The Thermo Scientific GM-5000 Air Quality Monitor draws sample through a screen and heated tube, minimizing larger particles and excess moisture and allowing gaseous pollutants and particulate matter to be detected. For units configured with both gas and particulate measurement, the sample enters a laser based optical particle counter (OPC) that detects both the number of particles and the particle size distribution. The factory calibration calculates the approximate mass concentration.
The sample continues through a small fan and filter and enters the gas sensing chamber. The concentration of the four standard gases are measured by electrochemical cells and the concentration is calculated. The measurement for both particulate and gas, as well as sample stream temperature, pressure, relative humidity, and date/time stamp, are sent to a web server running on the instruments embedded computer and transmitted through a 3G/4G modem as well as a local WiFi dongle. The data may be viewed on a computer, tablet or phone running a standard browser. The same data is stored locally on a micro SD card and may be retrieved through the browser.