Maintenance, 3 calibration table – Vaisala HMD70 User Manual
Page 13
HMD70U/Y Transmitters
U303en-1.1
Operating Manual
1997-07-31
9
4.3
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
mA
5.81
5.81
5.81
5.81
0...20 mA
mA
2.26
2.26
2.26
2.26
0...1 V
V
0.113
0.113
0.113
0.113
0...5 V
V
0.565
0.565
0.565
0.565
0...10 V
V
1.13
1.13
1.13
1.13
NaCl
%RH
75.6
75.5
75.3
75.1
74.9
4...20 mA
mA
16.10
16.08
16.05
16.02
15.98
0...20 mA
mA
15.12
15.10
15.06
15.02
14.98
0...1 V
V
0.756
0.755
0.753
0.751
0.749
0...5 V
V
3.780
3.775
3.765
3.755
3.745
0...10 V
V
7.56
7.55
7.53
7.51
7.49
*)
LiCl solution must not be used or stored in temperatures below +18
°
C (+64
°
F);
otherwise the equilibrium humidity of the salt solution changes permanently
Table 1
Greenspan’s calibration table with output values according to
the chosen scale
5.
MAINTENANCE
5.1
Replacing the HUMICAP
180 sensor and the filter
Remove the damaged sensor and insert a new one. Handle the sensor by the
plastic socket. DO NOT TOUCH THE SENSOR PLATE. Recalibrate the
transmitter.
Replace a dirty filter (membrane or sintered) to ensure a maximum lifetime
and a fast response for the sensor. Do not try to clean the filter.