New Set of Coefficients
The SHTxx sensor output needs to be converted into humidity and temperature values. The Users Guide of the
datasheets SHT1x, V4.0 and SHT7x, V4.0, Chapter 4.1 each, give the following formula for calculating relative
humidity values:
2
RH 3 RH 2 1 linear
SO c SO c c RH ⋅ + ⋅ + = (%RH)
SORH stands for the digital sensor output – while cx is the set of coefficients. So far the set cx* was specified:
SORH c1* c2* c3*
12 bit -4.0000 0.0405 -2.8000E-6
8 bit -4.0000 0.6480 -7.2000E-4
These coefficients are still applicable for all SHTxx sensors – mainly for the version V3. Production data shows that
there is an optimized set of coefficients cx, that provide more safety margin within the specified limits:
13418555746
