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 separately. Specifications Meteolabor TP3-ST (content coming soon) HMP45C 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 Platform Compatibility These sensors are highly modified and embedded in the ECO-Dimona's MET System (part of the EF19B sensor package). Availability We have 1 of these highly modified systems. This article was published on 2024-06-25
