Control.com - Nerds in Control

Hi,

I truly hope I might get some direction here. I am no an EE. I only know the rudiments of thermistors. I need to replace a couple of them in a water cooling circuit. Two LED panels register F. from approx 60 to 200 degrees. I have a sample thermistor from a sending unit matched to the LED panel. I am trying to find replacements so that a pair of identical thermistors will feed the panels. One panel is for cool/out the other is for hot/in. I developed a graph based on temp rise using a multimeter and digital thermometer in my own workspace.

http://img381.imageshack.us/my.php?image=finalrtcurveforthermistja 3.jpg

And I sent the thermistor into a manufacturer who tested it and determined that it was approx 1006 ohm at 25C and 142ohm at 70C.

Everywhere I look, I am told that this cannot be replaced with an off the shelf part. The LED panels are only for visual confirmation of relative temps to monitor efficiency of the system. The data does not control process. I don't think I need high accuracy. A 'bead' type thermistor would be best suited to me for implementing a thermistor into this cooling circuit. All of the tables, curves, charts and graphs accompanying thermistors really make my head start spinning. Is this really such an insurmountable quest?

How close would I actually get (in the real world, without being too technical) with a part such as this:

http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=P 10537CT-ND

An SMD device would work ok for me.

Thank you so much for any advice at all. This device is turning into a major stumbling block in this project.

Amanda

Hi,

Is it so that your thermistor is Pt 1000? Pt 1000 has got 1000 ohms resistance when temperature is 0 degrees of Celsius. After all, is your sensor NTC (negative temperature cofficient) or PTC (positive)?

tn