Calibrating RTD Sensors with 3 Instruments: Rajesh's Guide

[Rajesh B]

HI..

This is my first post here.

I want calibrate RTD sensors so I am planning to buy Temperature calibrators includes three instruments with individual reference senors for three different set points(-ve, and two positive points).

I am planning to calibrate RTD sensor by these three instruments, so for -ve setpoint I will use one instrument out of three with dedicated master reference sensor for this and for second setpoint(+ve) I will use another instrument and a separate reference master senors for this and in the same way for third set point I will use third instrument and a separate reference sensor

Here I am having doubt that whether international temperature standards supports these type of calibration of a same sensor with different reference sensors for different set points.

Thank you.

Rajesh

 

[Jeff Rosenbury]

Good luck.

Am I missing a questions here?

 

[Baluncore]

Welcome to PF.

Maybe you should consider three insulated baths at different regulated temperatures. Each would have a stirrer to keep the water moving and a RTD sensor in a bridge circuit. The bridge output voltage null would control the heating or cooling. The difference voltage could be displayed to confirm a stable temperature. The cold bath might use brine or glycol with a peltier cooler, the others plain water with resistive heating elements.

You can check the bath temperatures with a calibrated master sensor.

Then calibrate your RTD sensors in those three baths.

 

[dlgoff]

When performing calibrations for a pharmaceutical company (& they have high "standards", pun intended), I used a http://www.amphenol-sensors.com/en/products/validation-and-environmental-monitoring/reference-standards/3133-kaye-irtd-400-intelligent-rtd-secondary-standard as the standard and a http://www.amphenol-sensors.com/en/products/validation-and-environmental-monitoring/calibration-baths/3129-kaye-htr-ltr-series-uniform-dry-wells as the temperature source.

 

[Rajesh B]

Thank you Baluncore

But I am directly buying three instruments having dedicated individual master RTD sensors and when I give my required set point then the bath temperature will raise upto set point and stays there now I place my testing RTD into bath and take the readings with reference to master RTD senor next I will keep the same testing RTD in next bath, having different master RTD sensor, for other set point. so is it acceptable as per international temperature standards that calibration of same testing RTD sensor with different Master RTD sensors for different set points

Thank you

Rajesh

 

[Rajesh B]

When performing calibrations for a pharmaceutical company (& they have high "standards", pun intended), I used a http://www.amphenol-sensors.com/en/products/validation-and-environmental-monitoring/reference-standards/3133-kaye-irtd-400-intelligent-rtd-secondary-standard as the standard and a http://www.amphenol-sensors.com/en/products/validation-and-environmental-monitoring/calibration-baths/3129-kaye-htr-ltr-series-uniform-dry-wells as the temperature source.Thank you dlgoff

Thank you for your suggestion on Standard RTD sensor and Temperature source instrument. so if I buy three Kaye LTR dry wells and three Kaye IRTD sensors since i want calibrate more sensors with in less time. so now I want to calibrate my RTD sensor in three different points so what i do is i will keep ready the three instruments at different set temperatures and individual standard sensor in each instrument.

so now i will place my RTD 1st instrument and take the standard sensor1 reading and my RTD reading and now I will transform My RTD into second instrumet which is having Standard sensor 2 and i will take the readings and i wll transform my RTD in third instrument which is having Standard sensor 3 and i will tak readings.

so is it acceptable calibration of same RTD sensor with different standard RTD sensors for different set points

Thank you

Rajesh

 

[dlgoff]

When performing calibrations for a pharmaceutical company (& they have high "standards", pun intended), I used a http://www.amphenol-sensors.com/en/products/validation-and-environmental-monitoring/reference-standards/3133-kaye-irtd-400-intelligent-rtd-secondary-standard as the standard and a http://www.amphenol-sensors.com/en/products/validation-and-environmental-monitoring/calibration-baths/3129-kaye-htr-ltr-series-uniform-dry-wells as the temperature source.Thank you dlgoff

Thank you for your suggestion on Standard RTD sensor and Temperature source instrument. so if I buy three Kaye LTR dry wells and three Kaye IRTD sensors since i want calibrate more sensors with in less time. so now I want to calibrate my RTD sensor in three different points so what i do is i will keep ready the three instruments at different set temperatures and individual standard sensor in each instrument.

so now i will place my RTD 1st instrument and take the standard sensor1 reading and my RTD reading and now I will transform My RTD into second instrumet which is having Standard sensor 2 and i will take the readings and i wll transform my RTD in third instrument which is having Standard sensor 3 and i will tak readings.

so is it acceptable calibration of same RTD sensor with different standard RTD sensors for different set points

Thank you

Rajesh

You will be wasting your money by having a standard RTD and Temperature source for each of the three temperature setting (calibration points), as they are quite expensive. One standard RTD in one Temperature source is all you need to do multiple sensor calibrations since the Temperature source can accommodate several sensors at a time. Take the reading from all sensors at the first set-point (what the standard RTD is indicating); I would start with the lowest setting, then ramp up your temperature source to the next set-point (again what the standard RTD is indicating) and take those sensor reading. Lastly, ramp up you temperature source to the final set-point using the standard RTD's reading as before and take those sensor reading. Note that:

Both the HTR and LTR series models feature fast heat up and cool down, a capacity to hold from 18 to 24 thermocouples ...

You just need to let the temperature of the source equilibrate (stabilize) before taking any readings. You shouldn't be trying to rush these kinds of calibrations anyway.