PT100 converter

[AndyB]

Hi is anybody aware of a cheap  module that converts a PT100 temperature sensor to 0-10v output to input into a logic controller. The options i have looked at are around £90!

Thanks

Andy

[hiccup]

Hi

Depends on the required accuracy, and if you need the 0-10V to be linear with respect to temperature or whether the thing reading the 0-10V can/needs to do the linearisation.

It also depends on the temperature range.

For an approximate result you can just feed the sensor (Rsensor) from a stable supply (Vsupply) via a decent resistor (Rref) and with ohms law and a bit of math you can calculate the Sensor resistance and hence the temperature.

Rsensor = Vsensor * Rref / (Vsupply - Vsensor)

Pt100 sensors have an alpha of around 0.385Ohms per degree C and are 100Ohms at 0C. You might need an opamp to shift / scale the output to the range you need.

However if you need a calibrated converter, £90 is cheap!


Hope this helps

Hic!

[Panda]

My reply is a bit late I know but if you're still looking I have used this company before for PT1000 to 4-20mA converters. They seemed able to source a lot of different types so could be worth a try:

    
Measurement & Control Technology Ltd
16 Draycott Close
Penn
Wolverhampton
WV4 4SD

Tel: 01902 342405
Fax: 01902 461920
Email: sales@mct-ltd.co.uk

[AndyB]

Thanks for the info, I got one from Conrad Electronics but thanks for putting me on to these guy/s

Andy