The LHi 1448 pyroelectric infrared detector is designed for high end PIR alarm applications. It includes a twin type pyro-electric ceramic with 4 sensitive elements connected to two FET source follower circuits.Thus it provides for dual channel output . Both channels are of the same polarity.
The LHi 1448 detector is available in TO-5 housing with standard infrared filter. It offers excellent common mode performance (match) and low noise.

Four elements in two pairs
Two outputs, equal polarity
Designed for PIR alarms