Modified Meteolabor TP3-ST dewpoint and Viasala HMP45C relative humidity sensors form the core of a dedicated humidity sensing system.
The humidity system sensors are enclosed within the main MET system enclosure and aspirated via a small pump and flow controller. The sensors are temperature stabilised to prevent condensation and to reduce the number of variables affecting performance, and are maintained at a slight positive pressure to prevent entrainment of local air.
The principle sensors employed are:
Meteolabor TP3-ST chilled mirror dewpoint hygrometer
Viasala HMP45C relative humidity sensor
Pressure in each sensor housing is measured to allow us to calculate the mixing ratio; Druck RPT410F pressure sensors are used for this.
A Licor 7500 open path gas analyser, and a Picarro G2301m CRDS analyser also provide humidity measurements, but are described seperately.
For more detail information please refer to the instrument manuals and datasheets.
(content coming soon)
Operating temperature: -40C to +60C
Storage temperature: -40C to +80C
Supply Volatge: 7 to 35 VDC
Power consumption: <4mA @ 12 VDC
Humidity Accuracy @ 20C: +/- 2% RH (0-90%RH); +/-3% RH (90-100% RH)
Temp. Dependence of RH Measurement: +/-0.05%RH/degree C
Response time at 20C, 90% response: 15s with filter
Long term stability: <1%RH per year