11
15A. Display Scaling for HX93DAC (all styles)
Your HX93DA transmitter comes with dual built-in LCD indicators for
displaying both Humidity and Temperature. Before the meter
adjustment or re-scaling can be done the transmitters current output
should be checked as per the calibration procedure in Section 12 and 13
to verify the display will be adjusted correctly and match the analog
output.
Relative Humidity Display Scaling
Recommended equipment:
• Humidity Calibration Kit, OMEGA
®
Model No.: HX92-CAL
• Handheld Digital Multi-meter, OMEGA
®
Model No.: HHM29
• Dc Power Supply, OMEGA
®
Model No.: PSU-93
1. Remove enclosure cover
2. Connect transmitter as shown in figure 6.
3. Apply power to transmitter and allow to warm up for 15 min.
4. Place unit in a 11% RH environment and allow to stabilize for 15 min.
5. Adjust potentiometer "ZERO" on the back of the RH display for a
reading of 11.0%
6. Place unit in a 75% RH environment and allow to stabilize for 15 min.
7. Adjust potentiometer "GAIN" on the back of the RH display for a
reading of 75.0%
8. Repeat steps 4, 5, 6, and 7 as necessary until proper readings are
maintained.
9. Re-scaling complete.
Figure 10 - Transmitter Lid Rear View
15A
HX93A, HX93DA SERIES
RH/Temperature Transmitter
Z
ZERO POTENTIOMETER
RELATIVE HUMIDITY
INDICATOR
TRANSMITTER LID REAR VIEW
TEMPERATURE
INDICATOR
GAIN POTENTIOMETER
ZERO POTENTIOMETER
GAIN POTENTIOMETER
Z
G
G
+
–
+
–