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Gill R3 & R3A Research Anemometers User Manual

1. 7 4 9 E EE 7 4 6 Wind Measurement SoS and Temperature Reporting Format esee 8 4 7 Analogue Input Reporting Formats sees eene trennen ener trennen 8 4 8 8 8 RD EDU ee te Mae p 8 49 Confidence Tone a enu tem Sea eee hin otia 9 4 10 Result Reporting enana ae AR Aide Reano eel io 9 4 11 Interactive Mode rn e eenn Cte HR pto tese ie ee Bl ee i 9 4 12 Configuration Commands nete et Sas de bed 9 4 13 Interrogation Commands ien tet tee Rr e pede ip Po tpe eat eie eie ees 9 5 CONNECTION TO A PC OR OTHER DEVICKE 10 6 USING THE ANEMOMETER WITH A PC RUNNING RCOM 11 6 1 PC Requirement api ett pce D p shuka 11 62 Installing oom A paci Oa E ED D AR ERE 11 6 3 Startins eget eon Pa beta b po Pa RO e E D Ee 11 6 3 T Command Tine az FR ERR Ren 11 6 3 2 Procedure if anemometer is found ann 12 6 4 Mam Men reet eodd en e a da D D b eR 13 6 5 Trend Display mer em Pac beta a Pa 13 6 6 Trend Options o egeo cda a dar D D E ER es 13 6 7 Display Micro met Parameters aiit pac ete bp P RU t kausakunku aus 13 6 8 Macro inet Parameter Opt
2. Crosswind correction for sonic temperature Page 62 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 Document No 12100009 c Page 4 of 7 Calculation of the uncorrected mean sonic temperature from the times of flight for the three axes is Straightforward The crosswind correction term looks more complicated to calculate because the wind velocity vector normal to each measurement axis has to be calculated in real time at the anemometer s sampling rate However further analysis shows that the crosswind correction term can be simplified S CROSSWIND CORRECTION OF AVERAGED SONIC TEMPERATURE The anemometer calculates the wind velocity in terms of rectangular cartesian coordinates The alignment of the u v and w wind vectors relative to the transducer axes is shown on the following diagram In this document vector quantities are represented by bold type The wind velocity represented in vector notation is u velocity 9 w However the solution for the crosswind Correction factor for data averaged over three axes is easier if the u v and w Components of velocity are expressed in polar notation ve1ocity cosbw velocity velocity sin8w ve1ocity sin w Page 63 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 Document No 12100009 C Page 5 of 7 Where 0 Azimuth angle of wind measured clockwise from u axis t Elevation angle of wind
3. A Q Page 34 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 9 USING THE PRT INPUT The Sensor Input Unit is set up to operate with any 4 wire PRT conforming to IEC 751 or DIN 43760 Compatibility with other standards may be available on request PRT connector pin out Sensor power Analogue input 6 Analogue input 6 Analogue ground PRT excitation PRT excitation PRT sense PRT sense Sensor power 0 Chassis screen A PRT connection diagram PRT excitation PRT sense PRT 100 PRT sense PRT excitation For correct operation the PRT connections must be isolated from the rest of the system Page 35 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 10 USING THE ANALOGUE OUTPUTS 10 1 Introduction Analogue outputs can be provided by an additional analogue output card mounted inside the power supply and communications unit PCI PCIs with this card fitted have a model number 1189PCA PCIs without analogue outputs have a model number 1189PC The analogue output card decodes the serial message from the anemometer and generates the appropriate analogue outputs Seven analogue outputs are provided of 14 bit resolution The pin assignment and electrical specification for these is given in Section 13 10 2 Analogue outputs Channels 1 2 and 3 Wind velocity These channels represent the wind velocity The variables repre
4. Selecting Exit or pressing the Esc key exits this menu and returns to the main menu 6 16 Tabular Display This gives a scrolling display of wind measurement The oldest results are at the top of the screen New results are added at the bottom of the screen and the whole display is scrolled upwards If all the options are turned on then the amount of data will exceed the screen width In this instance the number of decimal places used to display the analogue inputs will be reduced The data written to disc will use all decimal places and may therefore exceed eighty characters Maximum and minimum values can be displayed at the bottom of the screen Maximum and minimum are selected from the options menus The maximum and minimum display can be cleared by pressing Alt M Page 17 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 Raw data can be written to disk Pressing the Alt and D keys simultaneously Alt D will initiate a data download The user will be asked for a filename and the raw data will be written to that file The format of the download is selected from the Options Menu Once a data display has been started the Alt D combination will stop the download without ending the display Pressing the Alt and C keys simultaneously Alt C will clear the screen and start the data display from the top of the screen It does not clear the maximum and minimum display
5. Command Responses Command responses are only issued when in interactive mode Configuration Commands On receipt of a configuration command the anemometer will respond with a validation message if the command was successfully completed or an appropriate error message if it was not If a configuration command is entered with no data parameter the current data value is returned Interrogation Commands On receipt of an interrogation command the anemometer responds with the requested information if the command was successfully actioned or an appropriate error message if it was not Invalid Combinations of Commands It is possible through the setting of various parameters to request a configuration where the required output bit rate exceeds the configured baud rate If an issued configuration command requests a parameter change that would cause the above situation an appropriate error message is generated Page 29 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 COMMANDS The command descriptions use a modified form of the BNF format 0 n m lt gt IM Syntax Description EXIT Syntax Description AVERAGE Syntax Description WINDREP Syntax Description Parameters SOSREP Syntax Description Parameters Option one option from a list separated by the vertical bar must be included in the command Parenthesis used to make the possible combinations unambiguous Option
6. 8202 ou abu S3009 V N V N x va sain 25 0802 AB 03803235 Al83dO 8d SI ONY T13HSX2V8 030 31 3 OINI SQN31X3 5 NEVI N31n0 5 123 2 0 03114405 0123 02 N33809S 08 250 TI3HSHOVE 030 31 3 ISN M3N2S809 0 LNG 920 020 NO123NNOO 3SOYIH 03114405 013 5 QNVOSIO SNOU23NNOO 5307105 N3HI0 TY 01 NOUVIN3ISO 3n0102 1938800 9NIMOHS 29920 920 ww S3A331S NVWHJTI3H ONY SNOI23NNOO 830105 OL 9920 920 ww 6 1 S3A331S 1847 30193NNOO 0 IV H19N31 WWGZ ON3 YOLO3NNOD 350 1V 1010 920 3 3315 MNIIHSIVIH 30 HION31 V T1YN3AO 3A331S ONV 33H13901 53 TWNGIAION ISMI 63 41415 ONY wwSZ AB N0193NNOO 0 HIV3HS N3100 OVE 4115 WWE 5 4415 ONY wwGy AB ONJ 3SOBIH HIV3HS 33100 IIS S3LON 03123 02 LON 0350 LON 0350 LON 4 0 4 0 2 4 0 d O OND OND 5 58758 XL 58758 XY 58758 58758 A 314405 A AlddhS N334N9S 03123NNOO LON SIYM 96200 020 0 AVM GL 19920 920 22958 OIL
7. Data Display Gill Instruments Ltd Sa Sb U V W SoS 04 00 4 00 00 00 00 00 02 288 76 05 00 00 00 00 00 00 02 288 76 06 01 00 00 00 00 00 02 289 01 07 31 00 00 00 00 00 02 288 78 08 00 00 00 00 00 00 02 288 75 09 00 00 01 00 00 00 02 288 75 OA 00 00 00 00 00 00 03 288 77 01 08 00 00 00 00 00 02 288 76 02 2C 00 00 00 00 00 02 288 74 03 00 00 00 00 00 00 02 288 78 04 00 00 01 00 00 00 01 288 76 05 00 00 00 00 01 00 01 289 04 06 01 00 00 00 00 00 02 288 75 07 31 00 00 00 00 00 03 289 06 08 00 00 00 00 00 00 03 289 04 09 00 00 00 00 00 00 02 288 74 OA 00 00 00 00 00 00 02 288 77 01 08 00 01 00 00 00 01 288 75 02 2C 00 00 00 00 00 03 288 76 03 00 00 00 00 00 00 02 288 77 04 00 00 01 00 00 00 01 288 74 05 00 00 00 00 00 00 02 288 75 01 00 00 05 00 39 00 24 288 72 0A 31 00 24 00 01 00 01 289 30 lt Alt D gt Data Download Alt C Clear Screen Esc Exit Status OK Pressing the Esc key will stop any download that is in progress terminate the display and return the user to the main menu 6 17 Configure Anemometer This displays the configuration of the anemometer and allows the user to alter parameters Selecting any option except average causes a small menu to be displayed This menu offers all the possible settings for that parameter Selecting average allows the user to alter the number of firings averaged by the anemometer This can be any i
8. C ANAIP Syntax ANAIP ipno ipno 6 DIE lt 1 gt 11213141516 Description Turns on or off the specified analogue inputs Parameters ipno Analogue input channel number D Disable specified channels E Enable specified channels AOPFSD Syntax AOPFSD 10120130160 Description Specifies the analogue outputs full scale deflection Used to configure the analogue output box only POLARWRAP Syntax POLARWRAP 3601540 Description Specifies the analogue outputs polar reporting wrap angle Used to configure the analogue output box only 5 Syntax STRFMT BINARY ASCII PAD UNPAD Description Sets the result message string format Parameters BINARY Binary result message format ASCII ASCII result message format PAD ASCII fields padded to fixed size UNPAD ASCII fields unpadded ASCTERM Syntax ASCTERM CR I CRLF Description Sets ASCII output string terminator Parameters CR ASCII output string terminator is lt CR gt CRLF ASCII output string terminator is lt CR gt lt LF gt ECHO Syntax ECHO OFF I ON Description Turns on or off character echoing Parameters OFF Turn off character echoing ON on character echoing Page 31 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 MSGMODE Syntax MSGMODE CONT POLL Description Sets the message reporting mode Parameters CONT Result messages are reported continuously POLL Result messages are requested by the user BAUD
9. Suitable for marine environment EMC Emissions BS EN 50082 1 1992 EMC Immunity BS EN 50081 1 1992 Input Output Protection gt 0 8 12 4 Supply Input Supply Voltage 9 to 30VDC Anemometer Supply Current lt 300mA for 12Vdc input lt 150mA for 24Vdc input SIU Supply Current lt 200mA for 12Vdc input lt 100mA for 24Vdc input 12 5 Serial Interface Electrical Interface Full Duplex RS422 Baud Rates 2400 4800 9600 19200 38400 57600 115200 Format 8 data 1 stop bit No parity Page 49 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 12 6 Analogue Inputs Sampling Rate Diff Input Voltage Range Accuracy Resolution Common Mode Input Range Input Impedance 12 7 PRT Resolution Measurement Accuracy 12 8 Anemometer Sync Output RS422 synchronous to wind measurement 12 9 Inclinometer Range Resolution Accuracy Null Repeatability Temperature Coefficient Null Temperature Coefficient Scale Factor 1008 1 Synchronous to wind measurement 5 000 to 5 000V gt 0 05 of full scale 14 bits gt 8V gt 1M Ohm Differential gt 1M Ohm Common Mode 0 01 C lt 0 1 C 40 to 50 C lt 0 15 to 60 C monotonic over 30 of tilt 0 01 0 3 for tilt angles between 10 0 15 0 02 per C 0 2 per C 12 10 Anemometer Connector 510 Power and Data Connector Hirose 20 way socket Connector pin Designation 1 Reserved 2 RS422T
10. ALIGNUVW AXIS SPAR Description Selects UVW axis alignment from two alternative definitions Parameters AXIS Align the U axis to transducer axis 1 when viewed from above SPAR Aligns the U axis with the North spar Page 33 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 8 USING THE ANALOGUE INPUTS OF THE SENSOR INPUT UNIT The Sensor Input Unit provides six differential analogue inputs of 14 bit resolution A specification for these is given in section 12 6 This feature allows the user to power extra equipment local to the Sensor Input Unit and to take analogue data from that equipment The anemometer digitises the analogue data and appends it to the digital data string A sensor supply voltage is available at each connector The voltage at this connector is the supply voltage at the SIU minus 1 5 volts The sensor supply voltage is internally regulated to 21 2 volts for SIU supply voltages above 22 volts For sensors with a common supply and signal ground this ground should be connected to Sensor Supply In this situation Analogue Input should be connected to Sensor Supply and Analogue Ground left floating The total current drawn from the sensor supply by all the external sensors must not exceed 70mA Sensor connector pin out Sensor power Analogue input 1 3 5 Analogue ground Analogue input 1 3 5 Analogue input 2 4 6 Analogue input 2 4 6 Sensor power Chassis screen
11. C TTT TT or 0 01 C CC CC Analogue Input Fields Analogue input value in volts amp v vvvv Checksum Field Exclusive OR of all characters between STX and lt ETX gt reported as ASCII hex Page 24 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 7 1 3 Status Fields There are a number of different status codes which give the user information about various aspects of the anemometer Each of these codes has an address field followed by a data field The address field defines which particular aspect of the anemometer the following data field refers to The address fields are defined as follows StaA Status Address Address Function 00 Error codes 01 Anemometer configuration 02 Data output configuration 1 03 Data output configuration 2 04 Error code history 05 Transducer gain levels 06 Anemometer Type 07 Inclinometer X axis MSB 08 Inclinometer X axis LSB 09 Inclinometer Y axis MSB 10 Inclinometer Y axis LSB In normal operation the anemometer output cycles through the status codes 01 06 at each output sample If the anemometer detects an error then the status code 00 is displayed instead of the next cyclic status code When the error is cleared the status codes will continue to cycle from where they were interrupted If the error is caused by a transducer pair failure then the error code is displayed until the failure is rectified If the error is caused by a memory or PRT failure then after
12. measured up from horizontal velocity magnitude of wind velocity The angles of the three transducer axes relative to the anemometer s u v w axes are 0 Azimuth angle of axis 1 measured clockwise from u axis 0 degrees 6 Azimuth angle of axis 2 measured clockwise from u axis 120 degrees Azimuth angle of axis 3 measured clockwise from u axis 240 degrees Elevation angle of all axes measured up from horizontal 45 degrees for R3 and R3A 48 75 degrees for HS For each measurement axis the magnitude of the wind velocity component normal to the axis is equal to the magnitude of the vector product of velocity with the unit vectors in line with the axis The three unit vectors in line with the measurement axes are cos8 cos unit sin0 cos sind 44 cos6 cos unit sin0 sind cos8 cosh 1016 sin6 cosh 13 510 Substituting the expressions for the velocity components normal to the three transducer axes into equation 8 gives the following equation for the crosswind correction term Page 64 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 Document No 12100009 c Page 6 of 7 x dis velocity unit velocity x unit velocity x unit 14 The square of the magnitude of a vector is equal to the scalar product of the vector with itself Using this relationship the crosswind correction term become
13. 1 2 Analogue ground 2 15 Analogue output 2 3 Analogue ground 3 16 Analogue output 3 4 Analogue ground 4 17 Analogue output 4 5 Analogue ground 5 18 Analogue output 5 6 Analogue ground 6 19 Analogue output 6 7 Analogue ground 7 20 Analogue output 7 8 Analogue ground 8 21 Analogue output 8 9 Test pin 1 22 Test pin 2 10 Signal ground 23 Earth 11 Earth 24 Status output 12 Signal ground 25 Sync output 13 Signal ground 13 3 PCI Specification Electrical power requirements a 100Vac 120 10 for the 115V switch position b 200Vac 250Vac 10 for the 230V switch position c 9 30Vdc 400 max anemometer 8 15Vdc 50mA max PCI 8 15Vdc 90 max PCI with analogue outputs Environmental The desk top PCI is not sealed and is intended for use in a protected environment Page 54 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 Analogue Outputs The analogue outputs have the following specification Full scale range 2 5v to 2 5v Accuracy 0 25 of full scale 9 bits Resolution 14 bits over 3 0v Settling time 2ms to 0 25 accuracy note that the minimum time between samples is 10ms Output resistance lt 0 5Q at frequencies below 100Hz short circuit proof Load resistance Greater than 10kQ Load capacitance Between 0 and 1000pF e g up to 10m of coaxial cable Analogue Sync and Status Outputs Both Sync and status outputs conform to the following electrical specification O
14. R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 Turbulence Parameters Longitudinal turbulence intensity 9 M Transversal turbulence intensity t y M Vertical turbulence intensity 9 um M Where M JU Eriction Veloci vL nu 7 2 pe ee VI w Qsin b 1 I W sindcosh istic T i u Page 72 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 Drag Coefficient 3 29 M Obukhov Length T uj 5 es Iml KgW T Where K von Karman constant g acceleration due to gravity Momentum Flux pu Where p specfic density of air Heat Flux T Where c Specific heat of air at constant pressure a dence Kineti 2 108 3 2 Page 73 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 APPENDIX E RCOM Binary File Format Page 74 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 1 Binary File Header Description file_type file_version type serial_number average wind_report_mode string format ascii terminator echo instantaneous mode message mode confidence tone setting axis alignment setting speed of sound report mode absolute temperature report mode analogue input 1 on analogue input 2 on analogue input 3 on analogue input 4 on analogue input 5 on analogue input 6 on analogu
15. combination will stop the download without ending the display Pressing the Alt and C keys simultaneously Alt C will clear the screen and start the data display from the left with new scale values Pressing the Esc key will stop any download that is in progress terminate the display and return the user to the main menu Page 14 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 Trend Display Gill instruments Ltd S lt Alt D Data Download S lt Alt C 7 Clear Screen lt ESC gt Exit 6 14 Display Micro met Parameters Micro met Parameters screen displays micro meteorological parameters in real time The results displayed are selected and the time over which they are calculated is set in the Micro met options menu The calculations performed are described in Appendix B Calculated parameters can be written to disk The results saved are selected in the Micro met options menu and are independent of the results displayed Pressing the Alt and D keys simultaneously Alt D will initiate a data download The user will be asked for a filename and the selected calculated parameters will be written to that file The format of the download is selected from the Options Menu Once a data display has been started the Alt D combination will stop the download without ending the display Pressing the Alt and C keys simultaneously Alt C will clear the screen and re start the display Pre
16. sound T Absolute temperature A Analogue input 1 An Analogue input n cc checksum of all bytes The checksum is an exclusive OR of all bytes excluding the 2 start bytes These fields are defined as follows Wind Component Fields UVW format Wc U axis velocity in 0 01 ms l units Two s complement signed Wez axis velocity in 0 01ms 1 units Two s complement signed 1 We3 W axis velocity in 0 011187 units Two s complement signed Polar format Wc U V plane velocity direction in relative to Wez plane velocity magnitude in 0 01 187 units W axis velocity in 0 0181 units Two s complement signed Axis Speeds Wc Ultrasonic axis velocity in 0 01ms units Two s complement signed Wez Ultrasonic axis 2 velocity in 0 01ms l units Two s complement signed Wc3 Ultrasonic axis 3 velocity in 0 01ms units Two s complement signed Page 22 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 Speed of Sound Field Speed Of Sound Speed of sound in 0 010081 units Unsigned Sonic Temperature Sonic temperature in 0 01K Unsigned or 0 01 C Two s complement signed Absolute Temperature Field Absolute Temperature in 0 01K Unsigned or 0 01 C Two s complement signed Analogue Input Fields Analogue input value in twos complement 0000 0 0000V 1FFF 4 9994V E000 5 0000V Checksum Field Exclusive OR of all bytes excluding the two start bytes 7 1 2 ASCII Result Me
17. 16 consecutive failed readings the error condition is reduced to the error code history status and the error cleared StaD Status Data Address 00 Error codes Bit Function 0 Transducer pair 1 failed 1 Transducer pair 2 failed 2 Transducer pair 3 failed 3 Reserved 4 Non volatile memory error 5 PRT failed 6 Reserved 7 Reserved Page 25 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 Address 01 Anemometer configuration Bit Function 0 Reserved 1 PRT fitted 2 Reserved 3 Inclinometer fitted 4 0 U V W Axis definition U aligned with transducer axis 1 when viewed from above 1 U W Axis definition U aligned with the spar 5 Reserved 6 Reserved 7 Reserved Address 02 Data output configuration 1 Bits 1 0 00 Wind mode UVW 01 Wind mode axis 10 Polar 360 wrap 11 Polar 540 wrap Bits 3 2 00 10ms l Full Scale Deflection 01 20 1 Full Scale Deflection 10 30 1 Full Scale Deflection 11 60ms Full Scale Deflection Bits 5 4 00 SOS report off 01 SOS report speed of sound 10 SOS report sonic temp K 11 SOS report sonic temp C Bits 7 6 00 PRT temp off 01 PRT temp K 10 PRT temp C 11 Reserved Address 02 is repeated for 8 samples after a power on reset or exit from Interactive Mode to allow the analogue output card or custom PC software to recognise the output configuration Page 26 R3 amp R3A Doc No 1210 PS 0002 Issue 09 Address 03 D
18. 7 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 Vector Transformation al axis 1 velocity a2 axis 2 velocity a3 axis 3 velocity Standard vector mathematics leads to the following equations U velocity 2al a2 a3 2 1213 V velocity a3 a2 1 2247 W velocity al a2 3 2 1213 Page 58 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 APPENDIX C Sonic Temperature Measurement Page 59 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 Document No 12100009 c Page 1 of 7 SONIC TEMPERATURE MEASUREMENT 135 ON GILL INSTRUMENTS R3 Date 11 9 96 AND HS ANEMOMETERS Doc 12100009 Reviewed By Team Manager A ws xs Sect 14 1 INTRODUCTION In the past most sonic anemometers have used the times of flight on only one axis to calculate the sonic temperature However Gill Instruments R3 R3A and HS anemometers use times of flight from all three axes to derive the sonic temperature This has the following advantages US Noise reduction due to averaging over three axes 25 Reduction of errors caused by wind shadowing on a single measurement axis in specific wind directions 3 Cancellation of measurement errors caused by the anemometer head bending However stiff the head assembly is made some bending is inevitable in strong winds 4 Better correlation between the velocity and temperature measurement
19. INPU T J tedoen 10 USING THE ANALOGUE OUTPUTS 36 TO T Introd uction a ihrer ee ER Pr ER e REED e ORE ter Ren 36 10 2 ones te Te ROSE re ces 36 1086 043 Anemometer Cable Voltage Out eese enne 41 1086 G 045 Anemometer Installation Details eene enne nnne nnne 41 1189 K 022 Indoor PGD uu dte e 42 1210 K 063 R3 Anemometer U V W Axis Definition enneneenennerreneeveeeennere eeens 43 1210 K 064 Anemometer U V W Axis Definition 44 1210 K 067 Sensor Input Unit Mounting Details ee ee 45 1210 K 068 Measurement Sequence 46 1210 069 Omni Anemometer with Inclinometer 47 Assembly of Amphenol C91A Screw Lock 4 Way socket 48 12 TECHNICAL SPECIFICATION 49 12 1 Wind Measurement neee enne eene 49 12 2 Speed of Sound Measurement nana en A envenvenneeneeneenvenvenvenvenvervenneenennvenvenvenvenvenneenveneend 49 123 Environmental Ain tiet et EE cad wow uns
20. If c is the speed of sound L the distance between the transducers and there is an air flow v along the line of the transducers the following relationships are readily derived tl 2L c v t2 L c v By inverting and subtracting v is solved explicitly 0 5L 1 t1 1 t2 This wind vector derivation is not affected by or any other parameters such as temperature or contaminant content Conversely c is obtained by inverting and adding c 0 5L 1 t1 1 t2 represents the vector component of air flow resolved along the line of the pair of transducers By arranging three pairs of transducers in different orientations the direction and magnitude of the incident air flow may be unambiguously derived The transducer pairs do not have to conform to cartesian axes For optimum undisturbed airflow a non orthogonal arrangement is employed The main functions of the electronics are operation of the ultrasonics processing of raw measurement data and high level data analysis and data transmission The velocities along each transducer axis are calculated as above If the anemometer is operating ina UVW mode a transformation is then carried out to calculate the velocities in the U V W format This transformation is given below If operating in a calibrated mode a correction operation is then applied to calibrate out the affects of the transducers and head framework The UVW processed data are then output on the serial output Page 5
21. RCOM Gill Instruments Ltd WARNING No anemometer found Please ensure that the anemometer is connected And that power is available 1 Search for Anemometer Again 2 Change Serial Port 2 3 Change Base Address 02F8h 4 Change Interrupt Vector 03h 5 Exit The user should 1 Ensure that the anemometer is connected and powered up If you are using an indoor Power and Communications Interface PCI and the RX LED is flashing then the anemometer is powered up and communicating If the RX LED is NOT flashing it DOES NOT imply that the anemometer has no power the anemometer may be awaiting a command over the serial link Check that the COM port displayed 2 in the above example is correct If not select option 2 on the menu and select the correct comms port Select option 1 on the menu The software will seek the anemometer again If you are using an indoor Power and Communications Interface PCI the TX LED should flash during this process If it does not then either the serial port setting is wrong or there is a problem with the communication cable between the PC and the PCI If the anemometer is still not found then check that the settings of base address and interrupt vector are correct for your PC If not use options 3 amp 4 to correct them and option 1 to repeat the search for the anemometer Page 12 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 6 4 Main Menu
22. RS422 conversion unit which meets the specification of the anemometer The PCI supplies power for the anemometer and provides conversion of the RS422 signal sent by the anemometer and the RS232 signal required by a PC The PCI requires connection to a mains power supply or DC Computers other than IBM PC s or compatibles may require a customised cable for connection to the PCI The anemometer outputs data in RS422 format which is reconstituted to analogue if required at the PCI Baud rate options are 2400 4800 9600 19200 38400 57600 115200 paris Data format 1 8 data 1 stop no parity Page 10 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 6 USING THE ANEMOMETER WITH A PC RUNNING RCOM 6 1 PC Requirement Minimum 286 VGA and of RAM Recommended 486 DX2 66MHz 6 2 Installing RCOM The RCOM program and its auxiliary files are stored a single 3 2 disk They should be installed on the hard disk in a directory named RCOM To install the software type the following commands in this order For the user settings within RCOM to be stored correctly the RCOM directory must be in the root e g MD C RCOM COPY A C RCOM NB This assumes that your 32 drive is drive A and your hard disk is drive C If not replace A and C in the above commands with the drive letters for your 32 and hard disk drives respectively 6 3 Starting RCOM To start the RCOM Pro
23. SIML 03833425 9 316 2 6200 020 BOLDINNOI 0 AVM SI 89920 020 900 08 9821 LENY 0802 5 2810 020 OOOH HOLIINNOI 03 30 SV H19N31 iv 318 2 30 0350 LON 0350 LON 2 4 1 1 4 0 4 0 4 0 4 0 A 4 0 tA 4 0 AO WUO 58958 68958 58758 XL 58758 A 314405 A AlddNS SISSVHO 9zo 0zo OZ 50 0308 25 51 YOLD3NNOD G13IHS 9NUSIX3 1 310N N 9 02 350 Page 40 October 2004 Doc No 1210 PS 0002 Issue 09 R3 amp R3A 1086 G 045 Anemometer Installation Details 30 14 5 S9NLLNDIOIN MO T38 ININOOL 15931 LV Q InOHS SHOLO3NNOO 19 SMH3HSVM ANY SNGMOS 9N X NO aaovds Ino3 9IN X SONIXIA 0 dd 0058 V E WIN NI SNOISN3WIG T1V asn A H 13 0 ONLLNNON Page 41 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 1189 K 022 Indoor PCI i 5 3 Page 42 October 2004 Doc No 1210 PS 0002 Issue 09 R3 amp R3A 1210 K 063 R3 Anemometer U V W Axis Definition x L MA Meo S3XY gs AN 1d
24. Syntax BAUD 2400 4800 9600 19200 38400 I 57600 115200 Description Sets the serial interface baud rate Selection must be confirmed with a letter B CTONE Syntax ON OFF DISABLE Description Enables an audible confidence tone Parameters ON Enables the confidence tone OFF Disables the tone until the anemometer is next powered up DISABLE Disables the tone until the function is enabled using CTONE ON 9 Syntax 3 Description Request the current results message when in polled mode HELP Syntax HELP Description Reports a brief description of all the available commands Syntax HELP command Description Reports a description of the command requested SN Syntax SN Description Reports the anemometer s serial number VER Syntax VER Description Reports the anemometer s software version CONFIG Syntax CONFIG Description Reports the anemometer s configuration INCL Syntax INCL Description Reports the inclination of the anemometer from the vertical axis The format is XX XX YY YY Page 32 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 VERIF Syntax VERIFY E D Description Enables or disables messages to verify that commands have been carried out The verification message is the command name prefixed by e g WAVERAGE for and AVERAGE command Parameters enables verification messages D disables verification messages ALIGNUVW Syntax
25. TES 1 L U indicates lower to upper transducer firing U L indicates upper to lower transducer firing 2 Serial output of the previous measurement commences as SYNC goes high Page 46 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 1210 K 069 R3 Omni Anemometer with Inclinometer r VIEW ON TOP OF UNIT Wed R3 OMNI ANEMOMETER WITH INCLINOMETER Page 47 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 Assembly of Amphenol C91A Screw Lock 4 Way socket Page 48 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 12 TECHNICAL SPECIFICATION 12 1 Wind Measurement Measurement Rate 1005 1 Full 3 axis measurement Data Output Rates From 0 4 to 100871 Wind Speed Range 0 to 45ms 1 Wind Speed Accuracy lt 1 rms Wind Speed Resolution 0 01871 Wind Speed Offset lt 0 01ms Directional Accuracy lt 1 RMS Directional Resolution 1 12 2 Speed of Sound Measurement Measurement Rate 1005 1 Synchronous to wind measurement SOS Range 300 370ms SOS Accuracy lt 0 5 For wind speeds lt 30ms SOS Resolution 0 01ms Accuracy specifications apply for wind speeds 32m s and for wind incidence within 20 of horizontal 12 3 Environmental Operating Temperature 40 C to 60 C Storage Temperature 50 C to 75 C Relative Humidity 5 to 100 Precipitation up to 300mm hr Altitude 0 to 3000m Moisture ingress IP65
26. TYANOZIHOH 3HL OL SP IV 34Y 53 142943405 3 JHL 7415045 1 43440 3Hl OL 3 0 5 83801 JHL MOI SY 02 1310 51 5 5 4 1N3 3405v3M H2V3 20 332005SNV31 N 83440 3 1 3 ONY Z SY3SANNN 5310 N Page 43 October 2004 Doc No 1210 PS 0002 Issue 09 R3 amp R3A 1210 K 064 R3A Anemometer U V W Axis Definition 4 x X NU S3XV U313NONPONI 3 14 TYLNOZINOH 3H1 OL Sy Q3NITOMI 34v 53 14283405 3 JHL 7425045 1 43440 JHL OL 3 0 5 43801 JHL MOI 57 021 1430 51 ALI2OT3A SIXY 504 SIAY 5 3 10 4120115 1 83440 JHL AJILNIQI ONY 5 8 IHL SALON WEY Page 44 October 2004 Doc No 1210 PS 0002 Issue 09 R3 amp R3A 1210 K 067 Sensor Input Unit Mounting Details NAAQHS SW 5 IHL NO SHOLOJ3NNO2 JHL HINS GALNNOW 38 5 LINN JHL 73315 SSFINIVLS 38 JINOHS TT LNATYAINGS 40 49 SIN 51 2215 1108 d3aN3INO238 ez x uu s SAONE ONILNNOW NI SLOTS 5410 082 5410 0281 Page 45 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 1210 K 068 Measurement Sequence ULTRASONIC MEASUREMENT 3 AXIS ANALOGUE INPUT MEASUREMENT SYNC TIME 10mS NO
27. The main menu allows the selection of primary functions 1 RCOM V1 01 Gill Instruments Ltd 1 Trend display 2 Trend Options 3 Display Micro met Parameters 4 Micro met Parameter Options 5 Tabular Display 6 Configure Anemometer 7 Options 8 Exit to DOS 6 5 Trend Display This provides a graphical display of wind component trends Raw data can be written to disk See section 6 14 6 6 Trend Options This allows the user to select which parameters to display on the trend display and to select super VGA modes The software supports 800x600 and 1024x768 16 colour modes on VESA compatible super VGA cards 6 7 Display Micro met Parameters This displays micro meteorological parameters in real time Raw data and calculated parameters can be written to disk See section 6 14 6 8 Micro met Parameter Options This allows the user to select which micro meteorological parameters to display and which micro meteorological parameters to download to disk See section 6 15 6 9 Tabular Display This gives a scrolling display of wind measurement Maximum and minimum values can be displayed Raw data can be written to disk See section 6 16 6 10 Configure Anemometer This displays the configuration of the anemometer and allows the user to alter parameters See section 6 17 Page 13 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 6 11 Options This allows the user to set various optio
28. XB Data from anemometer 3 RS422TXA Data from anemometer 4 RS422RXB Data to anemometer 5 RS422RXA Data to anemometer 6 Supply V 7 Reserved 8 Reserved 9 Chassis 10 Anemometer Sync 11 Not used 12 Not used 13 Digital 0V signal ground 14 Supply V 15 Reserved 16 Reserved 17 Reserved Page 50 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 18 Anemometer Sync 19 Reserved 20 Reserved Page 51 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 13 POWER AND COMMUNICATIONS INTERFACE 13 1 Desk Top PCI This unit is for use with a single research anemometer and performs the following functions e DC supply for the anemometer for mains or de input Conversion of the RS422 anemometer serial data to RS232 for connection to a PC Transient protection for all anemometer connections Optional analogue output card Provision of an RS422 interface for transmission of serial data to a PC at higher baud rates or over long cables RS232 is not recommended for baud rates above 19200 baud or for cable lengths greater than 15 metres This is a desktop unit and not suitable for outdoor use 13 2 Connector Pin Assignments Anemometer Connector 15 way D type socket Pin Designation 1 Screen 2 RS422RXB Data from anemometer 3 RS422TXB Data to anemometer 4 Digital OV signal ground 5 Supply V 6 Sync 7 Not used 8 Sync 9 RS422RXA Data from anemometer 10 RS422TXA Data t
29. Y y H i Mean W W 1 1 Mean T W H i d E Mean Alp ge E dj Page 68 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 Variance wind variable A can be expressed as the sum of mean and turbulent A parts The variance of a the parameter G 2 is equal to the mean of the square of the turbulent A part 47 and is defined as II Q 5 2 T Q T Page 69 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 UVeov HN E n3 UWcov U W gd e Bw VWcoy V W vw V W UTcov UT UT H V T VT V T WTeov 1 W T H Page 70 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 Wind C inda canit The wind parameters in the anemometers frame of reference is translated to a natural coordinate system parallel and orthogonal to the mean wind vector Where xsig 12 21 W sindcosh ysig 6 207 176570 zsig o 1 sin 21 W sindcos Wcos lw U W sin0 0 lI lI lI Q 1 u sinO v cos0y U y 0805 VU 0 sind vur W 1 UsinO 0 Page 71
30. a limited natural life Our decision on all matters relating to complaints shall be final Any appliance or defective part which has been replaced by us shall become our property The Guarantee period applicable to all equipment shall be 12 months from despatch of the equipment except when term 11 below applies The warranty will be extended to 18 months from the despatch of the equipment following receipt by us of a properly completed warranty card taken from the User Manual supplied with the equipment Any repaired or replaced equipment shall be re delivered to the authorised distributor from whom the equipment was purchased You must arrange collection through the authorised distributor Where equipment was purchased from us you must make such arrangements with us Any repaired or replaced equipment shall be subject to this Guarantee save that in relation to repaired equipment the period of either 12 months in accordance with term 10 or 18 months in accordance with term 11 shall be replaced by the expired portion of the relevant period only Page 78
31. above data are output as 16 bit twos complement numbers In ASCII output format two hex characters are output for each status address If an inclinometer is not fitted or faulty the above addresses are not output Page 28 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 7 1 4 Software commands Command Format All commands are entered as an ASCII string consisting of a mnemonic representing the operation and zero or more parameters separated by spaces and terminated by either CR or lt CR gt lt LF gt The case of the characters in the command is ignored Commands are only valid whilst in the interactive mode with the exception of the enter interactive mode command and polled data request command ASCII Output String Termination The ASCII output string terminator can be configured to be either CR or lt CR gt lt LF gt The expression TERM is used to indicate either one of these string terminators Character Echo Character echo can be enabled or disabled If enabled received characters are only echoed while in interactive mode The Backspace Character The anemometer will respond to BACKSPACE character by deleting the previous character from its command buffer and echo lt BACKSPACE gt lt SPACE gt lt BACKSPACE gt The Escape Character The anemometer will respond to the lt ESC gt character by deleting all characters currently in it s command buffer and echo lt TERM gt lt TERM gt
32. age of settings All menu selections that set a parameter are stored in a data file on the hard disk in a file named RCOM MICROMET SET This prevents the users from having to re enter settings each time the program is run If this file cannot be found then default values will be used and the file created 6 20 RCOM Error Messages Transducer pair s X failed One or more transducer pairs indicated by X has failed This may be due to failure of one or both transducers or their associated electronics or due to a blockage in the ultrasonic path Non volatile memory error Indicates a failure in the non volatile EEPROM memory of the anemometer Absolute PRT failed Indicates failure of the PRT temperature probe or its associated electronics Configuration Mis match Indicates that the configuration reported by the status codes in Measurement Mode does not match that reported by the CONFIG command in Interactive Mode Anemometer Type Mis match Indicates that the anemometer type reported by the status codes does not match the anemometer type indicated by the serial number Page 20 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 Transducer pair s X at n gain Indicates that one or more transducer pairs indicated by X is at a high gain setting 50 90 or 100 indicated by n 6 21 Instructions For Using The Convert 3 Binary To ASCII Conversion Utility Convert 3 is used with RCOM the Solent R3 and HS resear
33. al Mise _ INSTRUMENTS Omnidirectional R3 amp Asymmetric R3A Research Ultrasonic Anemometer User Manual Doc No 1210 PS 0002 Issue 09 Anemometer Software Version 2 xx PC Software RCOM Software Version 3 xx Gill Instruments Ltd recognise all trademarks Gill Instruments Limited Saltmarsh Park 67 Gosport Street Lymington Hampshire 5041 9EG UK Tel 44 0 1590 613500 Fax 44 0 1590 613501 E mail anem gill co uk Website www gill co uk R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 Page 1 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 Page 2 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 3 SYSTEM INSTALLATION 6 6 3 2 AJP8eBIBeBt u oet cde e ea eie eite e t e nb EEEE 6 3 3 Using the Inc imormieter pt ete pei tt eee h e e tint eee 6 BA COLPOSION oren Meteen enden 6 3 5 B rthiti2 eden tro etend sd et bs ashuy asas 6 3G Calin 6 421 OD ap EEEN 7 4 2 u s beeren DRE m eei a ERR D UB Re CIN DRE 7 4 3 Measurement Mode noob den meme 7 4 4 Sampling handen Une DR
34. at Na AOS 49 12 4 Supply 49 12 Shey unu en Shausha ata aS at M OU 49 12 8 Sync Outp t 1 eee etre 50 12 9 Incliomet er n tr rene po n e pere tt ent Res 50 12 10 Anemometer Connector SIU Power and Data Connector 50 13 POWER AND COMMUNICATIONS INTERFACE 52 131 Desk Top n teiten ee oe cef E e tei cerise ee ei vba 52 13 2 Connector Pm Assignimeh s uuu ert recante etie cep do ee EE EE PER ee eere leta 52 13 3 PCIE Specification ine Sain nanne rie unto 54 Summary Of Abbreviations Used In This Manual 56 Optional Extras 9 20 tac mee e etd pa nO e a acd eb bte Beet erri 56 Principle Of Oper tiOn nitet tee tiet emer qe D Rem 57 Sonic Temperature Measurement 59 Micro met Calculations ette RR HU D a E ee t e EPOR Ueber goles 67 RCOM Binary Fil Format eet eet dii cue t PO etre th iere ad 74 Page 4 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 1 FOREWORD This manual refers to the Gill Instruments Ltd Omnidirectional R3 and Asymmetric R3A Research Ultrasonic A
35. ata output configuration 2 Bits 2 1 0 000 No inputs enabled 001 1 input enabled 010 2 inputs enabled 011 3 inputs enabled 100 4 inputs enabled 101 5 inputs enabled 110 inputs enabled 111 Notused Bit 3 0 Reserved 1 Reserved Bits 5 4 00 Reserved 01 Reserved 10 Reserved 11 Reserved Bits 7 6 00 Reserved 01 Reserved 10 Reserved 11 Reserved Address 04 Error code history Bit Function 0 Reserved 1 Reserved 2 Reserved 3 Reserved 4 Non volatile memory error 5 PRT failed 6 Reserved 7 Reserved The error history is cleared when the user enters interactive mode Page 27 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 Address 05 Transducer gain levels Bits 1 0 00 Channel pair 1 nominal 01 Channel pair 1 50 10 Channel pair 1 90 11 Channel pair 1 100 Bits 3 2 00 Channel pair 2 nominal 01 Channel pair 2 50 10 Channel pair 2 90 11 Channel pair 2 100 Bits 5 4 00 Channel pair 3 nominal 01 Channel pair 3 50 10 Channel pair 3 90 11 Channel pair 3 100 Bits 7 6 Reserved Address 06 Anemometer type Bits 2 1 0 000 Single axis 001 Omnidirectional or Asymmetric 010 Three Axis Horizontal 011 Reserved 100 Reserved 101 Reserved 110 Reserved 111 Reserved Bits 7 6 5 4 3 Not used Address 07 Inclinometer X axis MSB Address 08 Inclinometer X axis LSB Address 09 Inclinometer Y axis MSB Address 10 Inclinometer Y axis LSB The
36. ch anemometer PC software A binary file is converted to ASCII DOS command line options convert3 lt input file name gt output file name soslabstla1 a6lclinolnone If no output file name is specified then the output file name is used with a CSV file extension The anemometer status and wind data is always converted to ASCII Additional data can be selected as follows SOS speed of sound or sonic temperature abst absolute temperature al analogue input 1 a2 analogue input 2 a3 analogue input 3 a4 analogue input 4 a5 analogue input 5 analogue input 6 clino inclinometer x and y in 0 01 steps none anemometer status and wind data only Analogue inputs are output in volts to 4 decimal places If no selection of additional data is made then all the available data is converted A reminder of the above commands can be obtained by typing convert3 help Page 21 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 7 USING THE ANEMOMETER WITH A PC RUNNING YOUR SOFTWARE 7 1 Digital Serial Output Format Data is sent in either binary or ASCII format as follows 7 1 1 Binary Result Message Format OxBA OxBA StaA StaD WejL We 9H WcoL We3H We3L CH CL TH TL A L AnH AL cc where OxBA OxBA Start of result message identifier 2 bytes hex value BA StaA Status Address StaD Status Data We Wind component 1 Wc Wind component 2 Wc3 Wind component 3 C Speed of
37. d by the pulling low the relevant pin on the main 25 way connector and remain active until the pin is pulled high or allowed to go open circuit The pin assignment and electrical specification are contained in Section 13 Pulling Test Pin 1 low causes all eight analogue outputs to simultaneously cycle through the following sequence of voltages 2 50v 1 25v 0 00v 1 25v 2 50v The outputs remain at each voltage for four seconds so that the sequence repeats every twenty seconds Pulling Test Pin 2 low causes the same sequence of voltages to be output on each channel in turn while the unused channels are held at 0 00v i e the sequence is first output on channel 1 then channel 2 then 3 etc For this test the complete sequence lasts 160 seconds Page 38 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 11 DRAWINGS 1086 M 043 Anemometer Cable Voltage Out 1086 G 045 Anemometer Installation Details 1189 K 022 Indoor PCI 1210 K 063 R3 Anemometer U V W Axis Definition 1210 K 064 R3A Anemometer U V W Axis Definition 1210 K 067 Sensor Input Unit Mounting Details 1210 K 068 Measurement Sequence 1210 K 069 R3 Omni Anemometer with Inclinometer Assembly of Amphenol C91A Screw Lock 4 Way socket Page 39 October 2004 Doc No 1210 PS 0002 Issue 09 R3 amp R3A 1086 M 043Anemometer Cable Voltage Out 0 N 9801 SV y 100 318 2 3313WOMW3NV ss s oz 7 0
38. e output scale analogue output wrap file create time Number of bytes Usual data type 1 LL unsigned char unsigned char unsigned char unsigned long unsigned char unsigned char unsigned char unsigned char unsigned char unsigned char unsigned char unsigned char unsigned char unsigned char unsigned char unsigned char unsigned char unsigned char unsigned char unsigned char unsigned char unsigned char unsigned char unsigned long Comments O ASCII tabular 1 Binary tabular 2 ASCII micro met 3 Binary micro met Numeric O R3 or R3A H HS S Single axis Numeric Numeric 1 to 250 0 UVW cal 1 UVW uncal 2 Polar cal 3 Polar uncal 4 axis 0 Binary 12 ASCII pad 2 ASCII unpad 0 CR 1 CRLF 0 off 1 on 0 off 1 on 0 continuous polled on 1 off 2 disabled 0 axis 1 spar 0 off 1 speed 2 sonictemp K 3 sonictemp 0 off 1 K 2 C 0 off 1 on 0 10m s 1 20m s 2 30m s 3 60m s 0 360 1 540 file create time in seconds since 00 00 00 GMT January 1970 Page 75 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 2 Binary Data Description data valid invalid U or direction or axis velocity 1 V or magnitude or axis velocity 2 W or axis speed 3 Reserved Reserved anemometer status anemometer status address absolute tem
39. gram change directory to the RCOM directory and type RCOM CD RCOM RCOM RCOM may be followed by one or more command line options The PC will search on its serial link for an anemometer When an anemometer is found the main menu is displayed 6 3 1 Command Line Options The RCOM program may be passed one or more command line parameters Sets the COM port to use for the anemometer Valid settings n 1 2 or 4 Default is COMI CB Serial port base address If your PC has non standard serial ports it may be necessary to set the base address of the port Usually the PC can work this out from the COM port so this command should only be needed in rare circumstances For instance to set the base address to 2F8h use the command line option 2 8 CI Serial port interrupt number Sets the interrupt IRQ number used by the COM port Usually this is standard for COMI and 2 1 4 and IRQ3 respectively There are no generally accepted defaults for COM3 and COMA Therefore this command should only be necessary if you intend to use COM3 or COMA or if you have a non standard COMI or 2 Page 11 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 For example to instruct RCOM to seek an anemometer on COM3 using interrupt 4 the command would be RCOM C3 4 6 3 2 Procedure if no anemometer is found If no anemometer is found then the program displays the following menu
40. ing table shows the mapping between voltage and temperature Output voltage V 1 667 0 2 5 Celsius 40 0 60 Kelvin 233 15 273 15 333 15 Channel6 Reserved for future expansion This analogue output is not currently used Channel7 and 8 Analogue Inputs Channels 7 and 8 echo the voltage on the lowest two analogue inputs that are enabled i e the first two in the serial data message from the anemometer The analogue inputs at the anemometer are in the range 5V The analogue outputs have a range of 2 5V The voltage output is half the analogue input value For example an analogue input of 5V is echoed at 2 5V 10 3 Analogue Sync Output A logic 1 on the Analogue Sync output indicates that the analogue outputs have settled A logic 0 is generated during the period when the analogue outputs are being updated approximately 2ms duration The pin assignment and electrical specification of the Analogue Sync output are contained in Section 13 10 4 Status Output A logic 1 on the status output indicates that the analogue outputs are valid i e the full set of configuration data have been received from the anemometer and there are no data errors for the current output data The pin assignment and electrical specification of the status output are contained in Section 13 Page 37 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 10 5 Test Modes The analogue output system includes two self test modes They are activate
41. ions uoi tio e ipe OP eee 13 6 9 Tabular Display e ee e e NELE ee p d ees 13 6 10 Configure Anemoineter u uapa 13 Options nero REV etr me e ee ie etra ed ae aes 14 6 12 astakun eee ea ee 14 6 13 Trend Displays ana sasa 14 6 14 Display Micro met Parameters eneen 15 6 15 Micro met Parameter Options 16 6 16 Tab ularDispl ayy u Say tas eee deed ss 17 6 17 Configure Anemoineter ie tenor de eue e oett 18 6 18 5 MIELE 19 6 19 Storage of settings Jul n roh i erp eto arde ip eet er eerta ay 20 6 20 RCOM Error Messages PEE de neren 20 6 21 Instructions For Using The Convert Binary To ASCII Conversion Utility 21 7 USING THE ANEMOMETER WITH PC RUNNING YOUR SOFTWARE 22 TA Digital Seral Output Format usa prc er ebd 22 7 1 1 Binary Result Message Format eene nnne nennen nennen ener 22 7 1 2 ASCH Result Message Format n eet tete teret ipt e 23 7 1 4 Software Commands cheer td edere aq cette tete 29 8 USING THE ANALOGUE INPUTS OF THE SENSOR INPUT UNIT 34 Page 3 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 9 USING THE PRT
42. ith the rubber gasket This will ensure that the anemometer will provide long service under extreme conditions e g marine 3 5 Earthing For maximum protection against lightning the anemometer must be earthed via its mountings The SIU and PCI should be earthed using the earth studs provided 3 6 Cabling Ensure that strain relief measures are employed when installing the cables Do not allow the whole weight of a cable to be applied to the connector Page 6 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 4 SYSTEM OPERATION 4 1 Overview Data output rates up to 100871 Measurement of wind velocities in excess of 30ms Wind speed accuracy lt 1 RMS Accurate speed of sound measurement Configuration carried out via serial port and stored in non volatile memory High speed full duplex RS422 interface operating up to 115200 baud Background diagnostics providing the user with the confidence that the unit is operating correctly e Optional Sensor Input Unit providing 6 differential 14 bit analogue inputs and one PRT100 input e Analogue outputs representing wind speed SoS and temperature optionally fitted in PCI 4 2 Operating modes The anemometer has two operating modes 1 Measurement mode This is the normal mode of operation which is the default mode from power up 2 Interactive mode This allows the anemometer to be configured and interrogated 4 3 Measurement Mode The principle of o
43. main spar when viewed from above In this configuration U V are labelled U W The U V W axis alignment options are shown in the relevant U V W axis definition drawing in Section 11 Drawings The axis alignment can be selected using the Configuration menu within RCOM Section 6 17 or the ALIGNUVW command if using your own PC software Section 7 1 4 The speed of sound measurement results can be output in one of the following formats 1 Speed of Sound 00571 2 Sonic Temperature K 3 Sonic Temperature C Speed of sound measurements can be disabled The absolute temperature measurement results can be output in one of the following formats 1 Absolute Temperature K 2 Absolute Temperature C Absolute temperature measurements can be disabled 4 7 Analogue Input Reporting Formats If ASCII format is selected analogue input measurements are output in volts to 4 decimal places If binary format is selected analogue input measurements are output in 2 s complement The number of analogue inputs to be measured can be set from 0 to 6 4 8 Diagnostics The system reports error codes if a failure is detected of the ultrasonic transducers non volatile memory or PRT Page 8 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 4 9 Confidence Tone If this function is enabled then normal operation is indicated by an intermittent tone within the anemometer 4 10 Result Reporting The
44. nemometers They are extremely sophisticated instruments and to achieve optimum performance we recommend that you read the whole of this manual before attempting to use the instruments The Solent range is in continuous development and so specifications may be subject to change without prior notice 2 PACKING LIST e Omnidirectional or Asymmetric Research Anemometer e PCI Mounting Kit Case RCOM software This manual Page 5 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 3 SYSTEM INSTALLATION 3 1 Mounting The anemometer should be mounted in accordance with Drawing Number 1086 G 045 The SIU should be mounted in accordance with Drawing Number 1210 K 067 3 2 Alignment The anemometer has slotted fixing holes permitting 5 rotation for alignment 3 3 Using the Inclinometer The inclinometer where fitted is mounted in the base of the anemometer The data from the inclinometer can be obtained in several ways a RCOM displays this information at the bottom of the screen b by typing INCL in interactive mode see Section 7 c by decoding the upper status addresses of the anemometer output message see Section 7 3 4 Corrosion The anemometer mounting base is anodised aluminium alloy and careful note should be taken of the possibility of galvanic corrosion by incorrect mounting It is vital that only stainless steel fixings are used and that the instrument is insulated from the metal of the mounting surface w
45. nemometers and 48 75 for the HS Thus for each head design the crosswind correction term for data averaged over three axes is a weighted sum of squares of the u v and w wind velocity components This is a simple calculation which can easily be carried out in the anemometer in real time For example when 45 the sonic temperature is Ts corrected 1 oam M 0 2 0 2 193 3 0 75u2 0 75v vos 21 If the R3 R3A or HS anemometer is configured to output sonic temperature then the value it produces is corrected for cross wind according to equation 20 If it is configured to output speed of sound then the anemometer first calculates cross wind corrected sonic temperature according to equation 20 and then converts this into a speed of sound value by substituting the sonic temperature into equation 2 REFERENCES 1 JC Kaimal and JE Gaynor Another look at sonic thermometry Boundary Layer Meteorology 56 401 410 1991 Page 66 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 APPENDIX D Micro met Calculations Page 67 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 Micro met Calculati 1231 0002 C Results are calculated from the following raw data U V W Orthogonal components of the wind vector T Temperature K 25 85 Ay As analogue inputs The results are averaged over n samples Means Mean U U 1 U n 1 Mean V
46. ng Von Karman Constant Specific Density of Air Specific Heat of Air Gravity Constant or Sample Time allows the user to edit these settings The Temperature Input setting allows sonic temperature or absolute temperature from the PT100 to be used as the input parameter T The example screen shows what would be displayed with means of U V and W covariance of U with V covariance of U with W and covariance of V with W selected for display and the means U V and W selected for download to disk Page 16 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 6 Micro Meteorology Options Gill Instruments Ltd Means Natural Stand Devs Input Means Disp Log Disp Log Disp Log Mean U 4 4 xsig X X Alp 1 X X Mean V 4 4 X X AIp2 X X Mean W 4 4 zig X X Alp3 X X Mean T X X Alp4 X X Turbulence Parameters Alp5 X X Stnd Devs Disp Log Alp6 X X Disp Log tx X X Usig X X ty X X Input Stnd Devs Vsig X X tz X X Disp Log Wsig X X u X X Alplsig X X Tsig X X T X X Alpsig X X Cd X X Alp3sig X X Covariances L X X Alp4sig X X Disp Log F X X Alpsig X X Uvcov 4 X Qh X X Alp sig X X Uwcov 4 X TKE X X Vwcov 4 X Input Covariances UTcov X X Disp Log VTcov X X AlplWcovX X WTcov X X Alp2WcovX X Alp3Wcov X X User Parameter AlpaWcovX X Von Karman Constant 0 40 AIpSWcovX X Specific Density of Air 1 225 Alp6WcovX X Specific Heat of Air 1004 67 Gravity Constant 9 80 Exit Sample Time Minutes 60 Use Temperature Input Sonic Temp
47. ns These are mostly to do with writing data to disk See section 6 18 6 12 Exit to DOS This quits the program and returns the user to the operating system 6 13 Trend Display The Trend Display provides a graphical display of wind component trends Each parameter is displayed on its own set of axes and in a unique colour The labels on the Y axis give the name of the parameter and the scale The data is displayed from left to right Each sample is displayed as a separate pixel therefore the speed of the display and the resolution of the X axis is dependent on the sample rate and the resolution of the screen The X axis is labelled in seconds When the extreme right of the screen is reached the colour of the old data changes to grey and the scale is displayed on the right in grey The display then starts again from the left hand edge with new scale values U V W and magnitude are displayed in 571 Direction is displayed in degrees Temperatures are displayed either in Kelvin or degrees Celsius Analogue inputs are in volts Each display is scaled individually In the example below the W vector is scaled at 5 5 1 whilst U are scaled at z2m sl Pressing the Alt and D keys simultaneously Alt D will initiate a data download The user will be asked for a filename and the raw data will be written to that file The format of the download is selected from the Options Menu Once a data display has been started the Alt D
48. nteger value between 1 and 250 Page 18 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 The example shows the Message Mode sub menu popped up over the configuration screen Selecting EXIT or pressing the Esc key exits this menu and returns to the main menu 2 Configuration Gill Instruments Ltd Serial Number 0123456 Data Reported Reporting Speed Report Mode UVW CAL Average 10 Speed of Sound mode SPEED Baud Rate 19200 Absolute Temp Mode OFF Analogue String Format Channels enabled DDDDDD String Format BINARY Full Scale Deflect 30 ASCII Terminator CRLF Direction Wrap Mode 360 Echo Message Mode Additional Features Confidence Tone DISABLED POLL Axis Alignment AXIS EXIT 6 18 Options This allows the user to set various options These are mostly to do with writing data to disk Selecting Output Field Separator allows the user to select what separator will be used in ASCII mode downloads The choices are Comma Space Tab or Semi Colon If the download format is set to Binary than this option has no effect Selecting Output Line Terminator allows the user to select what terminator will be used at the end of lines in ASCII mode downloads The choices are carriage return CR or carriage return and line feed CR LF If the download format is set to Binary than this option has no effect Selecting Download format allows the user to choose whether to store da
49. o anemometer 11 Supply V 12 Reserved 13 Reserved 14 Not used 15 Reserved RS232 connector 9 way D type socket Pin Designation DCD RXD data from anemometer to PC TXD data from PC to anemometer DTR Signal Ground DSR RTS CTS O QA L Page 52 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 RS422 connector 9 way D type socket Pin Designation 1 Not used 2 Not used 3 Not used 4 RS422 RXA data from PC to PCI 5 Signal GND 6 RS422 TXA data from PCI to PC 7 RS422 TXB data from PCI to PC 8 RS422 RXB data from PC to PCI 9 Earth Screen D C Supply Amphenol C91A Screw Lock 4 Way Socket Pin Designation 1 PCI V 2 PCI V 3 Anemometer V 4 Anemometer V View of PCI Plug 19 227 Auxiliary Output 9 way D type plug Pin Designation 6 Anemometer Sync 7 Anemometer Sync Page 53 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 Recommended Line Termination Anemometer Sync 51R 51R 25422 line receiver Anemometer Sync RX0v Note The above termination is for when the receive circuit 1s floating relative to the anemometer If the receive circuit is referred to Anemometer Signal Ground or Anemometer Supply then the earth connection marked e should be omitted Analogue Output Connector 25 way D type plug Pin Designation Pin Designation 1 Analogue ground 1 14 Analogue output
50. peration is described in Appendix A The parameters sampled are determined by the anemometers configuration and consist of 1 Wind velocity axis velocities are always sampled 2 Speed of Sound SoS 3 Analogue Inputs 6 4 Absolute Temperature PRT100 The way in which the results are calculated formatted and reported depends upon the configuration of the anemometer 4 4 Sampling Wind velocity SoS and analogue inputs are sampled every 10ms in a fixed sequential pattern The PRT100 is sampled every 40ms The measurement sequence is shown in Drawing Number 1210 K 068 4 5 Averaging These samples are block averaged before being converted into results For wind speed SoS and analogue inputs the number of samples used in the block average can be set to between 1 and 250 samples The corresponding maximum number of PRT100 samples per result is 62 Page 7 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 4 6 Wind Measurement SoS and Temperature Reporting Format The wind measurement can be output in one of the following formats 1 U V amp W calibrated 1 U V amp W uncalibrated 8 1 Polar amp W calibrated amp ms Polar amp W uncalibrated amp ms Axis velocities uncalibrated ms s In U V W modes the alignment of the U axes can be selected as follows Axis U in line with Axis 1 when the anemometer is viewed from above Spar U is in line with the
51. perature speed of sound sonic temperature analogue input 1 analogue input 2 analogue input 3 analogue input 4 analogue input 5 analogue input 6 Number of bytes Usual data type 1 unsigned char short int short int short int unsigned char unsigned char unsigned short int or short int unsigned short int or short int long long long long long long Neme ANN N Comments O valid string 1 otherwise invalid string 2 checksum error 3 checksum error and invalid string velocity in 0 01m s direction in degrees velocity in 0 01m s velocity in 0 01m s 0 01K increments unsigned 0 01 C increments signed in 0 01 m s or 0 01K increments unsigned 0 01 C increments signed analogue input Page 76 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 Notes On Binary File Format Analogue Inputs If the anemometer output string format is ASCII the analogue inputs are stored in the binary file in 100uV increments from 5V to 5V If the anemometer output string format is binary then analogue inputs are stored in the binary file as follows Voltage Analogue Input Value 4 9994 8191 0 0000 0000 5 0000 8192 Page 77 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 Gill Instruments Ltd Terms of Guarantee This Guarantee is in addition to and does not in any way affect any statutory or other legal rights including but not limited to the pu
52. rchaser s right to redress if the equipment is not a as described b of satisfactory quality or c fit for its purpose If within the applicable guarantee period as shown in 10 below the equipment proves to be defective by reason of faulty design workmanship or materials we undertake subject to the following terms to have the defective equipment or any parts thereof repaired or at our discretion replaced free of charge 1 10 11 12 13 The equipment shall have been purchased and used solely in accordance with standard operating instructions supplied with the equipment and the technical and or safety standards required in the country where the equipment is to be used The equipment should be returned together with proof of purchase promptly on being found defective at the purchaser s risk and expense to the authorised distributor from whom the appliance was purchased or to Gill Instruments Limited if purchased from us All initial enquiries must be made through the authorised distributor except in cases where purchase was from us This Guarantee shall not apply to damage caused through fire accident misuse wear and tear neglect incorrect adjustment or repair to damage caused through installation adaptation modifications or use in an improper manner or inconsistent with the operating instructions supplied with the equipment or the technical and or safety standards required in the country where the equipment is used or
53. s Tess 4 velocity x unit velocity x unit velocity x unit velocity x unit velocity x unit velocity x unit 15 To find the expression for the crosswind correction term substitute equations 10 11 12 and 13 into equation 15 and simplify the result The intermediate calculations are not reproduced in this document because they take up a lot of space To minimise the risk of errors in the calculation the solution was found using the Maple symbolic engine included in Mathcad PLUS 5 0 The solution is 2 3 Teross vero sty cos cos w 5 cos 16 This can be expressed in terms of the u v and w velocity components by making the substitutions velocity w 17 2 v2 2 TEM 6 5 57 w 18 Which gives the following result 2 11 e052 w Teross or 277 9 19 Substituting this expression for the crosswind correction term back into equation 7 results in the following equation for Sonic temperature averaged over three measurement axes with crosswind correction applied Page 65 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 Document No 12100009 C Page 7 of 7 1 2 12 1 2 Ts corrected H u v 2 w2cos 403 3 2 20 The elevation angle of the transducer paths is a constant It is 45 for the R3 and R3A a
54. s since both are derived from the same set of six transit times 5 Simpler implementation because crosswind correction can be carried out without complicated vector algebra or trigonometric functions 2 SONIC TEMPERATURE MEASUREMENT FOR A SINGLE AXIS Reference 1 gives a clear description of the principle of sonic thermometry Its main results relevant to this technical note are reviewed in sections 2 and 3 before widening the discussion to cover the measurement of sonic temperature using data from three measurement axes Assuming that there is no crosswind the speed of sound is evaluated over single measurement axis e g axis 1 according to the following formula i d ED 1 2 up U down 1 Page 60 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 Document No 12100009 C Page 2 of 7 The corresponding sonic temperature which closely approximates the virtual temperature of the air is calculated according to the following equation e 403 2 Finally the true temperature may be calculated according to equation 3 if concurrent humidity measurements are available However the sonic anemometers manufactured by Gill Instruments do not carry out this calculation because they do not incorporate humidity sensors Tsi 0 32 Where Ci speed of sound evaluated over axis 1 4 distance between transducers on axis 1 time of flight on axis 1 in one direc
55. selected parameters are blocked together along with the diagnostic results and block control information to form a result message The result message can either be in a Binary or ASCII format In the ASCII format the fields can be padded to form a fixed field size if required The way the result message is transmitted is dependent on the reporting mode 18 Continuous mode the result message is transmitted immediately after calculation 2 Polled mode the host pc requests data from the anemometer The anemometer responds by sending the current result message 4 11 Interactive Mode Interactive mode is entered from measurement mode by sending the anemometer the appropriate command In this mode the user can communicate with the anemometer issuing configuration commands to the anemometer or requesting information from the anemometer 4 12 Configuration Commands Configuration commands allow the user to configure the anemometer as required The configuration parameters are held in non volatile storage allowing the anemometer to retain its current configuration when powered down 4 13 Interrogation Commands Interrogation commands allow the user to request various information from the anemometer Page 9 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 5 CONNECTION TO A PC OR OTHER DEVICE Connection to a PC or other device requires the use of 1 Either a standard PCI d Or a suitable alternative power supply and
56. sented by each channel depend on the anemometer s operating mode and are defined in the following table Output Channel Mode 1 2 3 UVW U V W Polar format Dir Mag W Axis velocities Axis 1 Axis 2 Axis 3 For U V and W magnitude and axis velocities 2 5V represents 10 20 30 60m s as selected when configuring the anemometer For direction in polar format the 2 5V output range represents either 360 or 540 This option is also set up when configuring the anemometer either using the supplied RCOM software or using the anemometer interactive mode commands The direction representation is Output voltage V 2 5 0 833 0 40 833 2 5 360 180 0 180 540 0 180 360 540 The 540 mode avoids the output oscillating between 2 5V and 2 5V in response to a direction varying around 180 Page 36 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 Channel 4 Speed of Sound or Sonic Temperature The variable represented by this analogue output also depends on the configuration of the anemometer s speed of sound or sonic temperature The representations for each available mode are Output voltage V 2 5 1 667 0 2 5 Speed of Sound 300 311 667 335 370 Sonic temperature Kelvin 233 15 273 15 333 15 Sonic temperature Celsius 40 0 60 Channel5 Absolute Temperature The voltage output at a given temperature is independent of the anemometer s temperature output configuration The follow
57. ssage Format lt STX gt StaA StaD Wc41 Wco Wc4 C T A Ag XETX cc TERM where lt STX gt Start of string character ASCII value 2 StaA Status Address StaD Status Data We Wind component 1 2 Wind component 2 We 3 Wind component 3 C Speed of sound T Absolute temperature A Analogue input 1 An Analogue input n lt ETX gt End of string character ASCII value 3 cc checksum of all characters between lt STX gt and lt ETX gt TERM CR or lt CR gt lt LF gt user selectable Page 23 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 These fields are defined as follows Wind Component Fields UVW format Wc U axis velocity in 0 01ms units UU UU Wez axis velocity in 0 01ms 1 units zVV VV We3 W axis velocity in 0 01ms units Polar format Wc U V plane velocity direction in relative to N DDD Wc UV plane velocity magnitude in 0 01ms l units MM MM Wez W axis velocity in 0 01ms l units WW WW Axis Speeds Wc Ultrasonic axis 1 velocity in 0 011151 units XA1A1 A1A1 Wc Ultrasonic axis 2 velocity in 0 01ms l units XA5A25 A5A2 Wc3 Ultrasonic axis 3 velocity in 0 01ms l units Speed of Sound Field Speed Of Sound Speed of sound in 0 01ms units CCC CC Sonic Temperature Sonic temperature in 0 01K KKK KK or 0 01 C CC CC Absolute Temperature Field Absolute Temperature in 0 01K or 0 01
58. ssing the Esc key will stop any download that is in progress terminate the display and return the user to the main menu Page 15 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 The example screen shows what would be displayed with mean and standard deviation U V and W covariance of U with V covariance of U with W covariance of V with W U and Cd selected for display Micro met Parameters Gill Instruments Ltd Mean U 0 168 m s Mean V 0 001 m s Mean W 0 140 m s Usig 0 237 m s Vsig 0 166 m s Wsig 0 087 m s Uvcov 0 024 m2 s2 Uwcov 0 003 m2 s2 Vwcov 0 002 m2 s2 u 0 000 m s Cd 0 000 lt Alt D gt Data download lt Alt C gt Clear Screen lt Esc gt Exit Status OK Pressing the Esc key exits this display and returns to the main menu 6 15 Micro met Parameter Options This allows the user to select which micro meteorological parameters to display and which micro meteorological parameters to download to disk It also allows the setting of various user defined parameters The calculations performed to derive these parameters are contained in Appendix B For each parameter there are two entries Each may be either a tick or a cross If the entry under the Disp label is a tick then that parameter will be displayed on the micro met parameters screen If the entry under the Log label is a tick then that parameter will be written to disk Selecti
59. ta in ASCII or Binary ASCII files are suitable for reading into a text editor or spreadsheet directly They take longer to write and may require more disk space than binary files Binary data needs to be converted to ASCII by a separate program before reading into a text editor or spreadsheet The conversion program Convert 3 is supplied with the anemometer for this purpose Instructions for Convert 3 are provided in section 6 21 The binary file format is specified in Appendix E Output Field Separator Output Line Terminator and Download format affect downloads from the trend display the micro met parameter display and the tabular display Selecting Display Maxima and Minima toggles the display of maximum and minimum values in tabular display on or off Page 19 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 Selecting Output Period allows the user to enter an averaging period 1 to 60 mins for use when displaying and logging data in trend and tabular display mode A time of 0 gives no averaging Averaging period selected is displayed after the status code Selecting Return to Main Menu or pressing the Esc key exits this menu and returns to the main menu 4 Options Gill Instruments Ltd 1 Output Field Separator COMMA 2 Output Line Terminator CR LF 3 Download Format ASCII 4 Display Maxima and Minima On 5 Output Period 6 Return to Main Menu 6 19 Stor
60. the simplified equations 1 and 2 and subsequently corrected by adding a term derived from the crosswind component MEASUREMENT AXES 4 SONIC TEMPERATURE MEASUREMENTS AVERAGED OVER THREE The sonic temperature may also be derived from the other two measurement axes giving the following formulae cz Vz Tg corrected os 03 5 2 2 C3 Vn3 2 Tg corrected 103 103 6 Where C2 speed of sound evaluated over axis 2 Ts2 sonic temperature evaluated over axis 2 Va2 the component of wind velocity normal to axis 2 C3 speed of sound evaluated over axis 3 sonic temperature evaluated over axis 3 the component of wind velocity normal to axis 3 The axis speeds of sound c2 and are calculated by substituting the times of flight and path length for the relevant axis into equation 1 Calculating the mean of the three sonic temperature measurements results in the benefits identified in section 1 of this technical note The mean sonic temperature is 2 2 2 2 2 2 EEA PE Ts corrected REN 403 403 The first term in this equation is the mean of the sonic temperatures for the three measurement axes ignoring the effects of crosswind This is subsequently corrected by adding the second term which is the crosswind correction factor T Af cross 3 403 403 403 8 Where Ts the mean sonic temperature for all three axes
61. the symbols within the square braces are optional Repeat the symbols inside the braces can be repeated n to m times If n is not included then 0 is implied if m is not present then infinity is implied Non literal symbol this represents other non literal and literal symbols A further definition is required to define this non literal symbol IM Switches from measurement mode to interactive mode EXIT Exits from interactive mode back to measurement mode AVERAGE 1 250 Sets the number of samples used in the block average WINDREP UVW I POLAR CALI UNCAL AXIS Sets the wind measurement reporting format UVW Reports wind velocity in UVW format POLAR Reports wind velocity in polar W format AXIS Reports wind as axis velocities CAL Wind results are calibrated UNCAL Wind results are uncalibrated SOSREP OFF SPEED SONICTEMP C Sets the speed of sound reporting format OFF SOS reporting is turned off SPEED SOS is reported as speed SONICTEMP SOS is reported as sonic temperature K Sonic temperature reporting in K C Sonic temperature reporting in C Page 30 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 ABSTEMP Syntax ABSTEMP OFF ON KIC Description Enables and disables absolute temperature reporting from the PRT sensor Parameters OFF PRT temperature reporting turned off ON PRT temperature reporting turned on K PRT temperature reporting in K C PRT temperature reporting in
62. tion ti aom time of flight on axis 1 in other direction sonic temperature evaluated over axis 1 T true temperature Kelvin e vapour pressure of water in air p absolute pressure Equation 1 assumed that there was no crosswind i e no component of wind normal to the measurement axis However this is not a valid assumption and can result in significant error unless corrected The method of crosswind correction is described in the next section 3 CROSSWIND CORRECTION OF SONIC TEMPERATURE MEASURED ON A SINGLE AXIS The component of wind velocity normal to measurement axis 1 causes an error in the sonic temperature measurement In the Presence of such a crosswind the formulae in section 2 give sonic temperature and speed of sound values lower than the true values The reason for this is that sound arriving at the receiving transducer left the transmitting transducer heading slightly up wind and was blown back on course thus travelling further than the straight line path length between the two transducers Reference 1 derives the correction for crosswind errors Applying the correction to the equations of section 2 gives corrected 103 03 4 Where the component of wind velocity normal to axis 1 Page 61 R3 amp Doc No 1210 PS 0002 Issue 09 October 2004 Document No 12100009 C Page 3 of 7 In other words the sonic temperature may initially be calculated according to
63. to damage occurring during transit to or from the purchaser If at any time during the Guarantee period any parts or parts of the equipment are replaced with a part or parts not supplied or approved by us or the equipment has been dismantled or repaired by a person not authorised by us the purchaser shall not be entitled to any rights and or remedies under this guarantee Under this Guarantee we will repair at our discretion replace defective equipment or any part or parts and this shall be the limit of liability under this Guarantee Some product models may require adjustment and or adaptation for proper performance and safe use in countries other than the United Kingdom in accordance with local voltage requirements and safety or other technical standards imposed or recommended by applicable regulations For certain product models the cost of such adjustment or adaptation may be substantial and it may be difficult to satisfy local voltage requirements and safety or other technical standards It is strongly recommended that the purchaser investigate these local technical and safety factors before using the appliance outside the United Kingdom This Guarantee shall not cover the cost of any adjustment or adaptations to meet local voltage requirements and safety or other technical standards outside the United Kingdom where these differ from those applicable in the United Kingdom This Guarantee shall not apply to batteries or any other parts with
64. utput Voltages high 3V to 5V referred to signal ground low IV Output resistance 1000 short circuit proof Load resistance Greater than 10 Load capacitance Between 0 and 1000pF e g 10m of coax Test 1 Test 2 Inputs Logic high inactive 3V to 5V or open circuit Logic low active IV The above voltages are referenced to signal ground Page 55 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 APPENDIX A Summary Of Abbreviations Used In This Manual ASCII American Standard Code for Information Interchange PCI Power amp Communications Interface SIU Sensor Input Unit PRT Platinum Resistance Thermometer RS232 Communications standard RS422 Communications standard SoS Speed of Sound RCOM Gill Instruments Ltd PC communications software Optional Extras e PCI to anemometer cable available in a range of lengths e Sensor Input Unit e Additional connectors e Custom software on application Page 56 R3 amp R3A Doc No 1210 PS 0002 Issue 09 October 2004 APPENDIX B Principle Of Operation The basic time of flight operating principle is physically fundamental and provides vector measurement of air velocity dependent mainly on the dimensions and geometry of the transducer array Pairs of transducers act alternately as transmitters and receivers sending pulses of high frequency ultrasound between themselves The times of flight in each direction say tl and t2 are measured

Gill R3 & R3A Research Anemometers User Manual

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Gill R3 &amp; R3A Research Anemometers User Manual

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Gill R3 & R3A Research Anemometers User Manual