Vaisala HMT120 - Manual (Page 56)

User's Guide _______________________________________________________________________
54 ___________________________________________________________________ M211244EN-B
Adjustment with HM70
You can check and adjust the HMT120 relative humidity measurement
with the HM70 Hand-Held Humidity and Temperature meter. A HM70-
connection cable is needed. Vaisala order code: 211339.
There are four types of adjustments available: field checking and
adjustment using a calibrated reference probe, one-point adjustment
using a calibrator, two-point adjustment using a calibrator, and LiCl-
NaCl adjustment.
Follow the first seven steps and continue according to the chosen
adjustment method.
0505-351
Figure 17 Location of the MI70 Probe and Cable Connector
Ports
1. Connect the 211339 HM70-connection cable to the SERVICE PORT
connector on the HMT120 motherboard (see Figure 11 on page
21).
2. Connect the other end of the connection cable to either of the
HM70's connector ports located on the bottom of the indicator (see
Figure 17 above).
3. Turn on both devices (or just HM70, in case that HMT120 is on
continuously).
4. Check that the transmitter reading is shown on the indicator. The
reading of the transmitter is shown on the top or middle row of the
display, depending on which connector port the connection cable is
connected to.
5. Press the ADJ button on the HMT120 motherboard to open the
adjustment mode. Both LEDs on HMT120 motherboard remain in
OFF state and text "Starting adjustment mode for HMP110" is
shown at the MI70 display.
NOTE In case of using a HMT120 transmitter with display option, text "MI70
adjustment mode" is shown on the upper row of HMT120 display.