Model 482 High Gain Thermally Compensated Pyroelectric IR Detector

Model 482 consists of two lithium
tantalate sensing elements, a load
resistor and a JFET sealed into a TO-
18 transistor package with an optical
filter.
One centrally located sensing element
is exposed to infrared radiation
entering through the optical filter while
the second element is shielded from
outside radiation.
The sensing elements are connected
electrically in a parallel opposed
configuration for cancellation of
signals generated by both crystals due
to thermal changes in the housing environment.
The JFET circuit is configured to
provide gain (about 5x with a 100k