HMP75, HMP76, and HMP77 specifications - HM70

HM70 User Guide

Document code
M210297EN
Revision
G
Language
English (United States)
Product
HM70
Document type
User guide
Table 1. HMP75, HMP76, and HMP77 measurement performance
Property Description/Value
Relative humidity
Measurement range 0 … 100 %RH
Accuracy: 1 2
At +15 … +25 °C (+59 … +77 °F)

±1 %RH (0 … 90 %RH)

±1.7 %RH (90 … 100 %RH)

At −20 … +40 °C (−4 … +104 °F) ±(1.0 + 0.008 x reading) %RH
At −40 … +180 °C (−40 … +356 °F) ±(1.5 + 0.015 x reading) %RH
Factory calibration uncertainty (+20 °C / +68 °F)

±0.6 %RH (0 … 40 %RH)

±1.0 %RH (40 … 97 %RH)

Response time (90%) at +20 °C (+68 °F) in still air:
HMP75 (with standard plastic grid) 17 s
HMP76 (with standard sintered bronze filter) 60 s
HMP77 (with standard plastic grid and stainless steel netting) 50 s
Typical long-term stability Better than 1 %RH / year
Temperature
HMP75 measurement range −20 … +60 °C (−4 … +140 °F)
HMP76 measurement range −50 … +120 °C (−58 … +248 °F)
HMP76 short time measurement range −50 … +180 °C (−58 … +356 °F)
HMP77 measurement range −70 … +180 °C (−94 … +356 °F)
Accuracy at +20 °C (+68 °F) ±0.2 °C (±0.36 °F), see the graph below
Output parameters
Dew point, frost point, absolute humidity, mixing ratio, wet bulb temperature, water content, vapor pressure, saturation vapor pressure, enthalpy, water activity
Figure 1. Temperature measurement accuracy over temperature range
Table 2. Calculated parameters
Property Description/Value
Typical measurement range
Dew point temperature −20 … +100 ºC (−4 … +212 ºF)
Mixing ratio 0 … 600 g/kg dry air
Absolute humidity 0 … 600 g/m3
Wet bulb temperature 0 … +100 ºC (32 … +212 ºF)
Enthalpy 0 … 160 kJ/g
Water vapor pressure 0 … 1000 hPa
Accuracy
Accuracies of the calculated parameters depend on the calibration accuracy of the humidity and temperature sensors; here the accuracies are given for ±2 %RH and ±0.2 °C.
Figure 2. Accuracy of dew point temperature °C
Figure 3. Accuracy of mixing ratio g/kg (ambient pressure 1013 mbar)
Figure 4. Accuracy of wet bulb temperature °C
Figure 5. Accuracy of absolute humidity g/m3
Table 3. HMP75, HMP76, and HMP77 general specifications
Property Description/Value
Humidity sensor

HUMICAP® 180R

HUMICAP® 180RC (chemical purge, sensor preheat)

Temperature sensor Pt100 RTD Class F0.1 IEC 60751
Operating temperature range for electronics −40 … +60 °C (−40 … +140 °F)
Standard sensor protection
HMP75 Plastic grid
HMP76 Sintered bronze filter
HMP77 Grid with SS netting
Table 4. HMP75, HMP76, and HMP77 mechanical specifications
Property Description/Value
IP rating IP65 (NEMA 4)
Housing material ABS/PC blend
Probe material Stainless steel (AIS316L)
Probe cable length (between indicator and probe handle) 1.9 m (6.2 ft)
Probe cable length of HMP77 (from handle to the root of probe) 5.0 m (16 ft)
Probe diameter 12 mm (0.47 in)
Weight
HMP75 250 g (8.8 oz)
HMP76 350 g (12 oz)
HMP77 500 g (18 oz)
1 Including non-linearity, hysteresis, and repeatability.
2 Defined as ±2 standard deviation limits.