Gas detector Dual FPD

sulfurflame photometry

Bandpass filter for sulfur or phosphorous ( 1 per FPD ) Use the Dual FPD for simultaneous sulfur and phosphorous detection Detects sulfur compounds down to 200ppb, and phosphorous compounds down to 10ppb The Flame Photometric Detector can detect sulfur compounds, such as H2S or SO2, down to about 200 ppb and phosphorus compounds to 10 ppb. While not 100% selective, the FPD is 100,000 times more sensitive to sulfur and phosphorus compounds than hydrocarbons. The phosphorus response is linear, and the sulfur response is exponential (twice the sulfur yields four times the peak area). The FPD is similar in design to the FID, except that the detector body is light-tight and a second flow of hydrogen purges the optical path between the photomultiplier tube (PMT) and the hydrogen-rich flame. A bandpass filter (at 393 nm for sulfur and 525 nm for phosphorus) mounts in front of the PMT, so only that the emissions from sulfur or phosphorus are detected while other wavelengths are rejected. The dual FPD detector is equipped with two PMTs and filters for the simultaneous detection of sulfur and phosphorus.