Non-Dispersive Infrared (NDIR) spectroscopy is by far the most common gas detection method used today. Infra-red radiation generated by a broad band emitter is passed through the gas which is contained in a measurement cell. The advantage of NDIR comes from the strength of absorption in the mid IR compared to methods based on near infra-red spectroscopy. The strong absorption allows relatively low concentrations of gas to be detected with small path lengths and inexpensive components.
In order to measure gases at particularly small concentrations or very quickly, a high sensitivity detector is required. Differential pyro devices with responsivities of 240,000V/W are suitable for this fit and forget application.
LASER COMPONENTS manufactures a range of innovative differential pyroelectric detectors at our factory in Florida. The LD2120 has an in built differential amplifier within the
housing generating a signal with a 1.41 improvement in signal to noise over a standard pyroelectric detector.
From our office in the UK we can also supply broad band emitters for this application. The EP range is a pulsable device using a tungsten filament to achieve an operating temperature of 1900K. The emitters are housed in a TO8 package and are fitted with a gold plated parabolic reflector as standard.