IR Temperature Detection with sensitivty of 1 degree - possible?

[MIMSAR]

Hi,

I'm trying to design a system which will be able to detect a hot object on a cold surface. The downside is the temperature difference is only 1 degree celcius and I'd like to use IR from a distance of about 10cm (further away preferred if possible).

Does anyone with any experience of this know a suitable sensor or system I could use please. I'm guessing some form of calibration will be needed to tell the sytem the temperature of the cold surface first.

Thanks,

 

[ronv]

What are the sizes of the two? What temperatures? Detection only? Not temperature? In other words you want to know there is a hot object on a cold plate not how hot the object is?

 

[MIMSAR]

Thanks,

Object of interest is about 50mm diameter and should be about 19 degrees. The surface is technically unlimited and has a temperature of about 17 degrees.

Yes, I'm only interested in detection (e.g. scanning the sensor over a large area and it should bleep (arbitrarily) on detection).

Comments welcomed!

 

[Reloadron]

This is a very good read on IR Pyrometers. I suggest you give the link a good read, especially the section that talks about: "What is emissivity, and how is it related to infrared temperature measurements"? Emissivity can be a key element in the game and how well an IR temperature sensor can read from an object. I have had very good and accurate results with some materials and lousy with others.

You are looking at a very small temperature change between your table surface and the object which can be a problem, however, if you scroll down this page you will see quite a few flavors of IR pyrometers, including those with an analog output. Possibly one with a large enough analog out per degree change could drive a comparator or a design along those lines. Just something to consider. The sides of the pages linked to have a wealth of information with other links. Including more information on emissivity.

Calibration of these sensors for accuracy as to temperature is generally done using a "black body" and you will see those in the links.

Ron

 

[MIMSAR]

Thanks for that... will have a read.