User manual

MetPak Doc No 1575-PS-0001 Issue 02 CN 4240 March 2006
3.3 Temperature and Relative Humidity Sensor
Two types of temperature and humidity probes are available dependant on the option ordered.
Campbell CS215 temperature and relative humidity probe.
The CS215 probe utilises a novel single chip element that incorporates both a temperature and RH sensor. Each element
is individually calibrated with the calibration corrections stored on chip. The element is easily changed in the field.
Replacement of the element effectively fully recalibrates the probe both for temperature and humidity thus minimising
downtime and calibration costs.
Low power electronics within the CS215 controls the measurement made by the sensor element, applies temperature and
linearization corrections to the readings and presents the data via an SDI-12 compatible interface to a datalogger.
The probe is fitted with a custom-made, yet low-cost sintered plastic filter to minimise the effects of dust and dirt on the
sensor. The filter is lightweight and hydrophobic thereby minimising the effect of the time response of the sensor.
The probe housing is designed to withstand permanent exposure to all weathers and to fit into a range of radiation
shields including lower cost compact shields.
Rotronic HygroClip.
The HygroClip modules are complete instruments, with integrated temperature compensation and highly flexible power
requirements. Calibration data is maintained within the integrated electronics. It provides linear analogue output signals
for % rh and °C.
Fig 3 Position of Temperature and Relative
Humidity Probe in the Radiation Shield
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