Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [rtd]

Resistance Temperature Detector (RTD). An RTD sensing element usually consists of a metal filament, which is coiled on a mandrel or etched on a substrate. The RTD element is made from a pure material, typically platinum, nickel or copper. The material has a predictable change in resistance as the temperature changes; it is this predictable change that is used to determine temperature.

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Why does a Pt100 RTD fail after immersion in thermally conductive and electrically isolating paste?

I currently have a Class A Pt100 RTD connected via an Adafruit RTD amplifier to an Arduino using SPI. It has good thermal contact with the warm surface after immersion in a thermally conductive (and electrically isolating) paste. There is no…
Jeremy G
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Is it normal to have this much fluctuation in an RTD measurment in boiling liquid?

I'm using a MAX31865 RTD measurement IC, and a standard PT100 RTD to measure maple syrup temperature as it's boiling (219 degF). At ambient, the temperature measurement is reasonably stable. But, when boiling, I get a substantial amount of drift. …
gtetil
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Can't get a precise reading with PT100 temperature sensor

I am trying to get more precise temperature value from PT100 ( 2 wire ) sensor with Arduino. Here's how my circuit looks like : When the sensor is about 20 °C I get a value on A5 pin that is 432 and when the sensor is about 30 °C I get a value on…
Muhamed Krlić
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RC filter on ADC voltage reference pins: overkill or necessary?

I've been scouring the web for circuits suitable for reading RTDs using ADCs. In one document from TI it is suggested that the following filter be placed on the inputs of the voltage reference pins (REFP0 and REFN0) which matches the filter on the…
hadez
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Nickel 500 and 200 ohms at 0 Celsius

I'm trying to find resistance table for Ni 500 and Ni 200. I found tables for Ni 1000, Ni 100, NiFe 604 and NiFe 507.7. But I wasn't able to find resistance to temperature table for Ni 500 and Ni 200. Could you please give me these tables? Or is it…
user1529034
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4 wire RTD (PT100) in a wheatStone bridge

I want to connect a 4 wire RTD PT100 in a wheatStone Bridge. I tried searching on internet but only up to 3 wire configurations in bridge are available or circuits using other ADS IC's are available. But I want to do it in a Bridge…
Priyanka
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Why does a resistor have this value in a circuit with an operational amplifier?

I'm analyzing this circuit to condition a PT100. I clearly understand what the circuit does, but the current flowing through R7 is very small and negligible. So in theory it could be any value (generally from 1k to 100k), but I don't understand why…
Fabián Romo
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How do Resistance temperature detectors (RTD) work?

What is the difference between RTD and Thermocouples ?
Pritam
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Accurate yet relatively simple way to use RTD probes

I would like to build a reference thermometer for checking and maybe calibrating other sensors and I was planning to use 1/10 DIN RTD probe in order to do that. You can get such probes for ~$100 and the error is ≤±0.07C in -50°C - 50°C range, which…
Piotr Sarnacki
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Are 4-wire resistance temperature detectors sensitive to ambient temperature?

We're using a TI LMP90080 as an ADC to read a 4-wire resistance thermal detector (RTD) in the following circuit: The problem we are having is that when the ambient temperature changes, especially near R88, a 25ppm/°C 0.10% 1k resistor, the reading…
Phyllostachys
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Why does an RTD sensor circuit use a reference resistor that is 4x the RTD value?

I'm using an Adafruit MAX31865 board to measure the resistance of a PT1000 RTD. The board comes with a 4300-Ohm resistor. I'm trying to model the amount of noise (in degC/sqrt(Hz)) that I expect out of this circuit. But in order to do that, I'm…
Jonathan Wheeler
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How do I measure a PT100/1000 with a Arduino over I2C?

How do I measure one or more PT100/1000 (PTC Resistor) with a Arduino/ATmega328 over I2C? Are there any ready microchips? Do I need to construct my own circuit? If so, are there any ready schematics?
chriszero
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RTD's resistance to temperature

What is the formula for finding temprature from resistance? I want to use it with PT 100 / 500 / 1000 .
user1529034
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Single current source with parallel loads for many RTD sensors

I'm trying to build a circuit that contains multiple 3-wire RTD PT100 sensors (12 of them). I have a microcontroller with plenty of ADC pins so I could potentially measure the RTD and the wire resistance on the ADC without an extra opamp to cancel…
Bob Baddeley
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PT100 at temperatures beyond the rated range

What happens if a PT100 such as the P1K0.232.6W.B.010 is exposed to higher temperatures, e.g. at 700°C instead of its rated upper limit of 600°C? Does something destructive happen that damages the PT100 fast or over time or is just accuracy…
Hyp
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