Continous temperature measurement

[Uinseann]

Hi
I need to measure the temperature between 2 ceramic plates (30mm wide, 500mm long) which are in contact. A heat source will pass from one end of the plates to the other and the power to the heat source will be modulated via the temperature measurement device. A pyrometer could be used if we were to use glass as our upper plate. However since the ceramic is not transparent the pyrometer is not an option. The max temperature will be approx 450C.

So what I’m looking for is a thin continuous temperature sensor. Any suggestions greatly appreciated.


Thanks

 

[danw2]

>temperature between 2 ceramic plates (30mm wide, 500mm long) which are in contact.

'between' means? The temperature differential between the surface of one plate and the surface of the other?

or the temperature of a gap between the plates?

or something else?

>A heat source will pass from one end of the plates to the other.
>the power to the heat source will be modulated via the temperature measurement device.

Controllers modulate. Measuring devices measure. Measuring devices can supply an input signal to a controller, which can modulate. Unless you have some other piece of equipment that is doing something that is inferred by 'modulating', and that would be?

>A pyrometer could be used if we were to use glass as our upper plate.

What does this theoretical pyrometer see? What does it focus on? Are you inferring that you've used a pyrometer to 'see through' glass to another object?

>However since the ceramic is not transparent the pyrometer is not an option.

because . . . .

>The max temperature will be approx 450C.

So what I'm looking for is a thin continuous temperature sensor. Any suggestions greatly appreciated.

 

[Uinseann]

Apologies for being a little unclear. I want to measure the temperature of the gap between the plates. Actually there is a third layer of material positioned between the 2 plates and it is the temperature of this material that I need to monitor.

I understand that we need a controller to 'modulate'. We connect a PID controller to the measuring device for this.

Yes, the pyrometer that we have used is designed to see though glass and could therefore be focused on the third layer of material sandwiched between the 2 plates. However, the ceramic is not IR transparent and hence the pyrometer can not see though it.

Hope that makes a bit more sense!

Thanks

 

[KiwiMace]

I don't think you need what you think you need. Why not insert several thermocouples and average them, or control to max reading or whatever suits your objective. Even if you have an infinite number of meaasurement points, you still have to control to a single finite setpoint. What will determine the evenness of temperature is how evenly you apply the heat (or remove it). You will not measure good control into your process.

 

[jmw]

Or thin film resistance element embedded in the intervening layer?

JMW

http://www.ViscoAnalyser.com

 

[knapee]

Available commercial/standard ranges of bimetallic thermometers are from -80°F to +1000°F.
Bimetallic thermometers are not recommended for continued use above 800°F. The thermal
stability of the bimetallic thermometer is an inherent characteristic of the metals used and
continued operation cannot be assured above 880°F.

 

[glowing]

if you want to get fancy...thermal imaging. I used it on a staged coker in a lab that required tight control. It exceeded my expectations.