How and where should sensors be fitted and maintained?
Temperature and humidity sensors
General advice is required for cleaning and maintaining temperature and humidity sensors.
The most important thing about sensors is to fit them correctly and appropriately during installation as this will reduce the amount of maintenance required. Fit them in locations that are accessible as well as away from dust and dirt to reduce the amount of cleaning required. See Recommended locations for Temperature Sensors, Valves, and Actuators for further advice on sensor location.
Check the specific installation instructions for the sensor used and verify they are fitted accordance with this.
All sensors should be regularly checked for correct operation as part of a regular building maintenance plan and replaced if they are not operating correctly.
Most sensors are sealed units and do not require maintenance, maybe just an occasional dust with a clean cloth to remove surface dust, these include duct and immersion temperature sensors, outdoor sensors and thermostats.
Room temperature and humidity sensors usually have vents or gauzes to allow airflow over the elements; these should be regularly dusted and can be cleaned with careful use of a vacuum cleaner or air blower to remove dust or other particles from within the unit. Do not however use equipment that can produce excessive pressures like compressed airlines as this could result in damage to the sensor.
If you do need to use cleaning products on the sensors, then first check the materials used on that specific sensor (see datasheet, most sensors use Polycarbonate or ABS plastics) then verify that the cleaning chemicals are safe for use on that type of plastic or metal.
Chemical/ material compatibility data is widely available on external websites (e.g. http://www.coleparmer.co.uk/Chemical-Resistance )