0
0.1
0.2
0.3
0.4
Accuracy [± °C]
Temperature [°C]
-40
-30
-20
-10
0
10
20
30
40
50
60
0.5
Figure 34 HMP1 temperature measurement accuracy over full range
Table 7 HMP1 operating environment
Property Description/Value
Operating temperature −40 … +60 °C (−40 … +140 °F)
Storage temperature −40 … +60 °C (−40 … +140 °F)
Measurement environment For air, nitrogen, hydrogen, argon, helium, and
oxygen
1)
IP rating IP50: Limited protection against dust
1) Consult Vaisala if other chemicals are present. Consider safety regulations with flammable
gases.
Table 8 HMP1 inputs and outputs
Property Description/Value
Operating voltage 15 … 30 V DC
Current consumption 2 mA typical, 200 mA max.
Digital output RS-485, non-isolated
Protocol Modbus RTU
Table 9 HMP1 output parameters
Output parameter name and unit
Absolute humidity (g/m
3
)
Relative humidity (%RH)
Absolute humidity at NTP (g/m
3
)
Relative humidity (dew/frost) (%RH)
Dew point temperature (°C) Temperature (°C)
Chapter 9 – Technical data
65