Adjusting Output Using Trimmers and Reference Transmitter (1-point adjustment) - HMD60 - HMD62 - TMD60 - TMD62

HMD62 TMD62 User Guide

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  • A recently calibrated reference device (for example, a second HMD60 transmitter).
  • A multimeter for checking the analog output reading (connect in series to measure the current output).
  • Small Phillips head screwdriver for turning the trimmers.
It is assumed that a hole was drilled for the reference instrument during installation, the transmitter is powered, and you can view the measurement output value.
To adjust the output:
  1. Insert the reference transmitter into the measurement environment next to the transmitter that you are adjusting.
    The reference transmitter should be inserted approximately 30 cm (12 in) from the HMD60 probe's installation hole, towards the direction of the air flow. See Figure 1.
  2. Connect a multimeter to the analog output of the reference transmitter (connect in series to measure the current output).
  3. Wait for the measurement to stabilize fully. This may take more than 30 minutes. Monitor the readings to see when the measurement has stabilized.
  4. When the measurement has stabilized, adjust the output of your transmitter with the trimmers until it matches the output of the reference transmitter.
    Note that there is a small delay before the output value updates after turning the trimmer.
  5. When done, plug the installation hole of the reference transmitter.