nght ty a "grain of wheat " light bulb, the resistance goes down when they are exposed to heat, like the old "magic candle" circuit that sensed heat from a match and lighted the bulb.

 

@Milani, maybe this will help you in your search for a sensor, then Google "optical pyrometer" for more ideas if this fits your criteria. http://www.temperatures.com/opyro.html

The last picture kind of looks like a 'flue temperature probe' sensor, they were once used in oil furnace burner control circuits. Don't think they still are used in modern furnace controls though.

 

@Milani, maybe this will help you in your search for a sensor, then Google "optical pyrometer" for more ideas if this fits your criteria. http://www.temperatures.com/opyro.html

The last picture kind of looks like a 'flue temperature probe' sensor, they were once used in oil furnace burner control circuits. Don't think they still are used in modern furnace controls though.

hi
this is not a tempreture sensor ...........and not a light sensor ... this sense flame or hot metal ....... i think that it sense infrared vawe frome heated device ..........

Moderators note: large bold fonts are like shouting.

 

Hello,

You might want to read this page:
http://www.electronicshub.org/simple-fire-alarm-circuit/

There is stated:

The conduction of germanium diode will start at 70 degrees. So we may use germanium diode as a heat sensor.

Bertus

 

i have a other sensor ..... that is similr to sensor of post 1

this is not a tempreture sensor ...........and not a light sensor ... this sense flame or hot metal ....... i think that it sense infrared vawe frome heated device
..........
i do very experiment on this sensor .....this sensor no act to tempreture or hot objects...
this sensor act when it sense hotmetal mill with red vawe ........
it also act when it sense flame or fire directly...........since it have red or orange vawe...........
i am sure that this sensor sense infrared vawe emitting from hi tempreture device........for example infrared vawe emiting from hot metal from 1300 degree c.......

please help for finding modern sesor ............with description of top .....

thanks...

bahram. milani

Moderator note: large and bold fonts are like shouting

 

hi
this is not a tempreture sensor ...........and not a light sensor ... this sense flame or hot metal ....... i think that it sense infrared vawe frome heated device ..........

Moderators note: large bold fonts are like shouting.

These can sense what your asking, not just temperature. They work by reading the incandescence of an object. This also let them read temperature, but temperature is what they are mainly used for. In the oil furnace control they were to shut it down before the flue got hot enough to burn any vapors in the chimney, causing an explosion. But it's your call to use the information.

 

hi
plaese introduce me a modern ainfrared sensor with wavelengh 1um to 3 um....