I decided to look at the Eltec Pyroelectric detector IR-Eye 442-3 Integrated Sensor from Acroname. It detects infrared radiation (IR) which is electromagnetic radiation with a wavelength is longer than that of visible light. IR is generated by objects that generate heat. The sensor is able to detect people or objects and be can be used for purposes such as intrusion detection, lighting control, robotics, motion sensing, automatic door control, or safety warning.

Pyroelectric charge is the electric charge that is created in response to infrared radiation. This particular sensor uses lithium tantalate, which Wikopedia defines as a “material similar to lithium niobate, possesses unique optical, piezoelectric and pyroelectric properties which make it valuable for motion detectors, cell phones and possibly nuclear fusion”.

If I understand it correctly, the sensor looks not for a certain temperature, but rather for a difference or jump in temperature. [Is this what “Parallel Opposed Dual IR Detector” means?] This becomes a problem when the person or object you are trying to detect remains motionless- they essentially “disappear” or fade into the background and the sensor is unable to see them. This can be addressed by having the sensor move back and forth in a sweeping motion.

This sensor is small & circular. It measures .36″ in diameter.
It has 4 pins: power, output, reference voltage, and ground.
It operates with a range of 5 to 15 volts with a maximum current of 2.2 milliAmps.
The field of view ranges between 30-60 degrees, making it extremely directional.
It has a temperature range of -40 to +70 degrees Celcius.
An internal OpAmp provides 100x signal amplification.


Examples of use:

What is…
parallel opposed
integrated analog signal processing
high gain
burn-in test
common mode rejection

Comments are closed.