10 ohm Platinum RTD
10 ohm Platinum RTD
(OP)
We're working on a small generator made in Spain and trying to sort out the stator and bearing RTDs.
We have a spare bearing RTD - it is marked as "1 Pt10 (3h)". It measures about 11.2 ohms at room temperature. If we treat it as a 10 ohm Cu RTD, the temperature readings are not accurate.
I understand that 10 ohm Platinum RTD are used in Europe, but I'm having problems finding much information. We like to find a transmitter or transducer that can accept this input and provide a linear output - 4-20 mA ideally.
Anyone have any experience with 10 ohm Pt RTDs?
Thanks,
Dave
We have a spare bearing RTD - it is marked as "1 Pt10 (3h)". It measures about 11.2 ohms at room temperature. If we treat it as a 10 ohm Cu RTD, the temperature readings are not accurate.
I understand that 10 ohm Platinum RTD are used in Europe, but I'm having problems finding much information. We like to find a transmitter or transducer that can accept this input and provide a linear output - 4-20 mA ideally.
Anyone have any experience with 10 ohm Pt RTDs?
Thanks,
Dave





RE: 10 ohm Platinum RTD
RE: 10 ohm Platinum RTD
Ooops I just found a reference to a 10 Ohm Birdcage model in Omega catalog
You should use the 3 wire method otherwise the interconnecting cable will give you errors.
If by any remote chance it is Pt you can look at the tables for 100 Ohm and divide by 10
e.g. 10 @ °C, 13.85 @ 100°C
Regards
Roy
RE: 10 ohm Platinum RTD
Cu 9.035 @ 0, 12.897 @ 100 C or Delta 3.8625 Ohms
Pt 10 @ 0, 13.85 @ 100 C or Delta 3.85 Ohms
I don't think you will have any difficulty offsetting the zero to match Pt. Worst case you could add a little resistance.
So purchase a 10 Ohm Copper transducer, it may not be perfect but close enough for a motor
RE: 10 ohm Platinum RTD
I've used this in the past http://w
RE: 10 ohm Platinum RTD
For the short term, we can set the trip setpoints to be correct at the trip temperature. I'm just looking for a longer-term off-the-shelf solution. We could replace the bearing RTDs without too much trouble, but the stator winding RTDs would be hard to replace.
Dave
RE: 10 ohm Platinum RTD
I did find the ABB model that can accept the Pt10 inputs - so that is definitely a possible solution.
This generator has been in service for about 15 years and apparently no one noticed (or cared) that the RTDs were not accurate.
RE: 10 ohm Platinum RTD
Get a temp controller or an RTD calibrator that takes in a 10ohm CU RTD. Hook it to that spare PT RTD you have. Then toss it into a temperature space at your critical temperature point and see what reading you get. That would be the temperature you'd actually want to set your safety points at on your generator.
Keith Cress
kcress - http://www.flaminsystems.com
RE: 10 ohm Platinum RTD
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I think they are part of Omega
I have used indicators from Precision Digital, they have a multiplexer that can be used for RTDs
Use a Decade box for calibration, it's much quicker than heating/cooling a spare RTD
Roy