User`s guide
USER'S GUIDE____________________________________________________________________ 
Absolute Humidity (DMP74A Probe 
Recommended) 
Measurement range (typical) 0.5 ... 100 g/m
3
(0.2 ... 40 gr/ft
3
) 
Accuracy  ± (0.2 g/m
3
 + 10 % of 
reading) 
± (0.1 gr/ft
3
 + 10 % of 
reading) 
Mixing Ratio (DMP74A Probe Recommended) 
Measurement range (typical) 0.2 ... 100 g/kg 
(2 ... 700 gr/lbs) 
Accuracy  ± (0.1 g/kg + 12 % of 
reading) 
± (0.8 gr/lbs + 12 % of 
reading) 
Relative Humidity (DMP74A) 
Measurement range  0 ... 100 % 
Accuracy at +20 ˚C 
RH < 5 %  ± (0.025 % RH + 17.5 % of 
reading) 
RH > 5 %  ± (0.8 % RH + 2 % of 
reading) 
Measurement Environment 
Temperature  -10 ... +60 ˚C (+14 ... +140 
˚F) 
Pressure 
DMP74A  0 ... 20 bar
a
 (0 ... 290 psi
a
) 
DMP74B  0 ... 20 bar
a
 (0 ... 290 psi
a
) 
DMP74C  0 ... 10 bar
a
 (0 ... 150 psi
a
) 
Sample flow rate  No effect on the dewpoint 
accuracy 
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