1. Introduction
The HMP155A probe monitors relative humidity (RH) for the range of 0 to 100% RH and
temperature for the range of –80 to 60°C. It provides reliable measurements for a wide range of
applications as part of a weather station system or as a single instrument. All Campbell Scientific
data loggers are compatible.
NOTE:
This manual provides information only for CRBasic data loggers. For retired Edlog data logger
support, see an older manual at www.campbellsci.com/old-manuals .
2. Precautions
lREAD AND UNDERSTAND the Safety section at the back of this manual.
lCare should be taken when opening the shipping package to not damage or cut the cable
jacket. If damage to the cable is suspected, contact Campbell Scientific.
lAlthough the HMP155A is rugged, it should be handled as a precision scientific instrument.
lDo not touch the sensor element.
lSantoprene® rubber, which composes the black outer jacket of the cable, will support
combustion in air. It is used because of its resistance to temperature extremes, moisture,
and UV degradation. It is rated as slow burning when tested according to U.L. 94 H.B. and
passes FMVSS302. However, local fire codes may preclude its use inside buildings.
3. Initial inspection
lUpon receipt of the HMP155A, inspect the packaging and contents for damage. File
damage claims with the shipping company.
lThe model number and cable length are printed on a label at the connection end of the
cable. Check this information against the shipping documents to ensure the expected
product and cable length were received.
HMP155A Temperature and Relative Humidity Probe 1
