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laxman · 03-28-2006, 07:35 PM

Your problem is that RTDs have way to low of a slope. Meaning a .01% error in resistence is a around a 3c error. This does not fit calibration standards by a long shot. Do any of you multimeters have a have a ohm range of 2000? If they do then you can cross calibrate your RTD and thermometer by using a NTC thermistor. I cant remeber the series but one has a resistence of around 1500 Ohms at 30c. Using the known temperature/resistence relationship of the thermistor you can pretty accuratly measure the temperature in a controlled water bath. Then you can use that temperature to calibrate your thermometers.

Although I think that it might be easier if you just had someone else calibrate them. I could do it, I have a temperature calibrator and two thermometers that are accurate within .005c (NIST traceable too).

03-28-2006, 07:35 PM	#2
laxman Cooling Neophyte Join Date: Oct 2005 Location: evanston Posts: 41	Re: Simulating an RTD Your problem is that RTDs have way to low of a slope. Meaning a .01% error in resistence is a around a 3c error. This does not fit calibration standards by a long shot. Do any of you multimeters have a have a ohm range of 2000? If they do then you can cross calibrate your RTD and thermometer by using a NTC thermistor. I cant remeber the series but one has a resistence of around 1500 Ohms at 30c. Using the known temperature/resistence relationship of the thermistor you can pretty accuratly measure the temperature in a controlled water bath. Then you can use that temperature to calibrate your thermometers. Although I think that it might be easier if you just had someone else calibrate them. I could do it, I have a temperature calibrator and two thermometers that are accurate within .005c (NIST traceable too).