User manual VAISALA HMP240

[. . . ] HMP240 SERIES TRANSMITTERS User's Guide M210300en-A June 2002 ©Vaisala Oyj 2002 No part of this document may be reproduced in any form or by any means, electronic or mechanical (including photocopying), nor may its contents be communicated to a third party without a prior written notice of the copyright holder. The instruction manuals may be changed without prior notice. M210300en HMP240 series User's guide Contents 1. PRODUCT DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 ADVANTAGES OF A WARMED SENSOR HEAD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3. 1 3. 2 Selecting the place of installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3. 2. 1 Mounting the HMP243. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3. 2. 2 Mounting the HMP247. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] If necessary, change the second point reading with the arrow keys and press ENT. With LED commands Leave the reference instrument and the transmitter for at least 4 hours in the same space so that their temperatures have time to equalize. Remove the filter cap prior to calibration. Disconnect the security lock jumper! · · · 6. 2. 2. 3 · · · Check the transmitter against the reference. Connect an ammeter/voltmeter to the analogue outputs (connector X2). Give command ¡¡l¡ (or ¡l¡¡ for the T sensor head). At the first calibration point the LED on the left flashes; adjust the first point (offset) with the arrow switches to the same reading with the reference and press ENT switch. Change the temperature and check the transmitter again against the reference. Check that the reading corresponds to the reading of the reference instrument. If necessary, adjust with the arrow switches to the correct value and press ENT. At the second calibration point the second LED from the left flashes. · · · 53 HMP240 User's Guide M210300en 6. 3 Calibration of analogue outputs The analogue outputs have been calibrated at the factory and since they are very stable, calibration should be performed only when there is reason to believe that their adjustments have changed. 6. 3. 1 With serial commands Disconnect the security lock jumper!ACAL <cr> The outputs on channels 1 and 2 are measured and the measured values (mA or V) entered as calibration coefficients. Example: both channels have 0. . . 10 V outputs (set with AMODE command); enter the voltages measured at the analogue outputs: >ACAL <cr> Ch1 U1 ( V Ch1 U2 ( V Ch2 U1 ( V Ch2 U2 ( V ) ) ) ) ?0. 123 <cr> 9. 98 <cr> 0. 120 <cr> 9. 98 <cr> 6. 3. 2 With display / keypad commands Disconnect the security lock jumper! · Connect an ammeter/voltmeter to the output of channel 1, select Cali in the main menu and Analog outputs in the Cali menu. The following is displayed (the quantity can be either mA or V): · Enter the measured lower end current/voltage on channel 1: · Enter the measured upper end current/voltage on channel 1: · Connect the meter to the output of channel 2 and enter the measured lower end current/voltage on channel 2: 54 M210300en HMP240 series User's Guide · Enter the measured upper end current/voltage on channel 2. 6. 3. 3 With LED commands If both the analogue outputs and humidity/temperature channels are calibrated, the analogue outputs should be calibrated first. This applies only when the calibrations are done with LED commands! · connect an ammeter/voltmeter to the analogue outputs (connector X2) Disconnect the security lock jumper! · · · · · Give command ¡¡ll. the LED on the left flashes; set the low end of channel 1 with the arrow keys and press ENT the second LED from the left flashes; set the high end of channel 1 with the arrow keys and press ENT the LED on the left flashes; set the low end of channel 2 with the arrow keys and press ENT the second LED from the left flashes; set the high end of channel 2 with the arrow keys and press ENT The analogue outputs are calibrated to ensure the correct scaling: for example, when the output is scaled to 4. . . 20 mA, the low end of the scale is 4 mA and high end 20 mA exactly. 20 mA output is used, the output can not be adjusted to exactly 0 mA, but to 50 µA. When 0. . . 1 V, 0. . . 5 V or 0. . . 10 V output is in use, the output is adjusted to 50 mV. The following table summarizes the correct output values. Summary of the correct output values: Output scale: 0. . . 20 mA 4. . . 20 mA 50 µA 4 mA 20 mA 20 mA low end: high end: 0. . . 1 V 50 mV 1V 0. . . 5 V 50 mV 5V 0. . . 10 V 50 mV 10 V 55 HMP240 User's Guide M210300en 7. 7. 1 MAINTENANCE Reference measurements Reference measurements are necessary for the verification of whether the transmitter readings are within specifications. This way the user can check if the transmitter needs calibration or service. [. . . ] Otherwise the transmitter starts re-gaining with new parameters only when the old re-gaining interval is completed. 123 HMP240 Appendix 7: Re-gaining M210300en Use arrow keys to change the status of the automatic re-gaining and press ENT. Acknowledge the current setting by pressing ENT. Select the new time interval digit by digit with the arrow keys and acknowledge each digit with ENT key. With CL key you can correct the entry by deleting the digits one by one. When you have entered the whole time interval, press ENT for the second time. Other re-gaining parameters are acknowledged or changed the same way. [. . . ]