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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MAX31865 power supply and filtering
I am designing a RTD circuit for PT1000 using the MAX31865 IC, and by reading the datasheet, I am a bit confused/in doubt.
There is no info in the datasheet about using separate analog/digital power ...
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VREF for MAX31865 design
I am designing a circuit with the MAX31865 RTD IC, and I am reading the pin description of the DVDD and VDD pins. The datasheet states that these two pins should be connected to a 3.3V power supply.
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How to connect heaters and RTD sensors from an EMC perspective
I have a PCB that drives an external system with simple resistance heaters and Resistance Temperature Detector (RTD) sensors for temperature readings placed close to them. The PCB includes a typical ...
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PT1000 drifts more than 100°C
I'm using a PT1000 and MAX31865 to measure the temperature inside a machine.
Electronics (MAX31865 and MCU) are inside an isolated box. The PT1000 is outside and connected in two wire configuration (...
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STM32H723 ADC3 Hardware Auto-Calibration Behaving Unexpectedly
I am trying to read from the ADC3 module of an STM32H723. ADC1 and ADC2 have been previously set up, although I was using a manually added constant offset rather than the automatic calibration in ...
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Using solder to extend RTD cable?
I have a 3 wire RTD sensor (Pt100). The leads coming off of it are not long enough to reach our temperature controller. I bought some RTD extension cable (3 wire) from the same company.
Is it okay to ...
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How do people ground cable shield on thermocouple cable?
I am building an electronic controller that measures the temperature on a metal chamber. Type K thermocouple sensors are placed on the metal chamber, and type k thermocouple extension cable connects ...
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Dual Input Signal Conditioners and 4-wire RTDs
I am new to electronics/sensors and am working on integrating two RTDs into a DAQ for a school project. I want to use an Omega TXDIN70 signal condition to interface between the DAQ and RTDs, as it has ...
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Is there any standard to define the accuracy of RTD transmitters
I wonder if there is any standard which defines how is the accuracy of RTD, pT100 in particular, tranmistter defined and with which confidence level.
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Best method to sense low temperatures while using low current
I need to measure temperatures of -80C, and the circuit needs to be battery-powered. So I thought an RTD probe with the MAX31865 RTD-to-Digital Converter would work well. I am using an nRF52840 for a ...
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Wheatstone Bridge with Instrumentation Amplifier
I have set up this circuit:
I measure an output of 0.61 V from the instrumentation amplifier. The gain of the amplifier is set to 21. The formula for the output is given by:
Uout=(1+2R1/Rg)×(R3/R2)×(...
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MAX31865 RTD IC: What is CI's capacitor purpose?
What is the Purpose of CI capacitor? The datasheet does not mention anything for it except its recommended value.
My guess is that it is used to suppress RF noise on the PT100/PT1000 cable. But It ...
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Please help me to get data from ADS1247IPWR
please help me. I tried many times and many designs to reslow my problem. My ADC1247IPWR is measuring always the same value. Perhaps looks like I configured it wrong. My valve is changing if I use ...
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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 ...
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Can I read the voltage (MCU ADC) with an isolated power source by opamp inputs?
I made a conceptual design to read an industrial 2- or 3-wire temperature sensor with a single 3-connection terminal.
I used an opamp in differential mode to read two terminal connections which are ...
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Read 2-wire or 3-wire temperature sensor by unique connection to Arduino
I have 2 types of temperature sensors, 2-wire, and 3-wire RTD
I look on the internet and I've seen many schematics use the simple voltage divider for 2 wire sensors and the Wheatstone bridge for 3 ...
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RTD - convert measured voltage to temperature
I have a 3-wire RTD connected to a Wheatstone bridge and then to a INA. The Vout from the INA is then connected to a ADC. How can I convert the measured voltage from the ADC to the respective ...
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3 wire RTD with current source and INA
How would I connect a 3 wire RTD using current source and a instrumental amplifier for the output?
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3 wire RTD configuration Wheatstone bridge Vs. Constant Current Source
I am trying to design a 3 wire RTD circuit. I've been looking into either a Wheatstone bridge or a constant current source with ratiometric measurements. I would like to know which is the better ...
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LTC2498: different voltage on input and muxout
I am measuring RTD (4-wire connection) with an AD LTC2498 ADC. The ADC responds to commands via SPI, so does return data. The problem is that the voltage at Vn/Vp does not match the one at muxoutpn/...
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PT100, MAX31865 Calculation and Circuit Theory Problem
I have designed a 2-wire RTD circuit using MAX31865. The circuit based on application circuit. But I have a serious problem about the REF resistor and excitation current. In the datasheet, Maxim ...
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Does an RTD simulator require calibration?
Does an RTD simulator need calibration or not? Basically, I can measure that the value of RTD with a calibrated multimeter and I can show the difference between multimeter and RTD simulator. So, can ...
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Why is RTD immune to electro-magnetic fields? [closed]
Thermocouples may have added voltage & induction heating induced in a magnetic field, throwing off the measurements.
A Resistance Temperature Detector (RTD) is said to be a good alternative. Why ...
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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 ...
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RTD Simulator vs Resistors
I want to use an RTD simulator for my project to simulate the PT100 0r PT1000. But I ant to learn that is it really necessary to use a simulator? Of course I can use some different kind of resistors ...
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MAX31865AAP+ PT100 Excitation Current Problem
I have a PT100 and I'm using MAX31865AAP+ for RTD-to-Digital Converter. But I have a problem and I don't understand why this is. I use 400R REF resistor for PT100 and the reference resistor current is ...
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MAX31865 and MAX31855 Completely not Working
I am beginner in Electronics.
While working with MAX31865 and MAX31855 Modules it was working perfectly, but after designing custom PCB based on modules its not working.
RTD shows -242C and 982C ...
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RTD lead-wire composition: choosing between silver or gold-plated nickel wires
I am selecting a platinum thin-film RTD for a sensing application. I have settled upon TE Connectivity's PTF Family. Within this family, there are two different options for lead-wire composition:
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RTDs: Resistive Divider or Wheatstone bridge
I've inherited a PCB design in which the circuit for reading a 1k 2-wire RTD sensor is a simple resistive divider. The R_rtd is the pulldown part of the divider. The voltage of the divider is read ...
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RTD non-ratiometric ADC measurement
I am thinking of replacing standard ratiometric RTD measurement (of temperature) with two sequential measurements.
The reason is I have to use an ADC already on the PCB and cannot replace its ...
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LTspice: Can I simulate current generated heat?
I'm simulating a simple circuit with a resistance temperature detector. I want to know if it is possible to simulate the small change in the resistance as the current flowing through the resistor ...
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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 (...
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3-wire RTD measurement circuit
I'm searching for some simple 3-wire RTD sensor to be measured using an ADC. I found some options, but I'm kinda confused with how does they works and which one is the best.
First, there is the ...
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RTD reads differently with different monitors
I have an RTD that I am reading with a Jenco 77A 4-20mA converter and a reliable 4-20mA supply/display. When I turn on a nearby AC electric motor, the indicated temperature jumps 50°C (which is ...
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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, ...
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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 ...
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pt100 RTD transmitters not working - two in a row - am I doing something wrong?
I just tried to use two different ones of these RTD transmitters with a pt100 probe (3 wire) with no success.
I am connecting the transmitter directly to a 4-20mA input on a PLC, as shown in the ...
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RTD with a +/- 0.01 oC from its normal set value (78.37oC)
I am doing an assignement and have been asked to find a TMS for a whiskey distillary and I cannot find a suitable RTD. The parameters are that it needs to have a T range between 0 and 120 degrees ...
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PT100 temperature sensor: meaning of "measuring current" specification
I'm measuring temperature using a PT100 temperature sensor on a Wheatstone bridge.
As I'm working on a battery powered application, I'm choosing the resistors in the bridge so that only a small ...
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Isolated RTD sensor
I need to read a Heatsink temperature with 5KV isolation.
how is it possible?
are there isolated temperature sensors ? or
shall I design a board for it to isolate the output signals?
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Purpose of capacitors connected to both inputs of Op-Amp
What is the purpose of the capacitors in the following circuit? Using Ohm's law :
V+ = I * RTD
V- = I * R3
and also :
Vout = G * (V+ - V-) =>
Vout = G*I(RTD - R3)
The circuit is used to measure ...
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Sharing a single ground wire across multiple RTDs
Consider the following, simplified schematic for a single, two-wire RTD sensor:
simulate this circuit – Schematic created using CircuitLab
The two wires from the RTD sensor plug into pins 1 ...
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How to use a power meter to measure irradiance?
I have got a Zes Zimmer LMG95 power meter and an RS-ID-5 Fraunhofer ISE WPVS reference cell.
The LMG95 has got simultaneous voltage and current measurement and can do custom calculations. The WPVS ...
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Working of INA826 instrumentation amplifier for Pt100 RTD
The schematic below contains an INA826 used to amplify the resistance of the Pt100 RTD across J1. Gain is set to 10 through the 5.49K ohm resistor.
Is this ciruit amplifying only the voltage across ...
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What is the correct configuration for 3-wire RTDs connected to an ADAM 6015 module?
I have connected four RTDs by wire (via a 12 pin cable). The common wires of all four RTDs go through only two of the wires in the cable. After soldering those wires together and connecting them to ...
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Why is there a negative value on the scada when the analog input wire is disconnected from a field instrument?
I'm an apprentice electrician at an fmcg company.
I've been seeing a trend recently, at the plant, where the scada actually reads a negative value instead of zero when a field device such as a ...
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What causes long-term RTD reading drifts?
I am working with a controller that was designed to read multiple types of inputs including 3 wire RTD signals.
In some cases, we have observed the controller suddenly spike up +15 degrees and ...
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How are and what are the sources coupled to a 3-wire RTD leads? [duplicate]
I can understand two or four wire connection for RTDs. But I don't get where they apply voltage or current and how they measure the resistor values for 3-wire connection:
Here is a page about these ...
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ITS-90 Tempature coefficents for a standard PT100 385 RTD
I'm currently using the ITS-90 formula to convert a resistance of an RTD to a temperature. I got the coefficients from the manufacturers calibration sheet. The problem is I have another probe that I ...
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PT100 - 39250 Cubic fit formula
I'm currently using a cubic fit formula I found online to derive the temperature of a PT100/385 RTD using resistance. The formula is -247.29 + 2.3992*R + 0.00063962 *R^2 + 0.0000010241 *R^3 where R is ...
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