Electronics > Metrology

Proper way of connecting thin film PT1000 sensors

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miro123:
Thanks for all answers


--- Quote from: branadic on December 03, 2022, 10:52:15 am ---First question to answer is, at what temperatures you want to operate the temperature sensor.
-branadic-

--- End quote ---
I use those sensor mostly under T=200C - T&M ovens. The temperature in most application even does not go beyond 85C.

I have many of then some have Au or Ag but some are Ni  - Most of the time I use easy soldered components - unfortunately my internal stock runs emty and I have to switch to dificult to solder parts.




--- Quote from: doktor pyta on December 03, 2022, 02:53:52 pm ---I use spot welding using graphite electrodes pulled out from zinc carbon batteries.
The graphite is used because it does not stick to both welded wires.

Popular spot welders used for LiPo battery packets welding are not sufficient to my experience.

Below some photos from the deep past.
Regarding reliability: approximately 30 sensors work without failures for 6 years operating at 200'C.
Kynar insulation of the wires puts a limit here.

--- End quote ---
Thanks, I've started building the similar spot welder setup.

So I will try to find use of those nickel wired PT100/1000 sensors.

By my next purchase I will careful select Au/Ag plated wires.

- they are easier to solder

- the thermocouple effect is less dominant compared to Ni -> Cu.





Another aspect is the long term stability of those sensors. I was not aware about it. I find  link below interesting

https://www.eevblog.com/forum/metrology/long-term-stability-of-temperature-sensors/

Background information  - My reference resistor project

----------------------------------------------------------------------------

for my reference resistor project I want to have temperature sensor.

Four Vishay resistors in two serial two parallel are submerged in silone oil bath.

Mechanical part is almost ready.

All ordered component arrived

I tough that temperature sesnor in silicone oil bath was a easy task. But it seems that PT sensors with good defined long term stability are rare.

Happily my requirements are not tight - something like T=0.1K @15..20years. is still ok. Inert silicone oil environment should help too.

I start leaning toward NTC for this application

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwjI-NiY-OD7AhXQsKQKHacnCQsQFnoECAYQAQ&url=https%3A%2F%2Fwww.eevblog.com%2Fforum%2Fmetrology%2Flong-term-stability-of-temperature-sensors%2F%3Faction%3Ddlattach%3Battach%3D412153&usg=AOvVaw09Khd8-kgf81hOig-AK4hG


Summary : The SMD-type sensor from Muratamanufacturing (NCP15XH103D03RC) intriguingly showed the least drift performance of 0.492 mK/year pp.




Greetings,

Miro

maat:

--- Quote from: miro123 on December 04, 2022, 08:57:16 pm ---Summary : The SMD-type sensor from Muratamanufacturing (NCP15XH103D03RC) intriguingly showed the least drift performance of 0.492 mK/year pp.

--- End quote ---

If you need to go nuttier, other alternatives might be:
Yellow Springs Instruments 44016, they are claimed to be stable to 100 µK in 8 months (https://aip.scitation.org/doi/10.1063/1.1686523).
This part of YSI was sold to Measurement Specialties Inc. in 2006, which was then sold to TE connectivity in 2014, sad story, but TE still sells them: https://www.mouser.de/ProductDetail/Measurement-Specialties/11032565-00?qs=FP9LbDqJ9ln9%252B5t8q1j%2FzQ%3D%3D

Kleinstein:
If long term stability over a limited temperature range is the target the NTC type sensors are indeed a good alternative. It is not just the sensor itself. With the higher rate of resistance change the measurement side  / referece resistor gets less crictical and one can often get away with 2 wire connection.

A Ag/Au plating has very little effect on the thermal EMF. This applies to the good and the bad.  The bulk of the conductivity is still through the bulk of the wire and thus thermal EMF also from there. The temperature difference over the thin plating itself to the base metal is very small and this not much thermal EMF effect there either.

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