|The Sensirion SHT1x is a smart
sensor for both humidity and temperature, and it comes from the factory
in a tiny package that incorporates the analog to digital interface.
Humidity is notoriously difficult to measure. Some of the scientific
and electronic considerations to measuring humidity include: analog to
digital interface and external circuitry which might require op-amps or
oscillator circuitry; temperature compensation adjustments to calculate
dew point; calibration against a known humidity source; mounting,
protection and response time in the real-world.
The Sensirion SHT1x addresses
many of these issues head on. It is a smart sensor for both humidity and
temperature, and it comes from the factory in a tiny package that
incorporates the analog to digital interface. All that the BASIC Stamp
has to do is read out the humidity and temperature values through the
two-wire digital serial interface. The only math required is a simple
scale and offset. The SHT1x is factory calibrated so that it returns
temperature with a resolution of 0.01 degrees Celsius and relative
humidity with a resolution of 0.03 percent. The accuracy is better than
most other sensors too. Worst-case temperature accuracy is +/- 2 degrees
C - but in the "room temperature" range the accuracy better
than +/- 1 degree C. The relative humidity sensor is similarly accurate:
+/- 3.5% in the range 20% to 80%. This is quite remarkable for a
low-cost sensor. Excellent for commercial or home-based projects that
require such readings.