Directional Pressure Control 8 1 Cable ok Se AA ad ea WR 9 6 Calculation Head Pressure 9 5 Calibration 1 7 6 1 6 2 Chath cube y PR CISE Na 1 1 Data 5554 uy ud 1 6 Environiment i 7 6 1 Medium 6 1 Pressure 6 1 Procedures oa an h 6 1 ELVICES aes eS Ses BO 1 7 Setting Sensor 6 2 Setting Sensor Zero 6 2 Cases g EI RI 1 2 8 1 iii 5 2 6 2 8 2 9 7 Certificate of Compliance 1 1 1 7 Chassis 1 6 Chassis Assembly Illustration 1 6 5 4 Cheeky System
76. ssword could be changed to the single character O for example To change either password scroll down the menus Keypad Functions List EVCTS to the appropriate password to be changed Then at the ENTER PASSWORD prompt simply enter the current master password Then at the CHOOSE A NEW PASSWORD prompt enter the digit or digits desired then press The requirement for a zero password can be turned off so that zero adjustments can be made more easily To disable the zero password requirement merely exit the CHANGE PASSWORD function by pressing 7 without entering a zero password Both the zero and master passwords were set at the factory to 123456 Again since passwords are sel dom used they are easily forgotten Please keep a written record of the latest changes as they are en tered Contact Mensor Corporation if the master password is lost Table 3 1 Keypad Functions List Function Key Sequence Description Select channel to edit 2nd F1 Toggles between and AP3 AP3 normal or Ps3 alternate display mode 2nd F2 Toggles between Normal AP3 mode and Ps3 in the right hand display Enter pressure output setpoints Use number keys to enter a setpoint use CE to back space use to execute change Changes the setpoint of the CONTROL mode output Change mode to STANDBY 2nd STBY Changes the mode to STANDBY Change mode to MEASURE 2nd MEAS
77. sure to allow the proper spacing above and below the EVCTS An EVCTS with the rack mount option is then installed from the front of the rack Before installing the EVCTS remove the four feet from the bottom of the instrument Slide the EVCTS all the way into posi tion and secure the instrument to the rack before connecting power and pneumatic lines to the rear panel Figure 8 1 Transport Case D p 60 p D MENSOR CORP May 2000 OPTIONS EVCTS After all equipment is installed check to see that CAUTION MOTORS OR VIBRATING DEVICES the temperature inside the rack does not exceed SHOULD BE MOUNTED SO AS TO MINIMIZE 38 C If it does additional rack spacing and or THE VIBRATIONS AT THE EVCTS ventilation must be considered Front View 7 A 9 gt 7 amp 6 97 17 70 gt ka 3 amp 5 25 a RW El 13 34 cm DARA 2 pes 400 PRESSURE CALIBRATION SYSTEM Pario igh APS 100 ie Y 86 x 2 18 cm lt 17 05 43 31 cm gt lt 19 00 48 26 cm gt Side View Slide Member O O O A 2 30 V 5 84 cm M Y lt 20 00 50 80 cm gt Figure 8 2 Rack Mount Dimensions 8 2 May 2000 MENSOR CORP EVCTS OPTIONS 19 48 26 cm RACK WIDTH RACK WITH STANDARD RETMA MOUNTING HOLE PATTERN ONE RETMA SPACE 1
78. t of pressure experience PRODUCTS Mensor s portfolio of products consists of an extensive line of precision pressure instruments including digital gauges pressure controllers transducers and pressure calibra tions systems All of these products feature computer interface capability These products are used in metrology labs calibration labs research facilities engineering offices production test stands and in other environments were high accuracy pressure measurement and or control is required Many of these products include customized features to meet a customer s specific requirement Mensor products range from about 900 to 30 000 CUSTOMERS Typical Mensor customers are pressure sensor manufacturers aerospace firms jet engine manufacturers electric utilities nuclear power plants pharmaceutical firms calibra tion laboratories government agencies and research organizations APPLICATIONS In many facilities the highest accuracy pressure measuring or pressure controlling instrument is a Mensor product A typical application for these Mensor instruments is the calibration of other pressure devices such as sensors transducers transmitters gauges and pressure switches The Mensor product is used as the pressure standard to verify pressure calibrations or outputs of the device being produced checked tested or certified MENSOR CORP May 2000 User s Notes EVCTS vi May
79. tandby None Returns YES if active channel is in the Standby mode NO otherwise Step within lower Sets the control step for the active channel in the current pressure units Must and upper be less than or equal to the sensor range limits Step None Returns the control step for the active channel Time hh mm ss Sets the instrument time Time None Returns the instrument time Units psi inHg Sets the instrument engineering units inH2O mbar kpa mmhg or PCS 400 unit code Units None Returns the instrument engineering units UpperLimit within sensor Sets the upper control limit for the active channel range and more than lower limit UpperLimit None Returns upper control limit for active channel Continued on next page May 2000 MENSOR CORP EVCTS Table 4 1 continued REMOTE OPERATION COMMAND DATA RESPONSE FUNCTION Vent None If modes are linked all channels are placed in the vent mode otherwise the active channel is placed in Vent Vent None Returns YES if active channel is in the Vent mode NO otherwise Window within lower Sets the measured reading exponential filter window for all channels This and upper is a pressure value that the measured pressure must be within for the filter limits to be applied No filtering is applied to pressure readings when the measured pressure is outside of the set window Window None Returns the filter wi
80. ter this mode to change the current zero or master password or to disable the zero password require ment More information is given on pass words later in this section TEST LIMITS May 2000 EVCTS Enter the TEST menu area to enable the various sub menu tests available Press or repeatedly to step through the various sub menus listed below ex haust supply etc To enable a specific test press 7 while the test is showing in the display EXHAUST Tests for a vacuum on the Exhaust port of the current channel A vacuum is required to control sub at mospheric output pressure The display will show a fail message for the test if it measures a vacuum pressure greater than 1 one inHgA SUPPLY Tests for source pressure great enough to provide a controlled output pressure near the span of the selected channel A Pass or Fail message is sent to the display SENSOR Tests the communication link between the electrical module and the pressure sensors in the pneumatics module The test returns a Pass or Fail message CONTROL VALVES Tests for media flow through the pressure controller valves A Pass or Fail message is sent to the display PNEUMATICS Tests the actuating coils of the solenoid valves The test sends a Pass or Fail message to the display The LIMITS menu provides access to three sub menus Press or repeat edly to step through the sub menus Press to access a sub menu
81. ty and accuracy excessive motor or machinery vibration of the mounting sur face should be avoided PRESSURE CONNECTIONS NOTE When making up the connection to an o ring adapter use a back up wrench to prevent over stressing the threads in the manifold block All of the pressure ports on the rear are female 7 16 20 SAE MS straight threads per MS16142 and SAE J514 table 14 They require a tube fitting boss seal with an o ring per MS33656 Mensor provides female 1 8 NPT adapter fittings with the instru ment The pressure connections can be made to these adapters with the proper mating hardware We recommend the use of either Loctite Hydraulic Sealant or fresh teflon tape on the threads of the male pipe fitting Do not use sealants on fittings sealed with an o ring The integrity of the seal is particularly important since even microscopic leaks can cause errors in pressure measurements Figure 1 7 is a pneumatic schematic of the internal plumbing Requirements for connecting to the vari ous ports the EVCTS manifold are given below SUPPLY Pressure Port Each channel of the EVCTS has its own SUPPLY port However one of these is plugged on the rear panel since they are connected together inside the pneumatics module Connect a source pressure of 55 to 60 psi 110 120 inHg to the open SUPPLY port EXHAUST Pressure Ports Connect a separate vacuum pump to each of the two EXHAUST ports These ports must be evacu ated in
82. x or less except Oa hex Normally an ASCII space 20 hex 32 dec is used for the field separator Lower case letters are converted to uppercase by the EVCTS and may be used to improve readability Command Query Field Unless otherwise speci fied commands are converted to queries by ap pending a question mark to the command Detailed command and query functions are listed in table 4 1 Data Field The data field is either an ASCII string or numeric value The data field is only used with commands not with queries If the data field is omitted in a command the default value is used In the case of multiple data fields commas are used to separate the fields String or numeric data are acceptable in any of the following formats Example ASCII string data ON OFF mBar inHg May 2000 REMOTE OPERATION EVCTS Example ASCII numeric data 1 1 0 5 678 25 68324e 5 Command Set Definitions White Space any character code lt hex 0x20 space except hex lt lf gt Command any valid command listed below Data ASCII representations of numeric or string data Termination hex 1f Commands are always sent in one of the follow ing formats Command Termination Command White Space Data Termination Queries are special commands that contain the character Queries always return an ASCII data string termi nated with cr lf Floating point data is always retu
83. y discharged it is not necessary to apply power to the unit before replacement begin at step 2 below lb If the battery is still functioning first apply power to the electrical module This will hold the CMOS data in RAM while the battery is out of the circuit CAUTION HIGH VOLTAGE IS PRE SENT IN THE VICINITY OF THE POWER INPUT CONNECTOR 2 Before disconnecting the battery note the location and orientation of its connector by making a sketch of the pin numbers and wire colors in relation to the battery and terminals 3 Disconnect the battery connector and re move the battery connector assembly from the module 4 Confirm that replacement battery is same voltage as the removed battery 5 Pay attention to the and sides of the two batteries and install the connector and wir ing on the new battery to match the old battery 6 Connect the battery connector to the mother board in the same orientation as when it was removed 7 Cycle the power off then back on The system should initialize the same as it normally does If the system hangs up with a cursor in the upper left corner of the display first check that the system disk is seated in the disk drive If the system disk is in place then refer to the CMOS Setup instruc tions in the Appendix Section 9 MENSOR CORP EVCTS MAINTENANCE SPARE PARTS LIST Below is a table showing EVCTS spare parts that can be ordered from Mensor
84. y enter the valves and prevent proper operations Servicing the valves by the user is not recommended TRANSPORT CASE PN 0011159001 A wheeled Transport Case is available suitable for moving the EVCTS between sites or as an air freight or other shipping container The case is constructed of a high impact plastic with a silver grey exterior It includes two keys locks a piano hinge an anodized interlocking tongue and groove Fold out Handle Wheels OPTIONS opening with a 90 degree stop various nickel chrome and stainless steel fixtures a vinyl satchel style handle and a fold out metal push handle with a vinyl grip The interior is filled with high density polyurethane foam with a die cut cavity to cradle the instrument with fitting adapters in place and an additional cavity to store related accesso ries Rugged and weather resistant the case makes an attractive practical shipping and moving con tainer The case weighs approximately 29 pounds 13 15 kg unloaded and can support a load of up to 150 pounds 68 04 kg Nominal dimensions are 15 inches by 24 inches by 26 inches 38 10 cm x 60 96 cm x 66 04 RACK MOUNT KIT The EVCTS is easily mounted into a 7 inch opening ofa 19 inch wide rack The rack used should satisfy the dimensional requirements shown below It should be free of vibration and excessive heat as noted below Install the chassis slide being

PRECISION INSTRUMENTS & SYSTEMS

Contents

Download Pdf Manuals

Related Search

Related Contents

PRECISION INSTRUMENTS &amp; SYSTEMS

Contents

Download Pdf Manuals

Related Search

Related Contents

PRECISION INSTRUMENTS & SYSTEMS