Photoionisation Lamps Are the Heart of Gas Detection Systems 

Heraeus Noblelight (Germany), one of the technology and market leaders in the field of specialty light sources, has published its latest application note on Photoionisation Detector Lamps (PID) lamps. PID lamps are at the heart of gas detection systems: why is a good PID lamp important and how to get the best out of it are explained in the latest application note. Lamp spectra, lifetime and the best practice for ensuring long term stability, plus why PID lamp quality is important are topics discussed. PID lamps are most commonly used in Hand-Held Gas Detectors for VOC detection, gas chromatography (GC), trace gas monitoring and sample ionisation for mass spectrometry.

“The purity of the spectrum is important for good lamp operation. The presence of secondary lines due to contaminants can affect the intensity of the primary lines, lamp intensity and lifetime”, explains Stephen Attwood, Sales Director of Heraeus Noblelight Analytics. However, contamination of the lamp can occur at higher wavelengths due in main to hydrocarbons. Whilst this does not interfere with the VUV lines in terms of detection of VOCs, the contamination absorbs some of the energy from those lines, resulting in decreased sensitivity and a shorter life time.