Pyroelectric infrared sensor?

Question

Does anyone know what range of distances these can work off of.
I have heard several inches but I was hoping for something further then that.

Answer 1

I suspect you are referring to what we use to fondly call "purple-peepers". They were used to detect pilot lights in large furnaces and boilers. They worked O.K. inside of twelve inches and if adjusted carefully could work up to 18 inches but had to be adjusted before every start-up because of heat distortions. If peepers did not detect a pilot flame the logic's automatically sent the whole operation back through a purge process. That could be time consuming. They were also used to detect a main flame on a timer basis. Anyway 12 to 18 inches and realign after every use. Maybe they have better one today (hopefully)..

Answer 2

I don't know what you mean by a pyroelectric infrared sensor.

I have worked with successful IR flame sensors that could see many feet. One that unfortunately could see a welder at a quarter of a mile.

One military sensor can see a one-inch cube at 1500 degrees F at a distance of 1500 miles.

Another that can see a man at over 26 miles.

Maybe an explanation of what you want an IR sensor to do would help us answer your question better.