TECHNICAL
2
DATA
M
EASUREMENT
C
ONDITIONS
G
HTM2500 is specified for accurate measurements
within 10 to 95% RH.
G
Excursion out of this range (< 10% or > 95% RH,
including condensation) does not affect the reliability
of HTM2500 characteristics.
Output Voltage (mV)
HTM 2500 Typical Measuring Ranges in Humidity
4000
3500
3000
METROLOGY
HTM 2500 RANGE
2500
2000
1500
1000
0
10
20
30
40
50
60
70
80
90
100
Relative Humidity in %
HTM2500 M
ODELLED
L
INEAR
V
OLTAGE
O
UTPUT
(V
S
= 5V)
4000
REFERENCE OUTPUT VALUES
RH (%) V
out
(mV) RH (%) V
out
(mV)
1235
10
2480
55
1390
15
2605
60
1540
20
2730
65
1685
25
2860
70
1825
30
2990
75
1960
35
3125
80
2090
40
3260
85
2220
45
3405
90
2350
50
3555
95
3500
Output Voltage (mV)
3000
2500
2000
1500
Vout = 26.65 RH + 1006
from 10 to 95 % RH
with Vout in mV and RH in %
1000
0
10
20
30
40
50
60
70
80
90
100
Relative Humidity in % RH
Reversed Polynomial Equation
Vout = 1.05E-3RH3 -1.76E-1RH2 + 35.2RH + 898.6
E
RROR
B
UDGET AT
23°C
6
5
4
HTM2500 ERROR LIMITS
Delta in % RH
3
2
1
0
-1
-2
-3
-4
-5
-6
0
10
20
30
40
50
60
70
80
90
100
Temperature coefficient compensation
RH
Cor
% = RH%
Read
* (1 -(Ta -23)* 2.4E-3)
Relative Humidity in % RH
2
1.5
Non linearity and temperature compensation
RH% = -1.9206E-9V 3 + 1.437E-5V
out
2
+ 3.421E-3V
out
- 12.4
out
Delta in % RH
1
0.5
0
-0.5
-1
-1.5
-2
0
10
20
30
40
50
60
70
80
90
100
1 + (Ta-23) * 2.4E-3
All equations V
out
in mV, RH in %, Ta in °C.
Relative Humidity in % RH
LINEARITY ERROR OF HTM2500
HPC032 Rev. B Jul 2002
HUMIREL [ Humirel ]
