Instruction Manual
HMP230 SERIES
M210225en-B User's Guide
59
• Wait at least 30 minutes.
• Connect an ammeter/voltmeter to the analogue outputs (connector
X2). Give command l¡¡¡. At the first calibration point the LED
on the left flashes; adjust the first point with the arrow switches to the
value given in the calibration table (Chapter 7.1.4) and press ENT
switch.
• Insert the sensor head into a measurement hole of the NaCl chamber.
• Wait at least 30 minutes.
• Check that the reading corresponds within the desired accuracy to that
given in the calibration table (Chapter 7.1.4). If not, adjust the second
point with the arrow switches to the correct value and press ENT. At
the second calibration point the second LED from the left flashes.
The basic capacitance of the new sensor may differ considerably from that of
the previous one. Therefore, the corresponding humidity reading of the
transmitter may be below 0 %RH at the low or above 100 %RH at the high
calibration point. However, the current/voltage reading of the analogue output
shows only the minimum or maximum value of the selected current/voltage
scale and the output value may not change even though the arrow switches are
pressed several times. If this happens, press the up or down arrow switch
continuously to bring the output back into the selected scale; this may take as
long as half a minute.
7.1.4. Humidity calibration table
Table 1 Greenspans's calibration table
Temperature °C 15 20 25 30 35
°F 59 68 77 86 95
LiCl %RH * 11.3 11.3 11.3 11.3
4...20 mA 5.81 5.81 5.81 5.81
0...20 mA 2.26 2.26 2.26 2.26
0...1 V 0.113 0.113 0.113 0.113
0...5 V 0.565 0.565 0.565 0.565
0...10 V 1.13 1.13 1.13 1.13
NaCl %RH 75.6 75.5 75.3 75.1 74.9
4...20 mA 16.10 16.08 16.05 16.02 15.98
0...20 mA 15.12 15.10 15.06 15.02 14.98
0...1 V 0.756 0.755 0.753 0.751 0.749
0...5 V 3.780 3.775 3.765 3.755 3.745
0...10 V 7.56 7.55 7.53 7.51 7.49
*) If the LiCl solution is used or stored at temperatures below +18 °C
(+64 °F), the equilibrium humidity of the salt solution changes
permanently.