Chapter 5 _______________________________________________________________ Calibration
CHAPTER 5
CALIBRATION
This chapter contains information that is needed to calibrate this product.
Vaisala recommends a recalibration of the HMM212 module after six
months of use. After the first recalibration, the recommended calibration
interval is approximately 12 months. However, please note that these
intervals depend on the operating conditions and the required accuracy.
When calibrating humidity instruments, it is important that the probe, the
reference instrument, and the calibrator are in thermal equilibrium.
Therefore, always allow enough time for stabilization before starting the
actual calibration.
- Calibration in the chamber: leave the calibrator (for example, the
HMK15) in the chamber overnight with the chamber door open.
- Calibration of a humidity and temperature module: allow at least one
hour for the stabilization of the calibrator (for example, HMI41 with a
reference probe).
One-Point Humidity Calibration
With the HMI41 Indicator and Calibration
Cable
You can calibrate the HMM212 module with the HMI41 indicator and an
appropriate calibration cable (19164ZZ). Connect the cable to the test
connector of the HMM212 module and insert the jumper as indicated in
Figure 4 on page 22. For detailed instructions, see the following
documents:
- Vaisala
HUMICAP
®
Indicator HMI41 and Probes HMP41/45/46
User's Guide
- Calibration of Digital Transmitters with Vaisala HUMICAP
®
Humidity Indicator HMI41 Cables 19164ZZ and 25917ZZ User's
Guide
VAISALA _______________________________________________________________________ 21
