Barometric Pressure Sensor

Barometric pressure is measured using a Vaisala model PTB-101 instrument, which was discontinued for manufacturing in 2005 and for support in 2010. The replacement is the PTB-110 instrument. Each of these instruments has a version which measures in the range of 600 hecto Pascals (hPa) to 1060 hPa [1 hPa = 1 millibar], which is the span selected by UVMRP as most applicable to the range of elevations (-18 meters to +3397 meters) at our sites.

Barometers have been installed at only 14 sites, which include the seven sites – AK02, CA02, CO02, FL02, MD12, SK02, TX02 – chosen by NASA\Goddard for placement of the UVA instruments for use in their ground-truthing of satellite data. The other seven sites – CO12, CO97, HI02, NZ02, ON02, TX22, TX51 – were chosen because of the extensive amount of atmospheric science that is done using the data from these sites.

All but one barometer is mounted inside the UV-MFRSR enclosure, and is connected to the UV-MFRSR datalogger, so its output is measured every 20 seconds and integrated into 3-minute averages, and its data is retrieved nightly in conjunction with the polling of the UV-MFRSR datalogger. The exception is TX51, which is inside the vis-MFRSR enclosure and is at the 15 second sampling rate.