Vaisala HMP155 - Manual (Page 76)

USER'S GUIDE____________________________________________________________________
74 _______________________________________________________________ M210912EN-C
Calculated Variables
Table 19 Calculated Variables
Quantity Abbreviation Metric Unit Non Metric
Unit
Dew point / Frost point
Temperature (T
d/f
)
TDF ºC ºF
Dew point Temperature (T
d
) TD ºC ºF
Mixing ratio (x) X g/kg gr/lbs.
Wetbulb temperature (T
w
) TW ºC ºF
Accuracies of Calculated Variables
Accuracies of the calculated variables depend on the calibration accuracy
of the humidity and temperature sensors; here the accuracies are given
for ± 2 %RH and ± 0.2 °C.
Accuracy of Dew point Temperature °C
Relative humidity
Temp. 10 20 30 40 50 60 70 80 90 100
-40 1.86 1.03 0.76 0.63 0.55 0.50 0.46 0.43 — —
-20 2.18 1.19 0.88 0.72 0.62 0.56 0.51 0.48 — —
0 2.51 1.37 1.00 0.81 0.70 0.63 0.57 0.53 0.50 0.48
20 2.87 1.56 1.13 0.92 0.79 0.70 0.64 0.59 0.55 0.53
40 3.24 1.76 1.27 1.03 0.88 0.78 0.71 0.65 0.61 0.58
60 3.60 1.96 1.42 1.14 0.97 0.86 0.78 0.72 0.67 0.64
Accuracy of Mixing Ratio g/kg (Ambient
Pressure 1013 mbar)
Relative humidity
Temp. 10 20 30 40 50 60 70 80 90 100
-40 0.003 0.003 0.003 0.003 0.003 0.004 0.004 0.004 — —
-20 0.017 0.018 0.019 0.021 0.022 0.023 0.025 0.026 — —
0 0.08 0.09 0.09 0.10 0.10 0.11 0.11 0.12 0.13 0.13
20 0.31 0.33 0.35 0.37 0.39 0.41 0.43 0.45 0.47 0.49
40 0.97 1.03 1.10 1.17 1.24 1.31 1.38 1.46 1.54 1.62
60 2.68 2.91 3.16 3.43 3.72 4.04 4.38 4.75 5.15 5.58