DeFelsko PosiTector DPM Instruction Manual page 14

CAUTION:
To ensure optimal performance of your PosiTector DPM, do not
obstruct the airflow near the air temperature and humidity
sensors. Keep fingers away from the sensor, as body heat can
cause incorrect readings. Allow time for the instrument to
acclimate and for the readings to stabilize when moving the
instrument between different environments.
When using the surface temperature probe, do not use
excessive downward force, and do not drag it sideways. When
the instrument is not in use, place the rubber cap over the
surface temperature sensor to prevent damage.
12