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MODEL 2465A-754 USER`S MANUAL

1. 24 w co gms 49 8000 waw L L ms 3 G GO Z 9 196 d 4 P o 125 N S NOLOSNNOO S W Z TIVIDId WONT SAING MID 6 LA NId NOIDSNNOO S W 2 TIVIDId HOYA TAIYA MO BLIHM zz 91 OT NId HOLOSNNOO S W Z TIVIDId HOYA OND NMOWA JON amp Nova HOL04NNOJ YOSNAS WOLDANNOD GITAHS OSNES EEG ETTE N WAINAJ HOLOANNOD QVdHXIDS 44 TVNDIS YOSNES di tel O a TYNDIS rz CIVIXVOO NOILISOd 1VO 13 4 NId NOIOSNNOO S W F NId MOSNES NOIIVION 104 be E cen dd TF RIG 78 WOT VET e TYNDIS Z NId YOLDANNOJ S W Z NId HOSNSS NOIIVION 108 Szar rz 3E GF NId WOLDANNOD 57 Nid WOSNES NOIIVIOH ast 72 m U Z NIA SEM SEM NOIIV2OT NOIIV2OT NOTTONNA 79 d AL 0333 as ZA RIS 2 NOIIVNIWHSI 1 NOILYNIWYAL ANNIVA Z NIA 4 y zem TEM
2. a NA N Ge R P 41795 JIA 1935 Ss ek 2 z _ 5 7 Y 9 7 5 22 28 KAIK 9 3 CJ CA y NN i ch 197 ug I 10 2 6 189 22922 casess 617 Ole 539 Love d 804 10 2 8 188 ovozz 000 oasa V S3ONVS31IOL NOLVOISSVJ mo pm 131412145 3SIMHIHLO SSJINN 80938 NOISIA3 A B 8 DRAWINGS amp BOM s BILL OF MATERIAL 2465 729 PISTON CYLINDER ASSEMBLY HIGH RANGE 1 KSI NO ITEM NUMBER 0006 2460 6 1 CNTNR CYL APG 1 000 EACH 0007 2470 6 158 R RTNG MASS 0158 GRAMS 6 000 EACH 2460 6 7 R RTNG MASS 0154 0164 GRAMS 6 000 EACH 0008 2460 6 2 RETAINER CYL TILTG PISTON DWG 1 000 EACH 0009 54 703 113 552IDx 104 75DURO FKM 4 000 EACH 0010 61 709 PLGR W15 N 1 000 EACH 0011 2465 100 AIR PAGE P CYL CLEANING KIT 1 000 EACH B 9 DRAWINGS amp BOM s pP TAE uu ew iod NIS LO ww 11 4 SANGRE Da Haan ON Tire 12451 i wa 33 z WH eS BIS F LVH Deere as 20 leva 5 a SIOK
3. FIGURE 2 1 FIGURE 2 2 FIGURE 2 5 SIMPIF CYLINDFR RE ENTRANT CYLINDER CONTROLLED CLEARANCE CYLINDER When the simple cylinder of Figure 2 1 is subjected to an increase in pressure the fluid exerting a relatively large total force normal to the surface of confinement expands the cylinder and thus increases its area A pressure drop appears across the cylinder wall near pointA resulting in an elastic dilation of the cylinder bore It can be shown that the effective area of the piston and cylinder assembly is the mean of the individual areas of the piston and of the cylinder therefore as the pressure is increased the cylinder expands and the effective area becomes greater The rate of increase is usually but not always a linear function of the applied pressure The piston also suffers distortion from the end loading effects and from the pressure of the fluid but to a much lesser extent than the cylinder It is evident then that the simple cylinder of Figure 2 1 would be inadequate for a primary piston pressure gage unless some means of predicting the change in area were available The increase in the effective area of the simple cylinder is also accompanied by an increase in the leakage of the fluid past the piston Indeed the leakage becomes so great at some pressures that insufficient floating time can be maintained for a proper pressure measurement In Figure 2 2 the pressure fluid is allowed to surround the body of t
4. TOWINOD ZY D 22 92 55 dO ONY 89 8 OINI LHJSN THS TEX 5 9 5 go oe t ONY 219 28 Lu3SN Du 4 TK TIVISId S TMS 240 8T 6 y ra 7 5 6 7 RW STI V7 8118 96 TT 066 08 OIN L4JSNI y W E TMS 6 01 275 I T JBVMONVH TN HOVLIV OL NOONJA W 8 NOION TL TIVIDIA TL 8 11 ara y 8 SNIENL ANIHES 1V3H 11 93409 Y E Z Nid dWVT W TIVIDId 8 11 ma 8T 9992 06 D NOLLYTASNI A009 SLOL IN Yad 33M Y 9 NI VF TIVISIA 5 THM 8T 5 18 355 1 4 NI O3TIVISNI NS 0 s ST X7 gwa 5 1 2 Ma Ee 400 51 99 X F 5 IATNI WALTIA TH TIVIDIA 8T 9502 76 v O da ONY TIWLSId ATA 81 72 4195 76 3A31 H3BWON 99 wv z x 7 TF TIVIDId MA Ty 9697 06 z AO ONY 699 8 OIN LH4SN E ISINI HSITI4 Ti TIVISId TTL 385 BT STIE 56 T dWI4O ONY 099 208 OLNI 133SN WV NOTLWOOT NOIIV2OT NOIIV2OT osaa 0705 RE OIN SHIM ANIEHS ONY 39105 V AI8W3SSV GT NI 2 NOIIVNIWNSI AONAWAJHH HO4 NMOHS S00 ST Ti NOIIVNIWHSI SSSNNVH NOIIVNIWHSI G 9 1 DRAWINGS amp 5 BILL OF MATERIAL 2465 23 KIT L
5. atv ad HOLD n3 wm 33 SLEW Pause 1 Wey DY ZEE a Lid dw TG LIG TA W 5 Ux 033213 Lon H2W3 LE 37382 F s r 761 SHJGWNN 32430935 WALI xxx Zei EB uen y aa HEG 55 2 07 F D B 18 DRAWINGS amp BOM S BILL OF MATERIAL 2465 14 ASSY VAC SEAL ITEM NUMBER 54 703 10 O RING VITON 1 4 X 1 16 X SEC 1 000 19 DRAWINGS amp 5 2507 43 Ly EGW OH Die Sowa FG LBG ATWO Hind 62473233 LOM TNMG MOWA RL Boa HIIHTI Z61 43 Wad SIDUIWWd e 20 DRAWINGS amp 5 BILL OF MATERIAL 2465 15 MOTOR CASE SUB ASSY ITEM NUMBER 2465 15 003 SWITCH MOUNTING PLATE 1 000 26 222 FUSE S BLO 1 4A LITTLEFUSE 2 000 2465 15 002 COVER BACK MO TOR CASE 1 000 LEVEL VIAL CIRC 1 44 DIA 20 MIN 1 000 E 47 399 259 2 MO TORGEAR REDUCED 52 RPM BODI 1 000 53 306 901 NUT 8 32 STAINLESS STEEL PERA 7 000 63 295 PULLEY A D DAE13 PRCN 1 000 EA ____ FEOYESSESI EA 2 E E CET BA 0 F d F EA LEA 0 F EA F EA 0 EA BA 0 F 0 EA E E EA EA EA EA EA EA EA EA EA EA EA EA EA EA EA EA EA EA EA EA EA
6. HINOLSNI AG Q31HA3SSV MANISSY SIHL 30 LON 34 ONY AINO NOLIYAHO 23 NMOHS 359 008 59 0 ONY 7G VG9vZ lt 2061 93 934 53010 ONY 530 71 10 SSJINN S310N DRAWINGS amp 5 27 THIS PAGE INTENTIONALLY LEFT BLANK DRAWINGS amp 5 B 28
7. V INTRODUCTION WARNING PRESSURIZED VESSELS AND ASSOCIATED EQUIPMENT ARE POTENTIALLY DANGEROUS THE APPARATUS DESCRIBED IN THIS MANUAL SHOULD BE OPERATED ONLY BY PERSONNEL TRAINED IN PROCEDURES THAT WILL ASSURE SAFETY TO THEMSELVES TO OTHERS AND TO THE EQUIPMENT DO NOT USE OXYGEN AS THE PRESSURE SUPPLY MEDIA USE ONLY DRY CLEAN NITROGEN DO NOT EXCEED SAFE MAXIMUM INLET PRESSURES AS FOLLOWS WITH LOW RANGE PISTON CYLINDER 40 PSIA POUNDS PER SQ UARE INCH ABSO LUTE WITH MID RANGE PISTO N CYLIN DER 115 PSIA WITH MID HIGH RANGE PISTO N CYLIN DER 515 PSIA WITH HIGH RANGE PISTO N CYLIN DER 1015 PSIA DO NOT USE HYDRO CARBON LUBRICANTS USE ONLY RUSKA INSTRUMENT CORPORATION SUPPLIED LUBRICANT PART NUMBER 45 339 UNLESS O THERWISE SPECIFIED IN THIS MANUAL ALWAYS USE REPLACEMENT PARTS SPECIFIED BY RUSKA INSTRUMENT RPO RATION WHEN ANY MAINTENANCE IS PERFO RMED TURN OFF POWER AND REMO VE POWER CORD vi INTRODUCTION OXYGEN COMPATIBILITY This instrument has been designed with components that will not introduce hydrocarbons into the calibration process The O ring and lubricating grease supplied with the instrument must not be substituted with other laboratory supplies Cleaning of the instrument for oxygen compatibility using liquid Freon and ultrasonic cleaning systems is permitted with the EXCEPTION OF THE PISTONS AND CYLINDERS The Ruska procedures for piston cylinder cleaning as described in Section 6 0 of this
8. NESSZZE Lyge UJWOLSNO A8 0319915 NOILOANNOD ANNA NO44 12 1414 31 349 AINO 04 N 7 39393333 WNNOWA 9 866 A 404 4 TVNOLLIQOV S GIOAY OL I 3905 SLI NO 38 OL lt OHS HINOISNI Q318A3SSV AIGINASSY SIHL 30 1394 A JYV X0C VG9vC ONIGNL IN 7 61 43 Hdd 530 SJONVYITOL NOLLVOISE 7431519395 ISIMAIHLO SSTINN vil 310N B 26 DRAWINGS amp BOM S las SJTIOBINOJ VONVA 008 5972 P 5 TYNNYN 0319915 YINOL B 8 98 ind Aladhs 531 434 55389 OWA ave 1531 Mad TTS x UM Ne PNE 857 66 m 130 301911934 dans HINOLSNI Q3ridans 5 lt N NOWdO HNNJVA 09 9 866 Aldd ANNIVA E 8201 8 9 866 1 9 866 804 TVNOLLIAAV lt GATYA JONIUIIYUILNI OL 30145 SLI 38 01 mva lt
9. after every six weeks of operation Replace the O Rings if leakage occurs in the gage To lubricate and replace the O Ring Rotary Seal on the Cylinder Housing remove the two Shoulder Screws 71 103 and pull the entire O Ring holder from the gage body Unscrew the Packing Nut 2460 4 15 and lubricate and replace the O Ring Install the O Ring by reversing the above steps Refer to the drawings in Appendix To lubricate and replace the drive gear shaft O Ring seal or to lubricate the drive gears remove the two hex head screws that hold the Gear Support 2460 4 19 in the gage body Loosen the screw that holds the Hub Clamp 13 485 on the drive gear shaft and remove the Hub Clamp The drive gear shaft with the drive gear permanently attached can then be pulled from the Gear Support After removing the Ball Bearings 5 144 the Vacuum Seal 2465 14 can be pushed out of the Gear Support Unscrew the Packing Nut and lubricate or replace the O Ring Before replacing this unit in the gage the drive gears should be lubricated with a mixture of Dupont Krytox 240 AA Grease 45 339 and OPERATION 5 4 molybdenum disulfide The Vacuum Seal 2460 14 Packing Nut and O Rings need not be installed in the Gear Support 2460 4 19 unless a vacuum reference pressure is being used for absolute pressure measurements The Ball Bearings 5 144 should be cleaned and lubricated with one drop of DuPont Krytox 143 AZ Fluorinated O il whenever the gage is
10. 2 5 CONSIDERATIONS method of observing The precision of the comparison will depend directly upon the ability of the operator to judge the degree to which the balance is complete This procedure is repeated for several pressures and the values of areas obtained are plotted against the nominal pressure for each point A least squares line is fitted to the plots as the best estimate value of the area at any pressure Of the different methods used in amplifying the signals that are generated by the crossfloat process one is presently in use that is rapid and convenient An electronic sensor which indicates the floating position of the piston is placed beneath the masses of each gage The output signal from the sensor is processed and fed to an analog meter having a vertical scale the value of which is adjusted to indicate units of displacement of the piston Two meters one for each instrument are placed contiguously for simultaneous viewing A constant volume valve inserted between the gages supplements the sensors Other less precise methods of estimating the true balance include a Optical amplification of the sinking stack of masses of one of the gages while timing the descent with a stop watch and b Interposition of a sensitive null pressure transducer which displays small pressure differences directly When using a suitable amplifying device the scatter in the plotted areas from a good quality piston gage should not exceed a
11. 3 FIGURE 6 4 FIGURE 6 5 FIGURE 6 6 FIGURE 6 7 FIGURE 6 8 FIGURE 6 9 FIGURE 6 10 FIGURE 6 11 FIGURE 6 12 FIGURE 6 13 FIGURE 6 14 TABLE A 1 TABLE A 2 TABLE A 3 TABLE A 4 LIST OF FIGURES AND TABLES SIMPLECYHNDER Guan 2 1 CYLINDER ate ett hn nets 2 1 CONTROLLED CLEARANCE 2 1 GAS LUBRICATED PISTON PRESSURE GAGE 3 3 GAS LUBRICATED PISTON PRESSURE GAGE 3 5 STACK UP F R PISTON PERATIO o ee 5 6 PARTS REQUIRED FOR LOW RANGE PISTON OPERATION 5 7 REMOMNG LOW RANGE PISTO N AND CYLINDER FRO M CONTAINER 5 9 REMOMNG LOW RANGE PISTO N AND CYLINDER FRO M CONTAINER 5 9 HANDLING LOW RANGE PISTON AND CYLINDER 5 11 LOW RANGE PISTON AND CYLINDER SHO WING O RING GROOVE 5 11 POSITIO NING THE UPPER THRUST WASHER PISTO N RETAINER IN THE CYLINDER RETAINING CAP 5 13 PARTS REQUIRED FOR PERATION OF THE MID RANGE P C 5 15 MID RANGE PISTO N CYLINDER 5 17 RETAINING NUT AND BEARING 5 17 PARTS REQUIRED FOR RANGE PISTON OPERATION 5 19 PARTS REQ UIRED FOR OPERATION OF THE 35 BAR 5 21 MATERIALS FOR CLEANING LOW
12. LEFT BLANK OPERATION 5 16 TV me EX y FIGURE 5 8 MID RANGE PISTON CYLIN DER ASSEMBLY Upper Thrust Bearing 2460 21 Retaining Nut Thrust Block RETAINING NUT AND BEARING FIGURE 5 9 5 17 OPERATION THIS PAGE INTENTIO NALLY LEFT BLANK OPERATION 5 18 Lower Thrust Cylinder Container Bearing 2460 6 1 2460 4 25 Piston Cylinder not required with Assembly this P C but may remain in base O Ring Filter Retainer 54 703 113 2460 4 27 Cylinder Retainer 2460 6 2 O Ring 54 703 119 FIGURE 5 10 PARTS REQUIRED FORHIGH RANGE PISTON OPERATION 5 19 OPERATION THIS PAGE INTENTIONALLY LEFT BLANK OPERATION 5 20 Lower Thrust Bearing 2460 4 25 not required with this P C but may remain in base Cylinder Container 2465 730 3 Piston Cylinder Assembly O Ring Filter 54 703 119 Retainer 2460 4 27 Cylinder Retainer 2465 730 4 FIGURE 5 11 PARTS REQUIRED FOR OPERATION OF THE 35 BAR 5 21 OPERATION THIS PAGE INTENTIONALLY LEFT BLANK OPERATION 5 22 SECTION 6 0 PISTON CYLINDER CLEANING INSTRUCTIONS 6 1 GENERALINFORMATION AND PREPARATION When it is necessary to clean the Piston Cylinder Assembly the Piston Pressure Gage must be partially disassembled and some of the components set aside until later Upon removal of the internal components a degree of risk is involved because of the possibility of exposing the parts to harmful dirt corrosive fingerprints and being dropped
13. M apparent mass record in Column 9 F force required on piston as found in Column 8 K multiplier which was determined by previous equation FOR SI UNITS K 1 lg 1 rr where 2 acceleration due to local gravity in m sec density of air in g cm see Equation A 4 air density of apparent mass am CALCULATIONS A 2 for Apparent Mass versus Brass 8 4 g cm for Apparent Mass versus Stainless Steel 8 0 g cm When selecting masses from the calibration report assure that the values selected are in same Apparent Mass unit of measure that was used to calculate the values The apparent mass Column 9 is obtained from M FK where M apparent mass versus brass record in Column 9 F force required on piston as found in Column 8 multiplier which was obtained by previous equation When the masses are applied to the piston in an evacuated bell jar the above equations for can still be used this situation the density of air will be zero which will cause the buoyancy portion of the equation to become 1 Also the results will indicate the quantity of mass not apparent mass that must be applied to the piston Column 1 is the desired pressure at the reference plane of the device being calibrated F Column 2 is the mass density of the pressure medium being used in the piston pressure gauge system For hydraulic piston pressure gauges this numb
14. RANGE PISTON CYUNDER 6 7 PREPARATIO NS FOR CLEANING THE LOW RANGE CYLINDER 6 7 PREPARING THE KIM WIPES 6 9 PREPARING THE KIM WIPES 2 nn ee ee 6 9 PREPARING THE LOW RANGE CLEANING 6 11 PREPARING THE LOW RANGE CLEANING TOOL 6 11 MATERIALS FOR CLEANING MID RANGE PISTO N CYLINDER 6 13 PREPARING THE MID RANGE CLEANING 6 13 MATERIALS FOR CLEANING HIGH RANGE PISTO N CYLINDER 6 15 PREPARING KIM WIPES FO CLEANING HIGH RANGE CYLINDER 6 15 PREPARING KIM WIPES FO R CLEANING HIGH RANGE CYLINDER 6 17 PREPARING KIM WIPES FO R CLEANING HIGH RANGE CYLINDER 6 17 CLEANING THE HIGH RANGE 6 19 DRYING THE HIGH RANGE 6 19 CONVERSION FACTORS aa w a ae aqha A 7 STANDARD PRESSURES FOR PISTO PRESSURE GAGE ENGLISH A 2 STANDARD PRESSURES FOR PISTO PRESSURE GAGE 9 A 2 AIR DENSITY A ala A 6 X INTRODUCTION 1 1 SPECIFICATIONS LO W RANGE PISTON Pressure Range Model 2465 Pressure Range Model 2468 Pressure Uncertainty Rating Uncertainty Threshold Resolution Precision Typical Type A Unc Long Term Stability Piston Cylinder Materia
15. disassembled WARNING Do NOT lubricate the lower thrust bearing 2460 4 25 or the upper thrust bearing 2460 5 6 See Drawing Number 2465 725 in Appendix B If either of these bearings is dirty or oily clean them before using To clean these bearings rinse them with a solvent such as acetone or high grade alcohol Dry tnem thoroughly before installing them Should it ever become necessary to replace the power fuses the fuse holders are located in power in receptacle on the side of the Motor Case Assembly 2465 15 These fuse holders are located inside the cavity above the three power receptacle prongs Disconnect the power cord from the wall power receptacle and from the Piston Pressure Gage s power in receptacle Use a small flat blade screwdriver to pry the voltage select fuse holder compartment door out from the power in receptacle Both the fuses should be checked and replaced if necessary with fuses of the correct value depending 115 VAC or 230 VAC local power supply conditions Replace fuses only with the 3AG Slo blo 1 4 Amp fuse Ruska part 26 222 To replace the fuse holders simply push them back into the receptacle so that they snap back into place Then close the compartment door making sure that the correct voltage is showing through the small window the correct voltage is not displayed through the window pry open the door again Remove the voltage select wheel turn it to the correct value and replace it with
16. few parts per million CONSIDERATIONS 2 6 2 9 10 11 12 BIBLIOGRAPHY Bridgman W The Physics of High Pressure Bell amp Sons London 1952 Cross L Reduction of Data for Piston Gage Pressure Measurements NBS Monograph 65 1963 Dadson R S The Accurate Measurement of High Pressures and the Precise Calibration of Pressure Balances Proc Conf Thermodynamic and Transport Properties of Fluids London pp 32 42 1957 Institute of Mechanical Engineers Design and Test of Standards of Mass NBS Circular No 3 Dec 1918 Included in NBS Handbook 77 Volume Ill Johnson D P J L Cross D Hill and A Bowman Elastic distortion Error in the Dead Weight Piston Gage Ind Engineering Chem 40 2046 Dec 1957 Johnson D P and D H Newhall The Piston Gage is a Precise Measuring Instrument Trans of ASME April 1953 Newhall D Abbot Controlled Clearance Piston Gage Measurements and Data Jan Feb 1970 Pressure Measurement Measurements amp Data Home Study Course 17 Measurements and Data September O ctober 1969 Tate D R Gravity Measurements and the Standards Laboratory National Bureau of Standards Technical Note No 491 1969 Heydemann and Welch Chapter 4 Part 3 Pure and Applied Chemistry Butterworths Kirk K Mosher Ruska Instrument Corporation The Traceability Chain of the
17. has been maintained or to the completeness by which corrections were applied for these factors Elastic distortions of the piston and cylinder Effects of gravity on the masses Temperature of the piston and cylinder Buoyant effect of the atmosphere upon the masses Hydraulic and gaseous pressure gradients within the apparatus Surface tension effects of the liquids The Ruska Instrument system uses the RE ENTRANT type piston pressure gage CONSIDERATIONS 2 2 2 2 MEASUREMENT OF PRESSURE WITH THE PISTON PRESSURE GAGE Pressure results from the application of a force onto an area Numerically it is the quotient of the force divided by the area onto which it is applied P F A where P represents the pressure F the force and A the area 2 3 ELASTIC DISTORTION OF THE CYLINDER As the pressure is increased within a piston pressure gage the resulting stress produces a temporary and reversible deformation of the cylinder The net effect is a change in the effective area of the piston cylinder assembly The change in the area is described by the equality A A 1 b P b where A effective area ata pressure P A area of the piston cylinder assembly at a reference pressure level and b and b are coefficients of elastic distortion which are determined experimentally 2 4 GRAVITY Since pressure is defined as force per unit area anything that changes the force applied to the piston of a piston pressure gage also
18. manual must be followed ULTRASONIC CLEANING MAY DAMAGE THE CRYSTALLINE STRUCTURE OF THE TUNGSTEN CARBIDE PISTO NS AND CYLINDERS Vii INTRODUCTION TABLE OF CONTENTS WABRAN pem 11 COPYRIGHT NOTICE DISCLAIMER TRADEMARK iii REVISION NOTICE eu Gb O pas iv REVISION HISTO exierit bea cua ceteri AK V WARNING sects aia OXYGEN CO MIPATIBMATY aa TABLE OF CONTENTS ane UST OF FIGURES AND TABLES aaa id X SECTION 1 0 SPECIFICATIONS 151 SPECIFICATION ccc 1 1 SECTION 2 0 GENERAL PISTON PRESSURE GAGE CONSIDERATIONS 2 1 TYPES OF PISTON PRESSURE GAG xs ona 2 1 2 2 MEASUREMENT OF PRESSURE WITH THE PISTO N PRESSURE 2 3 2 3 ELASTIC DISTORTION 222222524 c 2 3 24 Sr aa 2 3 2 5 BUOYANT EFFECT OF THE AR a 2 3 2 6 TEMPERATURE OKAZ lo m AKA 2 4 2 7 REFERENCE PLANE OF MEASUREMENT nt E 2 4 29 SSELOATNG 2 5 2 9 BBLIOG BA PRY lll 2 7 SECTION 3 0 DESCRIPTION 3 1 GENERAL INFORMATION was ee 3 1 3 2 DESCRIPTION THE MASS SET ea 3 1 SECTION 4 0 INSTALLATION AXE INSTALLATION awa lada 4 1 SECTION 5 0 OPERATION 5 1 PRECAUNT
19. 0 TO 6 9 MPa To calculate the density of Nitrogen at pressures from 0 01 MPa gauge to 6 9 MPa use the following equation DENSITY kg m 1 585 E 06 xP where PRESSURE in Pa absolute if P is gauge convert it to Pa absolute by adding barometric pressure e g P 101325 HELIUM DENSITY SI UNITS 6 9 MPa TO 100 MPa To calculate the density of Nitrogen at pressures from 6 9 MPa gauge to 100 MPa use the following equation DENSITY kg m 0 3136 E 01 1 508 P 3 886 E 03 P where P PRESSURE in MPa absolute if P is in gauge convert it to MPa absolute by adding barometric pressure e g P 0 101325 TABLE A 1 CONVERSION FACTORS TO CONVERT FROM MULTIPLY BY Pa N m 1 N m Pa 1 Pa MPa 10 MPa Pa 10 N m MPa 10 MPa N m 10 Pa PSI 1 450377 10 6894 76 MPa PSI 145 0377 PSI MPa 6 89476 X 10 where Pa pascal MPa megapascal N newton m meter PSI pounds per square inch A 7 CALCULATIONS THIS PAGE INTENTIONALLY LEFT BLANK CALCULATIONS A 8 PISTON PRESSURE GAUGE PRESSURE CALCULATION WORKSHEET ENGLISH UNITS RUSKA Date Expected Temperature t Reference Plane Difference h inch 1 c t 23 C inch Mass Set Serial No Local Gravity g cm sec Piston Serial No Air Density Fa g cm Ib in Ao at 23 C inch Gravity 8 Buoyancy bi psi Tare Apparent Mass pound bo Ipsi Reference Pressure mtorr psi Tem
20. 000 E A EA 24 649 FTG FILTER DISC 1 000 2460 1 37 INSERT SCREW TLTG PSTN GAGE 2 000 EA EA EA EA 2460 66 SCREW ASSY LEVELING ADJUSTABLE FO O T 2 000 EA EA EA EA EA 25 64 FTG PLUG 1 8 NPT HEX HEA SO C STEEL BLACK 1 000 EA BACK FNS 24 650 FTG VENT BREATHER 1 8 M40MU ASP 1 1 000 EA BV A A A A A A A A B 13 DRAWINGS amp BOM s ITEM NUMBER 25 744 RETAINER 1 4 FTG 402 61 F 1 000 EA 31 13 _________ SNAP 5 16 ID X7 16 HEYCO 58 437 5 1 000 45 339 7 GREASEFLUORINATED 35CS 202 000 FA 53 965 7 NUTKNRL 188TBG BR 1000 54 700 22 O RINGBUNANIXI 6 1000 EA 54 700 239 DRIVE BELT SEE SPEC PARKER DBA 2 239 E751 65 EA EA EA EA EA EA 70 147 2100 SCREWSHCS8 32X1 14ST 4000 EA 82 424 TAPE TEFLON 1 4 IN X520 FT 3 5 MIL 5 0 500 EA PP EA EA EA EA EA LABEL METALIZED PO LYESTER 1 38 X 2 65 99251 LABELCESTAMP 1100 E 86 790 TUBING 50 1 4 X 032 WALL 0 750 88 802 VALVE METERING B SM 2 S2 A NPTM SWG 1 000 E E E E A EA A EA A A EA EA A EA A EA A T A A A A A EA 2465 6 Mercury in Glass Thermometer Assembly is no longer standard It is now option which must be purchased separately 2465 6 is not NAVLA
21. 19 O RING 15 16 X 3 32 70 DURO BUN 4 000 2465 100 AIR PAGE P CYL CLEANING KIT 1 000 2465 730 4 CYLIN DER RETAIN ER 1 000 B 7 DRAWINGS amp BOM s L 30113345 OMO 19689700 my nu 31498 1074 awas WAC Em N 325 ONINV3TO uva 10 2 8 03810 JIBISNOdSIU 10 2 8 OTBBWO 4 030389 NOLWANDENI 133 5 SHL 2901 ONIMYGG 31405 LON OG 00 LL OTAGO d 3100 SVX3L NOLSMOH NOLLY2OdHOO LNINNSLSNI 1902 G394538 SV Q3IHORAdO3 3508 une 83810 ANY 304 SMUMID OL 35070 03SN 38 OL JON SI 3804479 GALINT Y 404 O3 SN und SI 0 INGNTMISN 40 MINGLNOO SI SJHONI NI SNOISN3MIG 131412345 5 SJINN 5938 wo Rh pa 3 Jdv ddddv1 199 SvHOM d MVH MNYTE Liz SE HJONIIAO YINIVINOO ASSY ONIHVJE 134 SJGNIIAD NOISId ave S AYL S X WUE X Tya 0 38 asx ZE E X 91 6 N YNNE ONIY O 611 004 786 O3SX 91 1 X 91 6 N YNNE ONH O GL 004 vG le 61 7006 754 89 6
22. DRAWINGS amp BOM s BO 5 AG A LADO DL usv NIC AR 19 GL Fin Fad SZ RON WDH HOLLIS KOL do I POEL Ser TT DE En lt B 4 DRAWINGS amp BOM s BILL OF MATERIAL 2465 727 PISTON CYLINDER ASSEMBLY MEDIUM RANGE 100 PSI NO ITEM NUMBER B 5 DRAWINGS amp BOM s WS UTENT COWS L rd HOME MELK WOW 1 zr IR MEN ih mo WOJ Z 1 184001 d vide AS Te UDA SIM SJONVHITOL NET IT m M PM B 6 DRAWINGS amp BOM s BILL OF MATERIAL 2465 730 PISTON CYLINDER ASSEMBLY 35 BAR 500 PSI ITEM COMPONENT DESCRIPTION QTY N ITEM NUMBER O 1 2 3 5 7 10 1 1276 TOOLRINGRG TRUARC CR0120 015 1 000 EA 2 2460 12 10 CNTNRPSTNGCYLAPG 100 3 68 754 RETAINING 1000 4 _ 2465 7304 __ PISTON CYLASSY 35 BARNO CAL 100 5 2465 730 3 CYLINDERCONTAINER 100 7 52683 BEARING 5mmX13mmx4mm 100 EA 8 54 700 5 RING 9 16 X 1 16 70 DURO BUNA 4 00 9 A 10 54 700 1
23. E FORCLEANING THE HIGH RANGE CYLINDER init FIGURE 6 12 PREPARING KIM WIPE FOR CLEANING THE HIGH RANGE CYLIN DER 6 17 CLEANING INSTRUCTIONS THIS PAGE INTENTIO NALLY LEFT BLANK CLEANING INSTRUCTIONS 6 18 FIGURE 6 13 CLEANING THE HIGH RANGE CYLINDER FIGURE 6 14 DRYING THE HIGH RANGE CYLINDER 6 19 CLEANING INSTRUCTIONS THIS PAGE INTENTIONALLY LEFT BLANK CLEANING INSTRUCTIONS 6 20 APPENDIX A A 1 EXPLANATION OF PRESSURE CALCULATION WORKSHEET TABLES A9 ANDA11 These tables may be used with gas and hydraulic piston pressure gauges that are operated with an atmospheric reference or vacuum reference P represents the pressure at the piston reference gauge level P represents the pressure desired at the device under test and is the head pressure created by the pressure medium and the difference in height between the piston pressure gauge and the device under test A A minimum of six significant figures must be used in all calculations involving reported constants masses etc The 5 claims for accuracy assume the local gravity to be known to at least six significant figures B When the piston pressure gauge is used as a standard of pressure it is convenient to perform the pressure to mass calculations in advance of operating the standard Since the piston gauge temperature fluctuates while it is operated a confusing point in the procedure is the ne
24. EA EA A B 21 DRAWINGS amp BOM S p G 9 Fk 8 d y Las 20071197800 ww 68 12 21 musas 500 4 ES TP 97 68 12 21 soner SE 398 i S3ONVHTDL oN SI ATENISSV ENS wyka z SV U sons can a OQNvdX3 oo 01 20 68 22 E 227 r lon 5 Y 1255 1700 uaunusu wys M gt 261 83 OM Hdd SJOLLOVEd ONY SJONVYITOL 71 0310N 3 T 9 DRAWINGS amp 5 CN LO w Qus waw L L ms NN re Nr LOISONS 5 8 D z 5 m p TIVIDIA 51134 6 2 E DRAWINGS amp BOM S B 23
25. GAS LUBRICATED PISTON PRESSURE GAGE MODEL 2465A 754 USER S MANUAL RUSKA INSTRUMENT CORPORATION 10311 WESTPARK DR HOUSTON TEXAS 77042 713 975 0547 FAX 713 975 6338 E MAIL ruska ruska com http www ruska com Release 2465 2000 Revision B Date November 4 2002 INTRODUCTION WARRANTY Ruska Instrument Corporation warrants its products to conform to or exceed the specifications as set forth in its catalogs in use at the time of sale and reserves the right at its own discretion without notice and without making similar changes in articles previously manufactured to make changes in materials designs finish or specifications Ruska Instrument Corporation warrants products of its own factory against defects of material or workmanship for a period of one year from date of shipment Liability of Ruska Instrument Corporation under this warranty shall be limited to replacing free of charge FOB Houston Texas any such parts proving defective within the period of this warranty but will not be responsible for transportation charges or consequential damages This warranty is not made for products manufactured by others which are illustrated and described in Ruska catalogs or incorporated in Ruska products in essentially the same form as supplied by the original manufacturer However Ruska Instrument Corporation agrees to use its best efforts to have original suppliers make good their warranties INTRODUCTION COPYRIG
26. HT NOTICE Copyright a 1990 1991 1992 by Ruska Instrument Corporation All rights reserved This document may not be reproduced in part or in whole without the express written consent of Ruska Instrument Corporation DISCLAIMER No representations or warranties are made with respect to the contents of this user s manual Further Ruska Instrument Corporation reserves the right to revise this manual and to make changes from time to time in the content hereof without obligation to notify any person of such revision TRADEMARK NOTICE RUSK Trademarks or tradenames are subject to state and federal laws concerning their unauthorized use or other infringements The fact that the product marks or names in this manual do not bear a trademark symbol DOES mean that the product name mark is not registered as a trademark or tradename Any queries concerning the ownership or existence of any trademarks or tradenames mentioned in this manual should be independently confirmed with the manufacturer or distributor of the product a is a trademark of Ruska Instrument Corporation jil INTRODUCTION REVISION NOTICE RELEASE NUMBER REVISION DATE OF DESCRIPTION REVISION 2465A 2D00 01 30 99 Original release 2465A 2D00 11 04 02 Made numerous changes see DC RO 23708 iv INTRODUCTION REVISION HISTORY 2465A 2D00 January 30 1999 Original release 2465A 2D00 November 4 2002 Numerous changes see DC RO 23708
27. INES amp FITTING ITEM NUMBER 33 905 TEFLON 3 KSI 48 IN SWAGELOK 200 45 335 GREASE DOW HI VAC CMS 4056 762 100 86 833 TUBINGCU 2500DX 049WSOFTAN 110 000 86 856 TUBING POLYETHYLENE 66 3 8 72 000 25 DRAWINGS amp 5 Z s 2418105700 oy UN 6661 E OM 8 SE VGOVC q FIONY wna ANV gO SO OL 03509 ON 325 5 ONY S3 esf uf dm JML S ON TIV OW 13346 SHL MON 71925 ION OG EOS 65 6 2 WT EE 66 62 1 e 5 ci naw 005 1 NOLSNOH NOLLY NO NOD INZADSLSN S3ONWAJIO c SIHONI 38 SNOISNAWIO lods 552180 wia wm en wo Noam ANN OL 031 GION310S 340 ATIVNSON INFAOLNV i Cl 1404 1541 OVA 43 u3T1081NOO OINV 7 xoz veevz lt AlddNS 1531 997 56 Boo XOC VS9vC 4 y A Eee Y NT ul
28. IONSZ ATE tie 5 1 bu GENERAL OO 5 1 5 3 LOW RANGE PISTON ASSEMBLY aaa 5 2 5 4 MID RANGE PISTON ASSEMBLY 5 2 55 35 BAR ASSEMBLY L Sasu nata 5 2 5 6 HIGH RANGE PISTON ASSEMBLY 5 3 5 7 ESTABLISHING PRESSURE Lee 5 3 5 7 1 Gage 5 3 5 8 MAINTENANCE OF THE GAGE sen tale 5 4 SECTION 6 0 PISTON CYLINDER CLEANING INSTRUCTIONS 6 1 GENERAL INFORMATION AND PREPARATION 6 1 6 2 FUNCTIONAL TESTING OF PISTON CYLIN DER ASSEMBLIES 6 2 6 3 CLEANING THE LOW RANGE PISTO N CYLIN DER ASSEMBLY 6 2 64 MIDRANGEPISTON CYLINDER Feo A ie a 6 3 Viii INTRODUCTION 6 5 CLEANING THE 35 BAR PISTO N CYLIN DER ASSEMBLY 6 4 6 6 CLEANING THE HIGH RANGE PISTO N CYLIN DER ASSEMBLY 6 5 APPENDIX A CALCULATIONS EXPLANATION OF PRESSURE CALCULATION WO RKSHEET TABLES A9 AND AT onini ci ot occu dea toic Da ed deca ss A 1 APPENDIX B DRAWINGS AND BILLS OF B 1 DRAWINGS BILLS O F MATERIAL IX INTRODUCTION FIGURE 2 1 FIGURE 2 2 FIGURE 2 3 FIGURE 3 1 FIGURE 3 2 FIGURE 5 1A FIGURE 5 1 FIGURE 5 2 FIGURE 5 3 FIGURE 5 4 FIGURE 5 5 FIGURE 5 6 FIGURE 5 7 FIGURE 5 8 FIGURE 5 9 FIGURE 5 10 FIGURE 5 11 FIGURE 6 1 FIGURE 6 2 FIGURE 6
29. OEM gem ZEM ua OEM B r AINO 39ON333338 804 7 d 9 7 0 GL GC 1 Mars Ae 900 91 99 6 AIBA3SSV 1X3N c 193NN0O2 61M g GULIJNNU YOSNIS w 91M G3N IHM U j T o I a 59 S W ene ASVE 5974 LN NOLIV1O3 TE GNIS OLNO TVNIWHSI DNIA v GNOONO LATNI HALTIA Y 8T W 9052 56 TE 0t ISTINI W3ITI4 k ISINI W3ITI4 Y 149 w og gt 62 8M OL IDINNOS er 62 17 DNOTV OI IO8NNOO SOISNI 8T En TE sz GNIS OINO TVNINNEI SNIE Vy TAANA 8T 94215203 92 sz 2 CH Y GOT TH na N 8652 56 sz ITINI 7H3ITI4 Y TF TIVISId Y Z ZNS V ST V7 9192 56 re ET SONS IV 59015 GNNOWS OL LJENNOD 719 78 T 219 28 27 NED STA 8057 76 ET GI 9977 zz 82 HLIM SNOTV Z TO El TIVIOId 9 9 2MS 7 ATA 8T 9 6 zz ra AVC r Te LZM HLIM DNOTV TO F TIVIDId 9 5 2 5 aaa 8T 909 76 Te 3599 J 92 2 2MS 2MS und 81 81452 56 92 Y Y Y 61 AISW3SSV LXAN IV 6 NId ASYH NI HOLOANNOJ S W Z TOSINOS TA Z 019 72 292 76 61 81 Y 9 2MS Y OW TA Y 81 9195 76 8T LT 2 5 5 GROT zu Y das 8T 3095 56 LT 91 AISW3SSV LXAN IV 1 NId 3SV8 NI HOIOSNNOO S W 2 TIVISId TOSINOI ZA Q3H IHM ze 805 76 9T TOHLNOJ TOSINOI NYE 22 9 2 56 ET 2 ONY 89 28 0 SNI FT XIGHSSSV IXSN IV 01 NI WOIOSNNOO 5 8 Z
30. P Certified DRAWINGS amp BOM S B 14 BILL OF MATERIAL 2465 12 ASSY BRG CS PSTN PRESS GAGE COMPONENT DESCRIPTION DON EACH EACH 2460 4 12 GEAR TLTG PSTN GAGE 2 000 EACH 2460 4 13 GEAR CYL 0 PSTN DWG 1 000 2460 4 16 RTNR PLUG TLTG PSTN DWG 1 000 13 485 CLIP A D DL14 HUB 1 85 1 000 EACH EACH EACH 2460 65 CYLHSG ASSY DWG 1 000 2465 13 ASSY PRES SEAL 1 000 2460 54 2 SHAFT GEAR TLTG PSTN DWG 1 000 EACH 2465 14 ASSY VAC SEAL 1 000 EACH EACH EACH EACH EACH EACH ACH ACH ACH E EACH EACH EACH EACH EACH EACH EACH EACH EACH EACH EACH 45 339 REASE FLUO RINATED 35CS 2 02 0 000 EACH 45 338 1 OIL FLUO RINATED KRYTO X 16 02 0 000 2465 11 4 CASE BEARING AIR PISTON GAGE 1 000 EACH B 15 DRAWINGS amp BOM S i EM N PL PI LL a BIET E PER 2 222 Tot inl ur mde Ta TER 145 ans wiz yna Tas LIORUM amar __ WW m A A TA DRAWINGS amp BOM S B 16 BILL OF MATERIAL 2465 13 ASSY PRESS SEAL COMPONENT DESCRIPTION QTY U M ITEM NUMBER 2460 4 14 SEAL PRS TLTG PSTN DWG 1 000 2460 4 15 NUT PACKING TLTG PSTN DWG 1 000 45 339 GREASE FLUO RINATED 35CS 2 07 0 000 54 703 10 O RING VITON 1 4 X 1 16 X SEC 2 000 54 703 6 O RING VIT 375 25 063 1 000 B 17 DRAWINGS amp 5
31. Piston Pressure Gage to NIST presented at the Canadian National Conference of Standards Laboratories 1991 Ken Kolb Ruska Instrument Corporation Reduced Uncertainty and Improved Reliability for the Pneumatic Piston Pressure Gage Through Statistical Process Control published in the Proceedings for the Annual Measurement Science Conference 1991 2 7 CONSIDERATIONS THIS PAGE INTENTIO NALLY LEFT BLANK CONSIDERATIONS 2 8 SECTION 3 0 DESCRIPTION 3 1 GENERAL INFORMATION The Ruska Gas Lubricated Piston Pressure Gage Model 2465 see Figure 3 1 is a pneumatic pressure standard designed for the accurate generation and measurement of gas pressures to 1000 psi This measurement is accomplished in the basic manner of using the fundamental pressure equation PRESSURE FORCE AREA see Section 2 0 for more information The gage is used as the precision measuring device in the Ruska Gas Lubricated Piston Pressure G age System It may be seen from the above general equation that when a known force produced by a known mass is applied to a piston of a known area a pressure will be produced that may be calculated see Appendix A for detailed information The Ruska gage is arranged for the application of carefully determined masses on a piston of known area The primary feature of the gage is its ability to accurately reproduce its performance at the lower pressure The low viscosity of the gas provides excellent lubrication for the close f
32. SSURE GAGE BY VENTING THE PRESSURE HOUSING TO THE ATMO SPHERE Unscrew the knurled retaining cap from the top of the housing and lay it aside on a clean Kim Wipe 6 2 FUNCTIONAL TESTING OF PISTON CYLINDER ASSEMBLIES The piston cylinder assembly should be tested for cleanliness and proper operation before and after each use Perform the following steps to test for proper operation and to show that the assembly is clean 1 Install the piston cylinder assembly into the DWG base and secure the retaining cap 2 Pressure the base until the piston alone is floating near mid stroke 3 With a gentle stroke of the finger rotate the piston while also causing itto bounce in the cylinder After a few strokes allow the piston to coast on its own Although the rotation of the mid and high ranges may be lengthy the free rotation of the low range may last only a brief few seconds Atany rate all ranges should rotate freely with no sudden changes in rotation speed and should coast to a gradual stop The last bit of rotation just before stopping is often the most useful in judging if the piston is functioning correctly 4 If the piston does not perform as indicated above it should be cleaned and retested If the subsequent cleaning does not improve the results the assembly may be damaged and should not be used until a qualified inspection is made as to the source of the failure 6 3 CLEANING THE LOW RANGE PISTON CYLINDER ASSEMBLY Cleaning supplies re
33. WHTI L B 10 DRAWINGS amp BOM s BILL OF MATERIAL 2465 754 DEAD WEIGHT GAGE ASSEMBLY W FPI 110 220V COMPONENT DESCRIPTION QTY U M ITEM NUMBER A A 14 1195 CONN 14 CIRSOCKET PANEL MTG 1 000 EA 23 842 FEEDTHRU VAC 7COND 1 2 NPTM SS 1 000 2465 17 RO TATION SEN SO R ASSEMBLY 1 000 2465A 92 VAC CONN KF16 INSTR BASE 1 000 2468 82 1 BO DY JAR TALL 1 000 EA EA A A EA EA 24 16 FTG FERRULE FRONT 3 16 NYLON NY 1 000 EA 303 1 24 17 FTG FERRULE BACK 3 16 NYLON 1 000 E A EA 24 649 FTG FILTER DISC 1 000 2460 1 37 INSERT SCREW TLTG PSTN GAGE 2 000 EA EA EA EA 2460 66 SCREW ASSY LEVELING ADJUSTABLE FO O T 2 000 EA EA EA EA EA 25 64 FTG PLUG 1 8 NPT HEX HEA SO C STEEL BLACK 1 000 EA BACK FNS 24 650 FTG VENT BREATHER 1 8 M40MU ASP 1 1 000 EA BV A A A A A A A A B 11 DRAWINGS amp BOM s 1 4 9 1 3 1 0 JP DRAWINGS amp BOM s BILL OF MATERIAL 2465 754 DEAD WEIGHT GAGE ASSEMBLY W FPI 110 220V COMPONENT DESCRIPTION QTY U M ITEM NUMBER A A 14 1195 CONN 14 CIRSOCKET PANEL MTG 1 000 EA 23 842 FEEDTHRU VAC 7COND 1 2 NPTM SS 1 000 2465 17 RO TATION SEN SO R ASSEMBLY 1 000 2465A 92 VAC CONN KF16 INSTR BASE 1 000 2468 82 1 BO DY JAR TALL 1 000 EA EA A A EA EA 24 16 FTG FERRULE FRONT 3 16 NYLON NY 1 000 EA 303 1 24 17 FTG FERRULE BACK 3 16 NYLON 1
34. ce they have been washed with soap and water Scrub the bore of the cylinder using a soft bottle brush Cashmere Bouquet soap and warm tap water Rinse thoroughly and dry immediately using the pre twisted wipers Set the cylinder aside and cover with a clean dry wiper Using soft paper wiper Cashmere Bouquet soap and warm tap water scrub the outside of the piston Rinse thoroughly and dry immediately Set the piston aside and cover with a clean dry wiper Allow the piston and cylinder to set for about 15 minutes before reassembly Clean the thrust bearing cylinder container and upper retaining ring using solvent soaked wipers and set aside Inspect the o rings for any sign of damage replace as necessary Apply a slight amount of lubricant to the o rings and wipe off any excess Place the cylinder upright narrow neck upward on the work area Carefully insert the piston into the top of the cylinder and allow it to sink freely into the cylinder Do not force the piston into the cylinder or it may be damaged If lint becomes a problem a clean dry gas source can be used to blow the lint off of the parts prior to assembly Install the 6 5 CLEANING INSTRUCTIONS thrust bearing around the bottom of the piston with the flange of the outer race facing the bottom of the cylinder Install the retaining clip onto the bottom of the piston using the installation tool The end of the piston must be supported during the retaining clip installation so as not to r
35. cessity for the temperature of the gauge to be predicted prior to operation This expected temperature however is used to allow the pressure calculations to be performed Once the piston pressure gauge is floating at the intended pressure a final temperature observation is made and then trim masses are loaded onto the piston gauge to correct for any temperature variations that exist between the expected and the actual temperatures The final column in the worksheet is used to calculate the temperature coefficient which defines the amount of trim that is required to correct for this temperature change It is usually prudent to select an expected temperature which is lower than any temperature that will be experienced This is so that the operator can always add mass to correct for the actual temperature Adding mass is generally more convenient than subtracting mass from the planned loading arrangement Standard metric trim mass set is entirely suitable for this purpose All of the calculations will be performed to this expected temperature A final tim would be calculated to adjust the piston gauge to the temperature of the piston at the time of the actual measurement This correction is calculated in the last column of the worksheet This column represents the number of grams to be added to the stack of masses for a difference in the actual temperature from the expected temperature r The final trim is computed using the foll
36. changes the pressure produced by that gage Therefore the effects of gravity on the masses loaded on the piston must be considered The gravity correction is usually very significant and must be used during calculations to achieve the advertised accuracy of the piston pressure gage Confusion has resulted from the English System of units concerning the terms mass and weight The International System of units does not leave room for ambiguity and should be used whenever possible It is recognized that some facilities still operate under the English System of units Therefore this manual provides calibration data and calculation instructions in both the English and the International System of units 2 5 BUOYANT EFFECT OF THE AIR According to Archimedes s principle the weight of a body in a fluid is diminished by an amount equal to the weight of the fluid displaced The weight of an object in air that has had its mass corrected for the effects of local gravity is actually less than that corrected value indicates This reduction in weight is equal to the weight of the quantity of air displaced by the object or the volume of an object multiplied by the density of the air But the volume of an irregular shaped object is difficult to compute from direct measurement Buoyancy corrections are usually made by using the density of the material from which the object is made If the value of mass is reported in units of apparent mass vs brass standards rat
37. cilitate this Gently slide the P C assembly into the Cylinder retainer Slide the whole assembly into the gage base Inserting the Hex Wrench 94 608 into the hole in the side of the housing Place the Retaining Cap 2460 4 7 onto the cylinder housing Tighten the cap securely by hand The gage is now ready for operation 5 6 HIGH RANGE PISTON ASSEMBLY Refer to Figure 5 10 and also to drawing 2465 729 in Appendix B If the High Range Piston Assembly is to be used the Thrust Washer and the Lower Thrust Bearing mentioned in Section 5 3 can be left in the gage The High Range Piston and Cylinder can be installed as follows The Filter Filter Retainer and O Ring should be in the gage as they were in Section 5 2 Next insert the Cylinder Container 2460 6 1 and the piston and cylinder after they have been cleaned in accordance with the cleaning instructions in Section 6 0 being certain that the O Ring 54 703 113 is inserted in the Cylinder Container The O Ring should be lubricated with DuPont Krytox 240 Grease 45 339 before installation All excess lubricant should be wiped off leaving only a Slight film Place the Cylinder Retainer 2460 6 2 over the cylinder Inserting the Hex Wrench 94 608 into the hole in the side of the housing Place the Retaining Cap 2460 4 7 onto the cylinder housing Tighten the cap securely by hand The gage is now ready for operation When working at high pressures over 100 psi or after reducing a
38. degrees to 28 degrees The actual temperature is not as important as the stability in temperature There should not be excessive personnel traffic and air drafts Airborne dust is undesirable but clean room standards are not required Remove the gage from its shipping box and locate it on a clean level sturdy work surface The surface should be able to support fifty pounds of weight without deflecting and be secure enough to be free from vibration Level the base by turning the two leveling screws 0003 until the bubble in the level vial is centered Refer to plumbing connection diagrams is Appendix or to instructions in operating manual for pressure controller for proper connections to the gas source and to the test instrument The motor unit on the Piston Pressure Gage is designed to operate on either 115 VAC or 230 VAC 50 or 60 Hz After determining what the local power line voltage is at the intended location of operation select either 115 VAC or 230 VAC by the proper positioning of the voltage selector on the side of the motor unit This feature is located on the power inlet module With power cords disconnected to both Piston Pressure Gage and wall outlet use a small screwdriver to pry open the voltage select fuse compartment on the power inlet module Place two fuses of the correct value depending on local power supply conditions into their fuse holders inside the power inlet module Remove the voltage select wheel and turn it so
39. ed in Section 6 0 Precautions must always be taken to prevent uninformed and inexperienced persons from carelessly picking this assembly up for inspection The Low Range Piston Cylinder 2460 5 must always be assembled in the cylinder housing with the O ring relief on the cylinder in the downward position See Figure 5 5 GENERAL The cross section drawing 2465 12 found in Appendix will aid in identifying and assembling the following parts The Filter 24 580 the Filter Retainer 2460 4 27 and the O Ring 54 703 119 are placed in the Cylinder Housing 2460 65 in order listed The O Ring should be lightly lubricated with Dupont Krytox 240 AA Grease 45 339 before installation All excess lubricant should be wiped off leaving only a slight film These parts are used in the gage regardless of which piston is being used 5 1 OPERATION 5 3 LOW RANGE PISTON ASSEMBLY Refer to Figure 5 1 5 1A and also to drawing 2465 725 in Appendix B If the Low Range Piston Assembly is to be used the lower thrust bearing 2460 4 25 is required If the filter 24 580 and filter retainer 2460 4 27 are already in the base simply drop the lower thrust bearing into the recess at the top of the filter retainer See Figure 5 1A The o ring 54 703 119 rests on top of the filter retainer and seals against the bottom of the cylinder The lower thrust bearing must be in the gage when the Low Range Piston is being used The lower thrust bearing can be lef
40. ed with Dupont Krytox 240 AA Grease 45 339 before installation All excess lubricant should be wiped off leaving only a slight film Place the Cylinder Retainer 2460 70 2 over the cylinder Insert the Hex Wrench 94 608 into the hole in the side of the housing Place the Cylinder Retaining Cap 2460 4 7 onto the housing Tighten this cap securely by hand The gage is now ready for operation 5 5 35 BAR ASSEMBLY Refer to Figure 5 11 and also to drawing 2465 730A in Appendix B the 35 BAR Piston Assembly 15 to be used the Thrust Washer and the Lower Thrust Bearing mentioned in Section 5 3 can be left in the gage The Piston and Cylinder can OPERATION 5 2 be installed as follows The Filter Filter Retainer and O Ring should be the gage as they were in Section 5 2 Next assemble the Piston 6 Cylinder as follows All O Rings should be lubricated with DuPont Krytox 240 AA Grease 45 339 before installation All excess lubricant should be wiped off leaving only a slight film Install the O Ring 54 700 15 into the cylinder container 2465 730 3 Slide the piston through the Cylinder retainer 2465 730 4 Insert the piston into the cylinder taking care to assure the cylinder is upright The cylinder has been etched with the word to designate the proper orientation Slide the roller bearing 5 263 onto the lower portion of the piston Install the snap ring 68 754 into the groove on the piston Use the tool 2 776 to fa
41. er can be considered constant for all pressures Ruska Instrument has two types of hydraulic piston fluids available One is a Spinesstic 220 part number 55 500 which has a density of 0 031 pounds per cubic inch 858 kilograms per cubic meter The other is a Dioctyl Sebacate DOS part number 55 521 1 which has a density of 0 033 pounds per cubic inch 913 kilograms per cubic meter For gas medium piston gauges the values in Column 2 will be different for different system pressures Equations are provided to calculate the density of air or nitrogen asa function of the system pressure G Column 3 is required to adjust the mass density of the pressure medium for local gravity It is also used to correct the pressure head that exist between the reference ports of the piston gauge and device under test Column 4 is the pressure correction that is required if the reference plane of the device being calibrated is not the same plane as the reference plane of the piston pressure gauge The difference between the two planes h is positive if the reference plane of the device being calibrated is higher than the reference plane of the piston pressure gauge Column 5 is the pressure required at the reference plane of the piston pressure gauge to produce the desired pressure at the reference plane of the device being calibrated When the piston gauge is operating in the absolute mode the Reference pressure P is subtracted to obtain the diffe
42. fer to Figure 6 1 consist of 1 Solvent such as high grade alcohol or acetone Low lint paper wipers such as Kimberly Clark Kimwipes number 34155 Cleaning tool number 2460 56 Wooden applicator sticks such as Puritan number 807 12 Cashmere Bouquet brand hand soap Bottle brush such as Ruska part number 7 682 Size 0 rubber stopper such as Ruska part number 81 536 8 Warm tap water NOUR WN Prepare a clean work area near a running tap water source Prepare several sets of folded wipers as shown in figures 6 2 through 6 4 Two wipers can be folded together for wiping the outside of the piston and cylinder A single folded wiper can be inserted into then wrapped around the cleaning tool for cleaning the bore of the cylinder CLEANING INSTRUCTIONS 6 2 Disassemble the piston cylinder assembly Pre clean the piston and cylinder using solvent soaked wipers Prepare additional wipers as necessary for drying the piston and cylinder once they have been washed with soap and water Scrub the bore of the cylinder using a soft bottle brush Cashmere Bouquet soap and warm tap water Rinse thoroughly and dry immediately using the pre folded wipers wrapped around the cleaning tool Set the cylinder aside and cover with a clean dry wiper Insert the rubber stopper into the bottom of the piston Using a soft paper wiper Cashmere Bouquet soap and warm tap water scrub the outside of the piston Rinse thoroughly and dry immediately The rubber stopper can be
43. he cylinder The pressure drop occurs across the cylinder wall near the top of the cylinder at point but in the opposite direction to that of the simple cylinder in Figure 2 1 In consequence the elastic distortion is directed toward the piston tending to decease the area of the cylinder 2 1 CONSIDERATIONS Again change in area with changing pressure places limit on the usefulness of the cylinder in Figure 2 2 as a primary instrument But some benefit results from the use of this cylinder in the construction of a piston pressure gage because higher pressures may be attained without a loss in float time A small sacrifice is made in the float time at lower pressures because the total clearance between piston and cylinder must necessarily be greater at low pressure for the cylinder in Figure 2 2 than for the cylinder in Figure 2 1 In the controlled clearance design of Figure 2 3 the cylinder is surrounded by a jacket to which a secondary fluid pressure system is connected Adjustment of the secondary or jacket pressure permits the operator to change the clearance between the cylinder and piston at will series of observations involving piston sink rates at various jacket pressures leads to the empirical determination of the effective area of the assembly In the United States the controlled clearance piston pressure is the accepted standard of pressure at levels higher than those that are practical for the mercury manomete
44. he end of the piston must be supported during the retaining clip installation so as not to risk breaking the piston Install the o ring into the cylinder container Carefully insert the piston cylinder assembly into the cylinder container Do not force the cylinder into the container or it may be damaged Install the assembly into the instrument base and test according to Section 6 2 6 6 CLEANING THE HIGH RANGE PISTON CYLINDER ASSEMBLY Cleaning supplies refer to Figure 6 9 consist of 1 Solvent such as high grade alcohol or acetone Low lint paper wipers such as Kimberly Clark Kimwipes number 34155 Retaining Ring Installation Tool such as Ruska part number 2 774 Wooden applicator sticks such as Puritan number 807 12 Cashmere Bouquet brand hand soap Bottle brush such as Ruska part number 7 680 7 Warm tap water Prepare a clean work area near a running tap water source Prepare several sets of folded wipers as shown in Figures 6 2 through 6 4 Two wipers can be folded together for wiping the outside of the piston and cylinder Prepare several twisted wipers as shown in Figures 6 10 through 6 12 to wipe the bore of the cylinder Disassemble the piston cylinder assembly Insert the retaining clip from the bottom of the piston into the installation tool rinse with solvent and set aside Pre clean the piston and cylinder using solvent soaked wipers Prepare additional wipers as necessary for drying the piston and cylinder on
45. her than of true mass the density of the brass standards must be used Apparent mass is described as the value the mass appears to 2 3 CONSIDERATIONS have as determined in air having a density of 0 0012 g cm against brass standards of a density of 8 4 g cm whose coefficient of cubical expansion is 5 4 x 10 9C and whose value is based on true mass in value see reference 4 Although the trend is swinging toward the use of true mass in favor of apparent mass there is a small advantage in the use of the latter When making calculations for air buoyancy from values of apparent mass it is unnecessary to know the density of the mass If objects of different densities are included in the calculation it is not necessary to distinguish the difference in the calculations This advantage is obtained at a small sacrifice in accuracy and is probably not justified when considering the confusion that is likely to occur if it becomes necessary to alternate in the use of the two systems A satisfactory approximation of the force on a piston that is produced by the load is given by F M 1 rair rbrass k g where F the force onthe piston M Massofthe load reported as apparent mass vs brass standards Density of the air rbrass Density of brass 8 4 g cm g acceleration due to local gravity 2 6 TEMPERATURE Piston pressure gages are temperature sensitive and must therefore be corrected to a common temperature datum Variatio
46. high pressure to a lower pressure the high range piston can sometimes seem sticky even if it is clean Rotating the cylinder with the motor while gently bouncing the weights up and down usually frees the piston in a minute or so However if the piston is actually dirty no amount of rotating or bouncing will make it perform properly In that case the piston and cylinder must be cleaned 5 7 ESTABLISHING PRESSURE 5 7 1 GAGE PRESSURES Pressure should be admitted slowly into the gage preferably through a metering valve It is very convenient to have a pressure adjusting pump such as Ruska Model 2465A 800 Manual Pressure Controller to adjust the system pressure When the piston is floating suspended on a gas cushion between piston stops and not oscillating and the system is at equilibrium a reading may be taken 5 3 OPERATION When there are enough weights the piston the weights can be rotated slowly by hand opposite of the rotation of the cylinder The weights will rotate against the cylinder rotation for sometime before they begin to rotate with the cylinder When the weights begin to rotate with the cylinder they can again be rotated by hand in the opposite direction This allows the operator to observe any irregularities in the motion of the piston For example if the piston and weights quickly begin to rotate with the cylinder a dirty piston and cylinder is indicated Section 6 0 of this manual includes detailed information for pis
47. ichever is greater Optional Fine Increment Trim Set ASTM Class 1 20g to 1 mg 4 Low mass carrier and plate may be of other non magnetic material TEMPERATURE RANGE OPERATING 18 to 28 degrees C STO RAGE 40 to 70 degrees when thermometer and low range piston 6 Cylinder are stored separately from each other HUMIDITY RANGE OPERATING 20 to 75 non condensing STO RAGE 0 to 90 non condensing PRESSURE MEDIUM Clean dry gas Nitrogen or equivalent regulated to a Pressure Compatible with each particular piston cylinder assembly Dew Point of less than or equal to 60 degrees PRESSURE MAXIMUM WORKING PRESSURE With High Range Piston Cylinder 1000 PSIG With Mid Range Piston Cylinder 100 PSIG With Low Range Piston Cylinder 25 PSIG NOTE The pressurized housing has been tested to 2000 PSIG PO WER REQUIREMENTS 15 watts 115 VAC or 230 50 or 60 Hz SPECIFICATION 1 2 SECTION 2 0 GENERAL PISTON PRESSURE GAGE CONSIDERATIONS 2 1 TYPES OF PISTON PRESSURE GAGES The piston pressure gage is sometimes regarded as an absolute instrument because of the principle by which it measures pressure An absolute instrument is defined here as one capable of measuring a quantity in the fundamental units of mass length time etc It may be suggested that only certain types of piston pressure gages qualify in this category Figures 2 1 2 2 and 2 3 illustrate the three most common types of cylinder arrangements
48. in the fuse compartment Close the door until it snaps back into place 5 5 OPERATION FIGURE 5 1A STACKUP FORPISTON OPERATION OPERATION 5 6 R REFER 474 AN CYLINDER ap N SHOWN FOR NN REFERENCE LOWER THRUST N Upper Thrust Washer 2460 5 5 Retainer 2460 4 27 Lower Thrust Bearing 2460 4 25 Upper Thrust Bearing 2460 5 6 FIGURE 5 1 PARTS REQUIRED FOR LOW RANGE PISTON OPERATION 5 7 OPERATION THIS PAGE INTENTIO NALLY LEFT BLANK FIGURE 5 2 OPERATION 5 8 FIGURE 5 3 REMOVING LOW RANGE PISTON AND CYLINDER FROM CONTAINER 5 9 OPERATION THIS PAGE INTENTIO NALLY LEFT BLANK OPERATION 5 10 FIGURE 5 4 HANDLING THE LOW RANGE PISTON AND CYLINDER FIGURE 5 5 LOW RANGE PISTON AND CYLINDER SHOWING O RING GROOVE 5 11 OPERATION THIS PAGE INTENTIONALLY LEFT BLANK OPERATION 5 12 FIGURE 5 6 POSITIONING THE UPPER THRUST WASHER PISTON RETAINER IN THE CYLINDER RETAINING CAP RECESS 5 13 OPERATION THIS PAGE INTENTIO NALLY LEFT BLANK OPERATION 5 14 Lower Thrust Lower Cylinder Bearing Spacer Piston Cylinder 2460 4 25 2460 70 3 Assembly O Rings 54 703 119 Upper Cylinder Filter Spacer Retainer 2460 70 2 2460 4 27 FIGURE 5 7 PARTS REQUIRED FOR OPERATION OF THE MID RANGE P C 5 15 OPERATION THIS PAGE INTENTIO NALLY
49. ion of the piston is of uniform cross section the reference plane is found to lie conveniently at the lower extremity If however the portion of the piston submerged is not uniform the reference plane is chosen at a point where the piston with its volume unchanged would terminate if its diameter were uniform When a pressure for the piston pressure gage 15 calculated the value obtained is valid at the reference plane The pressure at any other plane in the system may be obtained by multiplying the distance of the other plane from the reference plane by the pressure gradient and adding or subtracting this value to that observed at the piston reference plane In addition gas lubricated piston pressure gage calculations should account for the fact that the pressure gradient mentioned in the preceding paragraph changes as system pressure is changed This is because the specific gravity of gas varies as a function of pressure not remaining approximately constant as does a hydraulic fluid For good work a piston pressure gage should be provided with an index mark for associating the reference of the piston with other planes of interest within a system Not only does the mark serve to establish fixed values of pressure differences through a system but it indicates a position of the piston with respect to the cylinder at which calibration and subsequent use should be conducted If the piston is tapered it is important to maintain a uniform float
50. isk breaking the piston Install the o ring into the cylinder container Carefully insert the piston cylinder assembly into the cylinder container Do not force the cylinder into the container or it may be damaged Install the assembly into the instrument base and test according to Section 6 2 CLEANING INSTRUCTIONS 6 6 FIGURE 6 1 MATERIALS FOR CLEANING LOW RANGE PISTON CYLINDER FIGURE 6 2 PREPARATIONS FOR CLEANING THE LOW RANGE CYLINDER 6 7 CLEANING INSTRUCTIONS THIS PAGE INTENTIONALLY LEFT BLANK CLEANING INSTRUCTIONS 6 8 FIGURE 6 3 PREPARING THE KIM WIPES FIGURE 6 4 PREPARING THE KIM WIPES 6 9 CLEANING INSTRUCTIONS THIS PAGE INTENTIONALLY LEFT BLANK FIGURE 6 5 CLEANING INSTRUCTIONS 6 10 THE LOW RANGE CLEANING TOOL FIGURE 6 6 PREPARATIONS THE LOW RANGE CLEANING TOOL 6 11 CLEANING INSTRUCTIONS THIS PAGE INTENTIO NALLY LEFT BLANK CLEANING INSTRUCTIONS 6 12 FIGURE 6 7 MATERIALS FOR CLEANING THE MID RANGE PISTON CYLIN DER Em FIGURE 6 8 PREPARING THE MID RANGE CLEANING TOOL 6 13 CLEANING INSTRUCTIONS THIS PAGE INTENTIONALLY LEFT BLANK CLEANING INSTRUCTIONS 6 14 FIGURE 6 9 MATERIALS FOR CLEANING THE HIGH RANGE PISTON CYLINDER FIGURE 6 10 PREPARING KIM WIPE FOR CLEANING THE HIGH RANGE CYLINDER 6 15 CLEANING INSTRUCTIONS THIS PAGE INTENTIO LEFT BLANK CLEANING INSTRUCTIONS 6 16 FIGURE 6 11 PREPARING THE KIM WIP
51. itting piston cylinder assembly Relative motion between the piston and cylinder is necessary and is obtained by an electric motor which is used to distribute the gas molecules throughout the annulus of the assembly It is relative absence of friction between piston and cylinder walls that characterizes the performance for which the gage is so highly respected A second feature of the gage is its ability to measure either absolute pressures or those referenced to the atmosphere The gage is equipped with a bell jar which when placed over the weights permits reduction of the external reference air pressure to a value of 100 microns Hg mercury at 0 degrees C The nominal range of pressure interval over which the gage is capable of operating is the span from 1 4 kPa 0 2 psi to 4 8 mPa 1000 psi This interval is covered by three interchangeable piston cylinder assemblies having sufficient overlap for establishing continuity of measurement and for making detailed investigations of subintervals within the total range span Some of the most important industrial uses of the gas lubricated piston pressure gage is that of a standard for calibrating transducers Bourdon tube type gages manometers and other dead weight gages Frequently the gage is used in combination with the pressure null transducer for investigation of volumetric behavior of gas mixtures in the PVT Pressure Volume Temperature laboratory 3 2 DESCRIPTION OF THE MASS SET A
52. l Thermal Coefficient Sink Rate at Maximum Pressure MID RANGE PISTON Pressure Range Model 2465 Pressure Range Model 2468 Pressure Uncertainty Rating Uncertainty Threshold Resolution Precision Typical Type A Unc Long Term Stability Piston Cylinder Material Thermal Coefficient Sink Rate at Maximum Pressure 35 BAR PISTON Pressure Range Model 2465 Pressure Range Model 2468 Pressure Uncertainty Rating Uncertainty Threshold Resolution Precision Typical Type A Unc Long Term Stability Piston Cylinder Material Thermal Coefficient Sink Rate at maximum Pressure HIGH RANGE PISTON Pressure Range Pressure Uncertainty Rating Uncertainty Threshold Resolution Precision Typical Type A Unc Long Term Stability Piston Cylinder Material Thermal Coefficient Sink Rate at Maximum Pressure 1 2 3 SECTION 1 0 SPECIFICATION 1 4 to 172 kPa 0 2 to 25 psi absolute gauge or negative gauge 1 1 4 to 345 kPa 0 2 to 50 psi absolute gauge or negative gauge 1 0 0010 10 ppm or 0 07 Pa 1 0E 05 psi whichever is greater 2 3 7 kPa 1 psi 1 ppm or 1 mg whichever is greater 2 ppm 3 1 ppm per year 440C Stainless Steel Tungsten Carbide 1 5E 05 per deg C typical lt 2 mm per minute maximum 4 mm per minute 12 to 700 kPa 1 7 to 100 psi absolute or gauge 12 to 1380 kPa 1 7 to 200 psi absolute or gauge 0 0010 10 ppm or 0 28 Pa 4 0E 05 psi whichever i
53. ll masses of the Mass Set except sleeve mass as supplied with this gage are made of non magnetic austenitic series 300 stainless steel They are machined from rolled stock or forging and the removal of any metal is performed in such a way as to maintain balance about the centerline Final mass adjustment is usually accomplished by drilling a symmetrical pattern of holes concentric with the axis The sleeve mass is made from two 3 1 DESCRIPTION materials The sleeve top is made from Aluminum 6061 T6 and the sleeve bottom ring is made from Titanium DESCRIPTION 3 2 Reference Vacuum Vent Level Pressure Inlet Connection Float Position Sensor Motor Switch Reference Vacuum Fine Metering Valve Pilot Light Thermometer available an option Rotation Sensor Power Inlet Leveling Screw Manual Auto Cylinder Retaining Cap Switch Reference Vacuum FPI Connector Connection KF 16 Vacuum Sensor Port RTD Port GAS LUBRICATED PISTON PRESSURE GAGE FIGURE 3 1 3 3 DESCRIPTION THIS PAGE INTENTIONALLY LEFT BLANK DESCRIPTION 3 4 Rotation Sensor Pressure Inlet Connector Connection GAS LUBRICATED PISTON PRESSURE GAGE FIGURE 3 2 3 5 DESCRIPTION THIS PAGE INTENTIONALLY LEFT BLANK DESCRIPTION 3 6 SECTION 4 0 INSTALLATION 4 1 INSTALLATION Numeric references are to drawing number 2465 754 contained in Appendix The gage should be installed in a room where the temperature is maintained between 18
54. mbly It is most likely that there may be many combinations of available masses that could be used to yield the required Total Mass However it is strongly recommended that an orderly and sequential method by used From the Mass Set Table calibration report first determine if the Sleeve Mass is required which would be the case if the realization of the Total Mass value would require the use of the larger platter masses If yes then subtract its mass value from the Total Mass value which results in a new remainder From this remainder mass value choose the next largest available mass value that may be subtracted If the choice is from one of several nominal mass platters then choose the first one in the available sequence Subtract this value from the remainder which now results in another new remainder mass value Continue this process until the remainder which now results in another new remainder mass value Continue this process until the remainder is smaller than the smallest available mass from the mass set At every step record the selected mass its mass ID number into Column 10 CALCULATIONS A 4 Column 11 remainder from Column 10 is the mass that must be placed the piston pressure gauge to complete the mass needed to set the desired pressure This remainder recorded in Column 11 is realized with the Trim Mass set provided with all Ruska Mass Sets The Ruska supplied Trim Mass Sets are defined as Clas
55. ns in the indicated pressure resulting from changes in temperature arise from the change in effective area of the piston due to expansion or contractions caused by temperature changes The solution is a straightforward application of the thermal coefficients of the materials of the piston and cylinder The area corresponding to the new temperature may be found by substituting the difference in working temperature from the reference temperature and the thermal coefficient of area expansion in the relation as follows 1 c 9 In the equation above Effective area at temperature t Effective area at zero pressure and reference temperature C Coefficient of thermal expansion 2 7 REFERENCE PLANE OF MEASUREMENT The measurement of pressure is linked to gravitational effects on the pressure medium Whether in a system containing a gas or a liquid gravitational forces produce vertical pressure gradients that are significant and must be evaluated Fluid pressure gradients CONSIDERATIONS 2 4 and buoyant forces on the piston of pressure balance require the assignment of definite position at which the relation F A exits It is common practice to associate this position directly with the piston as the datum to which all measurements made with the piston are referenced It is called the reference plane of measurement and its location is determined from the dimensions of the piston If the submerged port
56. nt soaked wipers Prepare additional wipers as necessary for drying the piston and cylinder once they have been washed with soap and water Scrub the bore of the cylinder using a soft bottle brush Cashmere Bouquet soap and warm tap water Rinse thoroughly and dry immediately using the pre twisted wipers Set the cylinder aside and cover with a clean dry wiper Using soft paper wiper Cashmere Bouquet soap and warm tap water scrub the outside of the piston Rinse thoroughly and dry immediately Set the piston aside and cover with a clean dry wiper Allow the piston and cylinder to set for about 15 minutes before reassembly Clean the thrust bearing cylinder container and upper retaining ring using solvent soaked wipers and set aside Inspect the O rings for any sign of damage replace as necessary Apply a slight amount of lubricant to the O rings and wipe off any excess CLEANING INSTRUCTIONS 6 4 Place the cylinder upright narrow neck upward on the work area Carefully insert the piston into the top of the cylinder and allow itto sink freely into the cylinder Do notforce the piston into the cylinder or it may be damaged If lint becomes a problem a clean dry gas source can be used to blow the lint off of the parts prior to assembly Install the thrust bearing around the bottom of the piston with the flange of the outer race facing the bottom of the cylinder Install the retaining clip onto the bottom of the piston using the installation tool T
57. nvert itto an absolute value by adding barometric pressure e g P 14 7 NITROGEN DENSITY ENGLISH UNITS 1 000 TO 15 000 PSIG To calculate the density of Nitrogen at pressures from 1 000 psig to 15 000 use the following equation DENSITY Ibm in 2 37465 x 10 2 74396 x 10 P 9 46069 x 10 where P PRESSURE in psi absolute if P is in gauge convert it to an absolute value by adding barometric pressure e g P 14 7 NITROGEN DENSITY SI UNITS 0 TO 6 9 MPa To calculate the density of Nitrogen at pressures from 0 01 MPa gauge to 6 9 MPa use the following equation DENSITY kg m 1 1347 E 05 xP where P PRESSURE in Pa absolute if P is in gauge convert it to Pa absolute by adding barometric pressure e g P 101325 NITROGEN DENSITY SI UNITS 6 9 MPa TO 100 MPa To calculate the density of Nitrogen at pressures from 6 9 MPa gauge to 100 MPa use the following equation DENSITY kg m 6 573 11 016 P 0 055087 where P PRESSURE in MPa absolute if P is in gauge convert it to MPa absolute by adding barometric pressure e g P 0 101325 CALCULATIONS A 6 ZERO AIR DENSITY SI UNITS 0 MPa 20 7 MPa calculate the density of Zero Air at pressures to 20 7 MPa use the following equation DENSITY kg m 1 17 E 05 xP where PRESSURE in Pa absolute if P is gauge convert it to Pa absolute by adding barometric pressure e g P 101325 HELIUM DENSITY SI UNITS
58. owing formula and loaded onto the piston gauge Temp Coef x actual temperature expected temperature 1 CALCULATIONS C The Symbol represents the effective area of the piston and its cylinder at atmospheric pressure when operating at temperature it is obtained from the relation 1 Dr where reported area of the piston at 23 degrees Celsius thermal coefficient of superficial expansion D r 23 D Gravity and Buoyancy Correction When the masses are applied to the piston in the presence of the buoyant atmosphere buoyancy corrections are necessary and are combined with gravity corrections For convenience the combined correction or is applied as a multiplier with the result indicating the quantity of apparent mass that is required to produce the desired force F on the piston FO ENGLISH UNITS K ron ae F l air J where 8 acceleration due to standard gravity 980 665 cm sec 8 acceleration due to local gravity in cm sec E density of air in g cm see Equation 4 air density of apparent mass for Apparent Mass versus Brass 8 4 g cm for Apparent Mass versus Stainless Steel 8 0 g cm When selecting masses from the calibration report assure that the values selected are in the same Apparent Mass unit of measure that was used to calculate the K or K values The apparent mass Column 9 is obtained from F where
59. p Coef Pp medium 2 Masses to Remainder an 9x NOMINAL Mass medium 7 air 2 elt be used 453 59237 PRESSURE Density Ib in Column 6 x gL 980 665 A 9 CALCULATIONS THIS PAGE INTENTIO NALLY LEFT BLANK CALCULATIONS A 10 PISTON PRESSURE GAUGE PRESSURE CALCULATION WORKSHEET SI UNITS RUSKA Date Expected Temperature t C Reference Plane Difference h m 1 c t 23 C m Mass Set Serial No Local Gravity g m sec Piston Serial No Air Density I ar g cm kg m Ao at 23 Gravity amp Buoyancy K bi MPa Tare Mass kg Mpa Reference Pressure mtorr Pa C Pg medium 2 M Remainder Temp Coef Mass Density r r 2 B A t Fx K Column 9 x NOMINAL ass Density medium air PRESSURE po Column 6 1000g kg x c RC CALCULATIONS THIS PAGE INTENTIO NALLY LEFT BLANK CALCULATIONS A 12 APPENDIX DRAWINGS AND BILLS OF MATERIAL This section contains drawings and bills of material for the Gas Lubricated Piston Pressure Gage Model 2465 754 B 1 DRAWINGS amp BOM s THIS PAGE INTENTIONALLY LEFT BLANK DRAWINGS amp BOM s B 2 BILL OF MATERIAL 2465 725 PISTON CYLINDER ASSEMBLY LOW RANGE 25 PSI SEQ COMPONENT DESCRIPTION QTY U M NO NUMBER 0002 2460 12 10 CNTNR PSTN amp CYL APG 0003 2460 12 15 SPACER CO NTAINER TLTGPSTN GAGE B 3
60. position for both calibration and use In normal operation the system is pressurized until the piston is in a floating position Slightly above the index mark After a period of time the piston and its load will sink to the line at which time the conditions within the system are stable If there is a question as to the error that may be produced by accepting a float position that is too high or too low the error will be equivalent to a fluid head of the same height as the error in the float position This statement assumes of course that the piston is uniform in area over this length 2 8 CROSSFLOATING It was mentioned earlier that some piston pressure gages must be calibrated against a standard gage In the jargon of the laboratory this process is called crossfloating When crossfloating one gage against another the two are connected together and brought to a common balance at various pressures The balancing operation is identical with that employed on an equal arm balance where the mass of one object is compared to another In each instance the operator must decide when the balance is complete In a crossfloat the two gages are considered to be in balance when the sink rate of each is normal for that particular pressure At this condition there is no pressure drop in the connecting line and consequently no movement of the pressure medium The condition can be difficult to recognize particularly if there is no means of amplification in the
61. r Piston pressure gages having very high resolutions may be made by using simple and reentrant cylinders A determination of the distortion coefficients of such gages may be made by direct comparison with a controlled clearance gage Most piston pressure gages have some elastic distortion but some used in the very low pressures have only small coefficients and in some instances correction for distortion may be neglected Measurement of pressure with the piston pressure gage is subject to uncertainties resulting from effects other than those of elastic distortion But it was appropriate that the subject of elastic distortion be discussed first since this characteristic is largely responsible for the various designs that have been developed Measurement processes proposed for high accuracy are disturbed by limitations in the performance of the equipment by small changes in the environment and by operational procedures The disturbances can be reduced to a degree by exercising control of the apparatus Some of the disturbances are difficult to control it is easier to observe their magnitudes and apply corrections for their effects The factors that affect a pressure measurement process when conducted with a piston pressure gage are described below It is important that the operator acquaint himself with these factors and become accustomed to recognizing their presence The success of the measurement will depend upon the degree to which control
62. rce the piston into the cylinder or it may be damaged If lint becomes a problem a clean dry gas source be used to blow the lint off of the parts prior to assembly Install the thrust bearing around the bottom of the piston Install the retaining nut on the bottom of the piston and tighten by hand Do not use wrenches to tighten the nut Install the o ring spacer and o rings into the instrument base Install the assembly into the instrument base and test according to Section 6 2 6 5 CLEANING THE 35 BAR PISTON CYLIN DER ASSEMBLY Cleaning supplies refer to Figure 6 9 consist of 1 Solvent such as high grade alcohol or acetone Low lint paper wipers such as Kimberly Clark Kimwipes number 34155 Retaining Ring Installation Tool such as Ruska part number 2 776 Wooden applicator sticks such as Puritan number 807 12 Cashmere Bouquet brand hand soap Bottle brush such as Ruska part number 7 680 7 Warm tap water POPE PZ Prepare a clean work area near a running tap water source Prepare several sets of folded wipers as shown in Figures 6 2 through 6 4 Two wipers be folded together for wiping the outside of the piston and cylinder Prepare several twisted wipers as shown in Figures 6 10 through 6 12 to wipe the bore of the cylinder Disassemble the piston cylinder assembly Insert the retaining clip from the bottom of the piston into the installation tool rinse with solvent and set aside Pre clean the piston and cylinder using solve
63. removed after drying but be careful not to touch the piston body Set the piston aside and cover with a clean dry wiper Allow the piston and cylinder to set for about 15 minutes before reassembly Clean the upper thrust bearing and washer using solvent soaked wipers and set aside Inspect the o ring for any sign of damage replace as necessary Apply a slight amount of lubricant to the o ring and wipe off any excess Place the cylinder upright the o ring groove at the bottom on the work area Carefully insert the piston into the top of the cylinder and allow it the sink freely into the cylinder Do not force the piston into the cylinder or it may be damaged If lint becomes a problem a clean dry gas source can be used to blow the lint off of the parts prior to assembly Install the upper thrust bearing around the stem of the piston top Install the thrust washer on top of the thrust bearing Install the assembly into the instrument base and test according to Section 6 2 6 4 RANGE PISTON CYLIN DER Cleaning supplies see Figure 6 7 consist of 1 Solvent such as high grade alcohol or acetone Low lint paper wipers such as Kimberly Clark Kimwipes number 34155 Cleaning tool No 2460 70 5 Wooden applicator sticks such as Puritan No 807 12 Cashmere Bouquet brand hand soap Bottle brush such as Ruska part number 7 681 7 Warm tap water ape Prepare a clean work area near a running tap water source Prepare several set
64. rential pressure that the piston is required to generate A 3 CALCULATIONS J The value of 1 b b which is used to determine the piston area at different system pressures is recorded in column 6 For some pistons b and or b are equal to zero Always observe the sign in front of b and b as found in the calibration report K Column 7 is used to record which is the area of the piston at pressure and at the expected temperature L Column 8 the weight load is the force required on a piston of given area to produce a given pressure F P where F Weight load or force on the piston PA Pressure as indicated in Column 5 Effective piston area at the expected temperature M Column 9 is the apparent mass that is required to produce the force listed in Column 8 N Column 10 isa listing of the different masses to be loaded on the piston pressure gauge to create the pressure listed in Column 5 The masses which will be listed here are in addition to the tare components piston surface tension effects bell jar reference pressure The mass of the tare components must be subtracted from the mass shown in Column 9 before selection of the miscellaneous masses is started After subtracting the TARE mass from the Total Mass shown in Column 9 we must now subdivide distribute the remaining required mass value among the available masses that will be loaded onto the Piston Table Asse
65. ring valve for flow control If possible hold a hand lightly on the weights to protect the piston from injury The maximum rate is 0 7 MPa 100 psi per minute Before operation be sure the retaining ring of the high pressure piston is securely in place 4 Do not operate the gage with a dirty or sticky piston 10 11 5 2 Do not rotate the pistons against the upper or lower stop longer than necessary because the bearings of necessity are not lubricated Because of extremely small tolerances between mating parts every effort should be made to insure careful handling of gage parts All parts especially those concerned with the piston and cylinder should be kept scrupulously clean Acid from finger prints can etch a piston or cylinder Handle piston and cylinder using cotton gloves on the hands to prevent acid etching of piston and cylinder walls Pistons and cylinders are matched assemblies Each piston will operate properly Only in its particular cylinder Any sound which indicates metal to metal contact between the piston and cylinder is a signal for the operator to stop the gage immediately Failure to do so may cause damage to the piston and or cylinder Always give the serial number of the instrument when ordering replacement parts The circular weight loading table of the Low Range Piston must never be permitted to enter the bore of the mating cylinder The assembly must always be handled as describ
66. rosive activity with the metals of the critical instrument parts Since these parts must necessarily be handled in making a piston exchange they may be protected from exposure to both types of contaminants by the use of clean paper wipers There are a number of industrial paper wipers such as Kimwipes available that are relatively free of lint After a little practice the corrosion sensitive parts may be safely handled with these wipers instead of with the bare fingers Even when using the wipers as insulators the hands should first be washed and thoroughly dried before beginning the disassembly The space allotted to the discussion of cleanliness is not intended to imply to the technician the impossibility of performing the job correctly but rather to give him reassurance that the results will be quite satisfactory if he follows common sense procedures of eliminating contaminations by use of proper techniques Being forewarned of the hazards the technician should wipe the bench and all instrument surfaces in the vicinity of the Piston Pressure Gage before starting disassembly operations A wad of Kim Wipes slightly wetted with a solvent such as high grade alcohol or acetone will help pick up particles that invariably accumulate near the gage 6 1 CLEANING INSTRUCTIONS A clean space should be prepared on a work bench Cover this space with paper towels so that cleaned parts will not be contaminated REMO VE ALL PRESSURE FROM THE PISTON PRE
67. s 3 Type 1 per ASTM E617 formerly Class 51 per NBS Cir 547 These fractional masses should also be used to adjust the mass load for piston pressure gauge operating temperatures that differ from the expected temperature 0 These fractional masses could also be used to adjust the mass load for the piston pressure gauge if the reference plane of the device being calibrated is ata different elevation than planned in the original head correction In the English system the remainder can be recorded in pounds in Column 11 and in grams in Column 12 The conversion factor to convert pound mass to grams is 453 59237 g lbm Q Column 13 is used to calculate a temperature coefficient This temperature coefficient is used to correct for any piston temperature variation from the expected temperature value that was used to calculate the mass loads for the various pressure points in the worksheet See item B above 5 CALCULATIONS 4 AIR DENSITY Air Density in units of g cm is calculated as follows 0 0004646 x P 4990221 6 x U x e 3550315 273 15 t where P Barometric Pressure mmHg 1 Temperature U Relative Humidity RH NITROGEN DENSITY ENGLISH UNITS 0 TO 1000 To calculate the density of Nitrogen at pressures from 0 psig to 1000 psig use the following equation DENSITY lbm in 2 826 x 105 xP where P PRESSURE in psi absolute if P is in gauge co
68. s greater 2 3 27 6 kPa 4 psi 1 ppm or 1 mg whichever is greater 2 ppm 3 1 ppm per year Tungsten Carbide Tungsten Carbide 9 1E 06 deg typical lt 2 mm per minute maximum 4 mm per minute 14 to 3500 kPa 2 to 500 psi absolute or gauge 14 to 7000 kPa 2 to 1000 psi absolute or gauge 0 0011 11 ppm or 2 8 Pa 4 0E 04 psi whichever is greater 2 3 248 kPa 36 psi 1 ppm or 1 mg whichever is greater 2 ppm 3 1 ppm per year Tungsten Carbide Tungsten Carbide 9 1E 06 per deg Typical lt 2 mm per minute maximum 4 mm per minute 14 to 7000 kPa 2 to 1000 absolute or gauge 0 0011 11 ppm or 2 8 Pa 4 0E 04 psi whichever is greater 2 3 248 kPa 36 psi 1 ppm or 1 mg whichever is greater 2 ppm 3 1 ppm per year Tungsten Carbide Tungsten Carbide 9 1E 06 deg typical lt 2 mm per minute maximum 4 mm per minute Negative gauge pressure limited by local barometric pressure Absolute mode uncertainty higher due to reference pressure sensor Approximate 95 level of confidence Refer to Section 1 2 and Calibration Report 1 1 SPECIFICATION 55 5 Approximate Total Mass Model 2465 6 31 kg Approximate Total Mass Model 2468 12 31 kg Approximate Carrier Mass 0 1 kg Smallest Increment 10 gram Mass Material 300 Series Non magnetic Austenitic Stainless Steel 4 Adjustment Method Completely machined with no fill cavities Mass Uncertainty 0 0005 5 ppm or 5E 07 kg wh
69. s of folded wipers as shown in Figures 6 2 through 6 4 Two wipers can be folded together for wiping the outside of the piston and cylinder A single folded wiper can be inserted into then wrapped around the cleaning tool for cleaning the bore of the cylinder Disassemble the piston cylinder assembly Pre clean the piston and cylinder using solvent soaked wipers Prepare additional wipers as necessary for drying the piston and cylinder once they have been washed with soap and water Scrub the bore of the cylinder using a soft bottle brush Cashmere Bouquet soap and warm tap water Rinse thoroughly and dry immediately using the pre folded wipers wrapped around the cleaning tool Set the cylinder aside and cover with a clean dry 6 3 CLEANING INSTRUCTIONS wiper Using soft paper wiper Cashmere Bouquet soap and warm tap water scrub the outside of the piston Rinse thoroughly and dry immediately Set the piston aside and cover with a clean dry wiper Allow the piston and cylinder to set for about 15 minutes before reassembly Clean the thrust bearing retaining nut upper retaining ring and lower o ring spacer using solvent soaked wipers and set aside Inspect the o rings for any sign of damage replace as necessary Apply a slight amount of lubricant to the o rings and wipe off any excess Place the cylinder upright on the work area Carefully insert the piston into the top of the cylinder and allow it to sink freely into the cylinder Do not fo
70. t in place while the High Range Piston or 35 BAR Piston are being used CAUTION When handling the Low Range Piston and Cylinder Assembly do not allow the weight loading table to enter the cylinder bore When handling the assembly maintain a firm grasp on the weight loading table until the assembly is in the housing See Figures 5 2 5 3 and 5 4 for proper handling of the Low Range Piston and Cylinder The Low Range Cylinder 2460 5 1 and Low Range Piston Assembly 2460 55 should then be placed in the gage after being cleaned according to the instructions in Section 6 0 CAUTION The O ring groove on the cylinder should be in the downward position when the cylinder is placed in the gage See Figure 5 5 When screwing the Retaining Cap 2460 4 7 onto the cylinder a slight upward force may be necessary on the piston to properly seat the Piston Retainer 2460 5 5 into the inner recess of the Retaining Cap See Figure 5 6 5 4 MID RANGE PISTON ASSEMBLY Refer to Figures 5 7 5 8 and 5 9 and also to drawing 2465 727 in Appendix the Mid Range Piston Assembly is to be used the Lower Thrust Bearing 2460 4 25 mentioned in the preceding Section 5 3 must be left in the gage with the Filter Filter Retainer and O Ring as they were in Section 5 3 Next insert the Lower Cylinder Spacer O Ring and the piston and cylinder after they have been cleaned according to the instructions in Section 6 0 The O Rings should be lubricat
71. that when it is replaced into the fuse compartment and the door is snapped shut the correct voltage is displayed through the window Plug the unit into a grounded 115 VAC or 230 VAC 50 or 60 Hz power outlet capable of handling 15 watts of power using a proper power cord suitable to the voltage CAUTION DO NOT attempt to turn the voltage select wheel while it is still in place within the fuse compartment Always remove it first from the compartment and then replace Turning the wheel while in place may damage the electrical contacts the gage is being used with an electronic thermometer insert the probe into the hole on the back left side of the base A small amount of heat sink compound on the tip of the probe will shorten the response time of the temperature sensor the optional mercury thermometer has been purchased screw it into the 1 4 NPT hole in the right hand side of the 2465 12 Assembly The graduated end of the thermometer will protrude through the hole in the right hand side of the base casting Here too a small amount of heat sink compound applied to the bulb of the thermometer will shorten the response time of the thermometer 4 1 INSTALLATION CAUTION Always remove the mercury thermometer before shipping the base INSTALLATION 4 2 5 1 SECTION 5 0 OPERATION PRECAUTIONS 1 Do not over pressure the piston Do not increase or decrease the pressure in the gage rapidly Always use a mete
72. to the table or floor The small carbide measuring piston will not likely survive an accidental drop The remainder of the components if dropped may also be damaged to the extent of sustaining raised burrs and may no longer be useable Each manual operation that is performed on a mechanical device is accompanied by a finite degree of damage The damage however small it may be for the individual operations is cumulative It results from the imperfect execution of each manual Operation After a given length of time the device may be expected to fail because of performance deterioration beyond the level of tolerance It is important therefore to perform the manual operations with the greatest possible skill in order to keep the harmful side effects ata minimum There are two types of contamination that affect not only the performance of a piston pressure gage but also the mechanical state of the critical components One contaminant is the ordinary hard particle of matter that scratches and abrades the finely finished surfaces as it becomes entrapped between the close fitting members The scratches invariably result in raised edges from the displacement of the metal and spoil the original relationship of the members The second type of contaminant is of a chemical nature and produces harmful effects by attacking the finished metallic surfaces in a corrosive manner Ordinary fingerprints contain water soluble acidic salts having extremely high cor
73. ton cleanliness checks It is suggested that motor be used only when necessary After the weights have acquired some momentum the motor may be turned off and the weights permitted to continue their rotation With this practice the piston is less likely to be operated when dirty and there will be less heat generated in the instrument from that dissipated by the motor A thermometer well is provided on the right hand side of the gage base If a mercury and glass thermometer is preferred one is available as an accessory under Ruska part number 2465 6 A PRT RTD well is provided on the back left side of the gage base Either of these methods may be used to determine gage temperature Pressure corrections for temperature changes can be made according to the methods outlined in AppendixA Leaks in the pressure system that is used with the gage cannot be tolerated Small leaks cause rapid piston fall rates and can create an error in the measured pressure Every effort should be made to insure a leak free system 58 MAINTENANCE OF THE GAGE Reference drawing 2465 12 in Appendix B Although the piston pressure gage is not a complex instrument certain maintenance procedures should be followed to insure trouble free performance The O Rings 54 703 006 on the Vacuum Seal Assembly 2465 14 and the Cylinder Housing Assembly 2460 65 have proved to be reliable and leak free The O Rings should be lubricated with DuPont Krytox 240 AA Grease 45 339

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