Questions tagged [thermocouple]
A thermocouple is formed by a contact of two (2) dissimilar conductors. The voltage across thermocouple is governed by Seebeck effect. Thermocouples are widely used as temperature sensors.
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How can I connect a 3 wire RTD to a 2 wire system
I received a thermocouple replacement part from a machinery company. It has 3 wires (white, black, green/yellow), but the thermocouple it is replacing only has 2 wires (white, red). Can I use the ...
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Setting the parameters of PID for 10 °C set point
I have a PID controller (REX C100), connected to a TEC1-12706 (Thermal Electric Cooling) and a thermocouple K-type. I want to set 10 °C on my PID.
The problem is that the actual temperature in PID is ...
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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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Output voltage thermocouple amplifier decrease when temperature increase
To detect surface temperature of heating foil, I decided to use thermocouple of type K. To amplify the small signal I choose the thermocouple amplifier with cold junction compensation integrated, ...
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Temperature sensor on a long wire (100ft) [closed]
I'd like to monitor the temperature of a variety of locations around my house but I don't want to rely on wireless technology. Are there temperature sensors that can be connected over long distances (...
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Knowing the transfer function of a system and the output, how can I get the input?
I have a system composed by k-thermocouple + metal handpiece, the thermocouple is drowned into the handpiece. If I manage to estimate a transfer function of the system so-made, for example trough ...
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Positive or negative Seebeck Coefficient?
Say I have a metal wire for a thermocouple, the cold end is 20C and the hot end is 500C. If I measured at the hot end of the wire with respect to its cold end and got a voltage of -3.6mV, would the ...
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I need to make a makeshift thermocouple given limited resources in the third world
I'm living in a part of the world where scrap electronics are hard to come by. Recycling these are big money in the impoverished SEA region I'm living in.
I have a Fluke 289 with a type K thermocouple ...
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How to correctly ground/isolate a grounded enclosure type thermocouple?
My K-type thermocouple (grounded enclosure type) connected to MAX31855 adapter connected to Arduino Mega gives me faults every few readings. It's really, really bad. I've tried swapping thermocouples, ...
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Should op amp reference terminal be connected to ground?
I would like to amplify the voltage from my thermocouple and had a couple of INA122s on hand. This is from the datasheet.
Should pin 5 be connected to GND? (pin 4)
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How do I make sense of the solution to this circuit analysis problem?
I am studying MIT's 6.01 on OCW and have been struggling with a sample final exam problem that involves circuit analysis with op amps. I'm hoping to get some guidance on how to approach the problem or ...
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Can I solder this cartridge heater to this thermocouple?
I'm trying to make a vaporizer pipe as a hobby project. The idea is that when you inhale from it, air passes by a cartridge heater and then goes through some "herbs". A thermocouple is used ...
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How to power a peltier element with something portable?
Actually the question is bigger. I will start from the beginning.
I want to make a surface, which I can carry in a bag with me, and when I turn it on I want a given part of the surface to become very ...
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Can an op-amp reduce its own gain after a failure?
I have a pellet stove that after few minutes from startup turns off. I discovered that the cause is the smoke temperature that is too low (~ 30 °C, read on the remote) even when it's burning. Of ...
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MCP9601 constantly indicating open thermocouple
While trying to get temperature values from my thermocouple amplifier, I am able to read the cold junction temperature, yet the hot junction temperature isn't even measured by the converter. Reading ...
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Please fix my broken understanding of this simple thermocouple circuit
Here's my qualm:
As per the diagram, I can't understand how the trim probe (resistor) affects the meter reading for this thermocouple circuit.
If I understand the diagram correctly, everything is ...
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Thermocouple measurement on PCB trace
Good day
I have not used thermocouple before. I only know the basic principle.
From what I understand, the voltage produced is due to the dissimilar metals with their joined ends being applied with ...
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Thermocouple parallel reading
I need to read 5 thermocouple sensors from a plastic injection machine. I want to use a MAX6675 because it has a cold junction compensation feature.
I can achieve parallel readings with 2°C offset in ...
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Thermocouple readings affected by PE
I designed a controller for an electric pizza oven. The PCB has an MP-LDE03-20B0 power supply module on it. Everything works great except for measuring the temperature in the oven. I use thermocouples ...
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TECs: parallel or series? [closed]
My project is regarding the cooling effect of TECs. I am from a mechanical background.
My question is: what happens when TECs are connected in series or in parallel? If one configuration is better ...
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IR and thermocouple measurement difference on large and high emissive objects
First of all, the question is similar to this one.
I am working on a high-power, high-density power supply where the size and heat dissipation are quite limited. In the final product, the PCB will be ...
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K-type thermocouple alumel/chromel soldering
I am using a K-type thermocouple for my project. I want to to use a connector which has alumel and chromel pins, but there is a problem there. Is it possible to solder alumel/chromel pins to a PCB?
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Sampling bottleneck due to sensor conversion time? MAX6675/MAX31855
The datasheets for the MAX6675 and MAX31855 say that their "temperature conversion times" are 220 ms and 100 ms respectively.
I am using an arduino to get the data from a K-type ...
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AD620 input voltage range identification
I wish to buy this AD620 amplifier module for amplifying my strain gauge voltage. I also wish to use it with my thermocouple. Basically, I want to accurately read DC voltage values from around 0.1 mV ...
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How can I read a thermocouple situation with an ESP32
The thermocouple has two pins (a ground, a 0 to -0.0004 when activate the bobbin to run the gas.) I want know how can I detect whether the gas is open or not without adding a sensor to the system. ...
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Picking TVS and ferrite beads for MCP9600 thermocouple converter
I'm about to use the MCP9600 thermocouple voltage to I2C converter for the first time. Because I need my output to be as precise as possible, I decided to apply the recommended circuit shown in figure ...
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Thermocouple short-circuit detection
I'm trying to figure out how to detect a shorted K-type thermocouple (between the wires, not a wire to GND or Vcc.) I would define a short as thermocouple resistance < 0.1 ohm as opposed to 1 ohm ...
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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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Attach thermocouple to a PFC inductor
The inductor I am talking about is simply a toroid. I am attaching a thermocouple junction to this component with help from thermal paste and aluminum tape.
Anything I should be careful about in this ...
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Can a K-type thermocouple measure both air and surface temperatures? [closed]
I want to use a K-type thermocouple to measure exhaust gas temperature and surrounding structure temperatures for my micro turbo jet engine.
I read in the comments of How to use MAX6675 thermocouple k ...
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Thermocouple circuit not outputting expected values
My application requires 11 thermocouples to be sampled and logged. Below is the circuit diagram, containing a differential and common mode filter, non-inverting amplifier (gain 111) and a second order ...
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Can I make a homemade Peltier module with constantan wire?
I'm trying to make my own Peltier module.
I ordered constantan wire, which I used as N-type semiconductor and iron wire as P-type.
I made this and powered it with 3V, but without response.
What am I ...
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Thermocouple actuated switch
So first of all, I'm a mechanical engineer and a terrible electrical engineer.
I'm trying to build a failsafe for a heating element. This heater has an integrated k-type thermocouple and is limited to ...
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Will reversing the polarity of a K thermocouple damage it?
I have a K thermocouple connected to a MAX31855KASA+T IC supplied by 3.3V. I mistakenly reversed the polarity and was taking reading from it for about 1hr. I am noticing the instrument is now ...
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Can a thermocouple be encased in a custom stainless steel tube?
I would like to read the temperature of oil in a metallic vessel. However I'd like to route the thermocouple so it stays out of the way. Is it OK to just insert the "naked" thermocouple &...
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Temperature circuit not functioning
I am attempting to help mentor some high school kids on circuits and obviously not doing a very good job. We are trying to get a prototype PCB working that uses a max31856mud datasheet and k ...
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Landing a Thermocouple on a surface with voltage present
I am connecting multiple K-type TCs (thermocouples) to an electric engine prototype. I have had a problem with the TCs having up to 150 volts on them when the engine is running. I don't know the ...
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Thermocouple IC MAX31856 circuit what is DRDY
I have a prototype board that seems to only output non-sensible values for K thermocouple readings, with no response to actual temperature changes. Prior to this a breakout board with this exact IC ...
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Furnace circuit ideas: constant temperature with thermocouple & heating element
I am wanting to make what we will just call a furnace that will always operate near 1800°F. I'm looking for circuit ideas or a direction in order to maintain the temperature of the furnace.
The ...
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Thermocouple bias with LTC2053
This LTC2053 application note shows a thermocouple bias using two 10 MΩ and two 1 MΩ resistors.
I understand the idea that the power supply is divided by two 10 MΩ resistors for good common mode ...
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Thermocouple K Type using a jack plug instead of the normal connector
I have a few thermocouple K Type using the classic two lead connector.
I would like to change that connector to a male jack type like this:
So I can connect it to the female connector that has ...
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Relay Module with Arduino Uno and K-Type Thermocouple
I am working on a project for school. The goal is to use thermocouples to measure temperatures. The measured temp will control whether or not the lightbulb is turned on. The components used will be an ...
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Thermocouple conductor direct current resistance
Does a thermocouple conductor have a direct current resistance requirement?
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Thermocouple wire diameter
I have four possible scenarios for making a type T thermocouple:
use a 24AWG copper wire and a 24AWG constantan wire
use a 20AWG copper wire and a 20 AWG constantan wire
use a 24AWG copper wire and a ...
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Output voltage at different output optical chopper frequencies
I have a circuit as shown in the figure and I am using it to extract output voltage of thermopile (to determine the time constant of thermopile ) at different output frequencies. The optical chopper ...
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Is it ok to solder thermocouple wire ends?
I am using T type thermocouple wire. I am using it in a situation where I don't want the sensor to fail hence I thought it is a good idea to solder the ends together instead of only twisting them to ...
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Using plain connectors on thermocouple / external cold junction compensation
We'd like to use plain automotive connectors to connect our thermocouples.
What we are looking for is the ruggedness and economy of such connectors.
Of course, that brings the problem of material ...
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Thermocouple wire extension
I want to use a thermocouple (K type) for a PID temperature controller in a heating system. The thermocouple should be pluggable to the system. I decided to use an industrial grade connector like ...
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Making Thermocouples With Only One Type of Wire
Can thermocouples be made with only one type of wire? I wonder if a thermocouple would work if I use two 10-cm copper wires given that their diameters are vastly different. I know that the two copper ...
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Temperature gradients and different types of wires in thermocouples
I use long (10-m) copper-constantan thermocouples for work to measure temperature. The temperature gradient is only present in the 15 cm nearest the hot junction; the remaining 9.85 m of these ...
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