INFRARED
REAL-TIME MEASUREMENTS OF GASES IN A MIXTURE
Our Infrared ( IR ) sensors focus an IR light source through a sample cell holding a continuously flowing sample of the gas mixture , and onto a detector after wavelength selection .
The property of some gases to absorb unique light wavelengths can be used to detect the concentration of a selected gas in a mixture .
Depending on the intended application , this concept can be applied in two ways :
SINGLE BEAM , SINGLE WAVELENGTH ( SBSW )
Delivers fast , stable and accurate realtime measurements with low maintenance requirements . It is used where a small transducer is required – the IR light source is electronically modulated , removing the need for a motor and rotating filters .
SINGLE BEAM , DUAL WAVELENGTH ( SBDW )
Uses a pair of optical filters mounted on a rotating disc , which pass through a beam of IR light alternately . One filter ( the measure filter ) is chosen to pass light only at a wavelength that the gas to be measured absorbs , while the other filter ( the reference filter ) has a light passed through it at a wavelength unaffected by the gas to be measured . The difference in absorbance is measured by the detector and provides a direct output of the gas concentration .
SERVOTOUGH SpectraExact 2500
P82