Pyroelectric detectors are susceptible to line interference and other sources of electromagnetic interference from non-detector related noise. Several manufacturers of OEM sensor devices use EMI filters to prevent these noise sources interfering with the operation of the device but for many gas detection applications a higher level of noise immunity is required.
LASER COMPONENTS has developed a new pyroelectric detector using a differential mode of operation ensuring that external pick up is eliminated greatly improving the electromagnetic immunity of the device. Pyroelectric crystals generate positive and negative charges on opposite faces of the crystal and using appropriate amplifi cation can generate a differential signal.
Differential operation results in a significant increase of the signal to noise ratio, this is because the output signal is doubled with this configuration while the noise only grows as the square root, the improvement in signal to noise is approximately 1.41 over a standard single ended pyroelectric detector.
The R&D team at LASER COMPONENTS designed our LD2100 with its use in electrically noisy environments in mind. These devices are used in NDIR and FTIR spectroscopy as well as flame and fire detection. The devices are inexpensive, robust and highly sensitive in the IR region of the spectrum.