Product Overview

Theory of operation
The humidity element is a capacitive sensor. The plates
encase a water-permeable polymer that changes its
dielectric constant through absorption of moisture in the
air. The humidity-induced change in capacitance is used
to produce a voltage signal proportional to the relative
humidity of the sensed air.
Table 1: Nominal values for nickel and platinum
sensors
Temperature Resistance (ohm)
°F °C Nickel Platinum
-50 -45.6 673.7 820.7
-40 -40 699.0 842.7
-30 -34.4 724.6 864.7
-20 -28.9 750.5 886.6
-10 -23.3 776.8 908.5
0 -17.8 803.5 930.3
10 -12.2 830.4 952.1
20 -6.7 857.8 973.9
30 -1.1 885.5 995.7
40 4.4 913.5 1017.4
50 10.0 942.0 1039.0
60 15.6 970.8 1060.7
70 21.1 1000.0 1082.3
80 26.7 1029.6 1103.8
90 32.2 1059.6 1125.3
100 37.8 1089.9 1146.8
110 43.3 1120.7 1168.3
120 48.9 1151.9 1189.7
130 54.4 1183.5 1211.1
140 60.0 1215.6 1232.4
150 65.6 1248.0 1253.7
160 71.1 1280.9 1275.0
170 76.7 1314.2 1296.2
180 82.2 1348.0 1317.4
190 87.8 1382.2 1338.6
200 93.3 1416.8 1359.7
210 98.9 1451.9 1380.8
220 104.4 1487.5 1401.9
See Figure 2 for nickel and platinum sensor R/T response
characteristics.
Figure 2: Nickel and platinum temperature response
Ordering information
To order a HE-69xx Duct Probe Humidity and Temperature
Sensor, contact the nearest Johnson Controls
representative.
Note: See Table 3 for a list of available models.
Repair information
If the HE-69xx Duct Probe Sensor fails to operate within its
specifications, replace the unit. For a replacement sensor,
contact the nearest Johnson Controls
®
representative.
HE-69xx Series Duct Probe Humidity and Temperature Sensors Product Bulletin2