To calibrate your HMP60 or HMP110 series probe, you need a known stable humidity or temperature reference, and a way to read the output of the probe (Vaisala Insight software, analog output, serial output, the MI70 indicator, or the HM40 meter). As a humidity reference you can use, for example, the Vaisala Humidity Calibrator HMK15.
The probe can be connected to a PC with Vaisala USB cable 219690, and to the MI70 indicator with connection cable 219980. The HM40 meter does not need a specific connection cable.
|The probe cannot be used with the MI70 handheld indicator or the HM40 meter when the probe is in analog mode. To use the probe with MI70 or HM40, enable a serial mode (for example, STOP) in Vaisala Insight software. Use Insight also to return the probe to analog mode.|
Connect the MI70 connection cable, the HM40 meter, or the USB cable to the HMP60/HMP110 probe.
- With MI70: Connect the other end of the connection cable to the MI70 indicator.
- With Insight: Leave the other end of the USB cable unconnected at this point. You can connect it to the PC after the stabilization period (4).
- Remove the filter from the probe and place the probe in the reference environment. For example, you can use a NaCl salt chamber (75 %RH) as the humidity reference.
Wait for 20 ... 40 minutes for the reading to stabilize. Do not touch the probe or breathe in its direction during this time.
- If you are using the MI70 indicator or the HM40 meter, you can follow the stabilization using the graph functionality.
- If you are using the USB cable, do not keep the cable connected to the PC during the stabilization period for best calibration accuracy.
After the stabilization period:
- With MI70/HM40: Switch MI70/HM40 off and on to start a blank graph.
- With Insight: Connect the USB cable to the PC and start the Insight application.
- Wait for 1 minute and make sure the graph showing the measurement reading is stable.
- Check the measurement reading, and compare it with the reading shown by the humidity or temperature reference.