How does a thermocouple work

How does a thermocouple work

What is the working principle of thermocouple? The principle of the thermocouple. The voltage is measured to derive the temperature. In practice, leads A and B are connected to a digital voltmeter (DVM), digital multimeter (DMM), digital data acquisition system, or other voltage measuring device.

What is the purpose of thermocouple?

A thermocouple is basically a device that measures temperature. Unlike a thermometer, which relies on the thermal properties of a material such as mercury, a thermocouple measures temperature by generating an electrical voltage.

How accurate is thermocouple?

Thermocouples are used in an extremely wide temperature range (see Table 1). The electromotive force of a metal conductor thermocouple is typically 5 to 60 millivolts. The accuracy of the temperature display is usually within a few degrees K. Some thermocouples are accurate to ~° K.

What kind of energy is a thermocouple?

A thermocouple is a converter that converts thermal energy into electrical energy and consists of connecting wires of different metals to form a connection. Voltage is generated when the temperature changes across the junction.

Patio heater thermocouple

What is the purpose of the thermocouple?

A thermocouple is a sensor that measures temperature. Thermocouples consist of two metal legs of different metals. The legs of the cables are soldered together at one end to make a connection.

What is the range of thermocouple?

One of the most common types of thermocouple is the type K thermocouple. The general measurement ranges for type K thermocouples are 200°C to +1350°C. Type K thermocouple cannot be used outside this temperature range.

How do thermocouples work?

Thermocouples work by measuring the difference in voltage that occurs between two different conductors when those conductors are exposed to a difference in temperature. The generated voltage is measured internally and converted into temperature.

What is the working principle of thermocouple transducer

The operation of a thermocouple depends on three effects. Specular reflection effect. Specular reflection occurs between two different metals. When heat is transferred to one of the metals, electrons begin to move from hot to cold metal. Therefore, a constant current is induced in the circuit.

What is the working principle of the temperature sensor?

This sensor consists of two different metal wires connected at the junction. In this regard, temperature can be measured and a change in temperature of the wire generates a voltage.

How does a thermocouple measure EMF?

The current or electromotive force meter is connected to the thermocouple circuit. It measures the amount of electromotive force flowing in a circuit due to two connections of two different metals at different temperatures.

What is the sensing junction of thermocouple?

A two-metal connection, called a semantic connection, is associated with extension cords. Two different metals can be used to make a thermocouple.

:brown_circle: What is the working principle of thermocouple design

Basic principle of a thermocouple A thermocouple works according to the principle of the Seebeck effect. Since Thomas Seebeck first discovered this effect, it has been called the Seebeck effect.

Hot water heater pilot light

:brown_circle: What is the working principle of thermocouple heater

The thermocouple principle is based on the reverse vision effect. This effect indicates that if a closed circuit is formed by joining two different metals at two contact points, and the contact points are held at different temperatures, an electromotive force is induced in that closed circuit.

What is the working principle of thermocouple in water

The working principle of a thermocouple is based on the Seebeck effect (see thermoelectric phenomena). A two-metal connection, called a semantic connection, is associated with extension cords. Ambient temperature, Ta. Consider the following setup with six thermal connections, two in each constant temperature bath.

What is a thermocouple for water heater?

Many people explain what a thermocouple is, but they may not be aware of one of the useful uses of this device - a thermocouple for water heaters. The thermocouple is the preferred transducer, which in some cases can be combined with a gas oven. It is used to know if the pilot is activated or not.

What is the use of thermocouple in thermometer?

Therefore, a thermocouple is used to measure the temperature. Since it converts a non-electrical quantity (temperature) into an electrical quantity , it can also be used as a converter. Since it does not require a power supply to function, it is a secondary converter.

Rheem water heater troubleshooting

:diamond_shape_with_a_dot_inside: How do thermoelectric circuits work?

When two wires of different metals are connected at both ends and one end is heated, a direct current flows through the thermoelectric circuit. When this circuit is broken in half, the net open circuit voltage (Seebeck voltage) depends on the junction temperature and the composition of the two metals.

What is the working principle of thermocouple energy

Thermocouple working principle The thermocouple working principle is based on the reverse view effect. This effect indicates that when a closed circuit is formed by connecting two different metals at two contact points and holding the contact points at different temperatures, an electromotive force is induced in that closed circuit.

:eight_spoked_asterisk: What is the working principle of thermocouple temperature

Definition: A thermocouple is a device for measuring temperature. They are active inverters because they work on the principle of energy conversion. They do not require any food to function.

What is a thermocouple used for in the home?

Thermoelectric pair. Applications include temperature measurement of furnaces, exhaust gases from gas turbines, diesel engines and other industrial processes. Thermocouples are also used in homes, offices and businesses as temperature sensors in thermostats and as flame sensors in safety devices for gas appliances.

:eight_spoked_asterisk: How do you wire a thermocouple?

  • In the US, RED is always negative when connecting thermocouple leads to instruments. Other
  • Match the thermocouple wire to the type of thermocouple being used.
  • Use thermocouple wire to make thermocouple elements or to connect thermocouples to instruments. Thermoelectric Couple
  • When connecting a thermocouple to a switch or junction box

:diamond_shape_with_a_dot_inside: What is a thermocouple on a water heater?

A thermocouple is a thermoelectric device that shuts off the gas supply to the water heater if the pilot flame fails. The function is simple, but very important for security. A thermocouple when heated with a flame generates a small electrical current. This small amount of electrical current keeps the pilot throttle open.

:diamond_shape_with_a_dot_inside: What are the applications of thermocouple?

Applications of Thermocouples: Thermocouples are useful for measuring wide temperature ranges. The upper temperature range is 2300C. With the thermocouple you can measure exhaust gases from gas turbines, blast furnaces, diesel engines and fog machines.

:brown_circle: What is the purpose of a thermocouple on a water heater

A thermocouple is a thermoelectric device that shuts off the gas supply to the water heater if the pilot flame fails. The function is simple, but very important for security. A thermocouple when heated with a flame generates a small electrical current.

Thermistor vs thermocouple

:diamond_shape_with_a_dot_inside: How do you remove a thermocouple from a gas water heater?

On older pilot water heaters, removing and replacing the thermocouple is very simple - after disconnecting the igniter tube, burner supply tube and thermocouple from the gas control valve, simply lift the burner and remove the bottom of the water heater.

How does a thermocouple work in a water heater?

This is how a thermocouple works. The thermocouple in a gas boiler consists of two different metals, which are connected in such a way that when heated with a pilot flame, a small electric current is created. Then an electric current feeds an electromagnet in the gas valve and keeps it open.

What does the thermocouple do on my water heater?

The thermocouple is part of the pilot burner and is connected to the gas control valve outside the boiler. It is a simple device that converts the heat from a burning flame into a weak electrical current, thus acting as a switch to regulate the flow of gas from the gas supply valve.

:brown_circle: What is the purpose of a thermocouple in a gas fireplace

A gas fireplace thermocouple is often found under modern gas fireplaces. The thermocouple is an electronic safety device. It is used to ensure the safety of the ignition system and prevent fuel leakage.

:eight_spoked_asterisk: How do you clean a thermocouple on a gas fireplace?

Completely shut off the fire gas and allow the thermocouple to cool for half an hour before touching it. Take an Allen wrench or screwdriver and loosen the items holding the two thermocouple wires in place. Some models use hex nuts, others only use bolts.

How to tell if a thermocouple is bad?

  • The first are signs of pipe contamination, including discoloration, cracks, or small holes.
  • Then check the wiring for signs of wear or corrosion, such as: B. lack of insulation or bare wire.
  • Finally, visually inspect the connections for physical damage, as a broken connection can affect the validity of the test.

:diamond_shape_with_a_dot_inside: What is a thermocouple in a fireplace?

The thermocouple in a gas fireplace can often be found under modern gas fireplaces. The thermocouple is an electronic safety device. It is used to ensure the safety of the ignition system and prevent fuel leakage. Most gas burners have a start mode to heat the thermocouple. No gas may enter the burner in this operating mode.

Do gas fireplaces put out much heat?

1 answer Gas fireplaces give off heat, but the amount depends on the type of glass and the BTUs used. A fireplace with an input power of 21,000 BTUs and an efficiency of about 70% can heat up to 1,000 square feet in an average home.

Wall Heater Thermocouple Replacement

:brown_circle: What is the most accurate thermocouple?

Type K Thermocouple (Nickel Chromium / Nickel Aluminum): Type K is the most common type of thermocouple. It is cheap, accurate, reliable and has a wide temperature range.

How accurate are thermocouples?

Thermocouple Accuracy The accuracy of a thermocouple depends on many factors, including but not limited to electrical noise and the purity of the metals used.

:eight_spoked_asterisk: What is the voltage of a thermocouple?

The voltage generated by a thermocouple is small, measured in thousands of volts (0.001 volts), and depends not only on the temperature difference, but also on the types of metals used in the thermocouple.

How accurate is a thermocouple test

However, as the voltage of the thermocouple changed, the voltage across the resistor also changed, causing the resistance value to change. Therefore, the resistance value can increase by about 20%. When using a portable multimeter, the accuracy is reported to be approximately 15% ± x ohms.

What type of thermocouple is best for air temperature measurement?

Open thermocouples are best suited for measuring air. Measuring the temperature of a solid surface is difficult for most types of temperature sensors. To ensure an accurate measurement, the entire measuring range of the sensor must be in contact with the surface.

When does a thermocouple need to be recalibrated?

Thermocouples are measuring instruments that can read very small temperature changes. As a result, they are widely used in applications where precision is paramount. However, as with any measuring device, thermocouple performance deteriorates over time with prolonged use. At this point, the thermocouple should be recalibrated.

What are thermocouples used for?

Thermocouples are measuring instruments that can read very small changes in temperature. Therefore, they are often used in applications where accuracy is paramount. However, like any measuring device, thermocouples wear out over time and prolonged use.

How does a thermocouple work on a gas furnace?

This rod connects to the gas valve on your stove. When your lighter ignites, the heat from the flame sends voltage across the thermocouple, leaving the gas line open. When the test lamp goes out, the thermocouple loses power and the gas line to your furnace is closed. How does a thermocouple make your oven safer?

How do you test a thermocouple on a gas furnace?

It is recommended to check and test the furnace thermocouple before proceeding with the repair. To check, press the red button, which should be on the control unit (you should see something labeled "Pilot"). This means that only the pilot can accelerate.

When should you replace your furnace thermocouple?

A working thermocouple gives readings from 25 to 30 millimeters. If the reading is less than 25 millimeters, it must be replaced. Call Raleigh, NC Furnace Thermocouple Repair Air Specialists!

How accurate is a thermocouple chart

Accuracy - In addition to the inherent inaccuracies of thermocouples due to their metallurgical properties, the measurement accuracy of thermocouples is as high as the measurable cold junction temperature, usually between 1°C and 2°C.

How accurate is a thermocouple sensor

A thermocouple is a sensor made up of two different metal wires connected at the end of the sensor. The measured voltage at the other end represents the measured temperature. While the accuracy may be slightly less than RTDs, they have the widest temperature range from 200°C to 1750°C and are generally cheaper.

What is a thermocouple sensor?

The thermocouple is a very popular sensor due to its relatively low cost, interchangeability, wide measuring range and reliability. Thermocouples are widely used in all industries from factory automation and process control to automotive, aerospace, military, energy, metallurgical, medical and more.

:brown_circle: How do Thermocouples measure thermal energy?

By keeping the cold junction at 0 degrees Celsius, the thermoEMF (electromotive force) of the thermocouple is measured during the transition from a fixed point where metallic materials change from solid to liquid. This electromagnetic force is then compared to standard measurement charts to determine the accuracy of the thermocouple measurement.

:brown_circle: Should thermocouples be calibrated?

Thermocouples are calibrated by comparison or fixed point calibration, depending on the thermocouple type, temperature range, and accuracy required.

What is the temperature range of thermocouple?

All types of refractory thermocouples have a temperature range of 32 to 4200 degrees Fahrenheit. These thermocouples are mainly used in vacuum furnaces with temperature ranges that exceed the temperature capabilities of platinum.

How accurate is a thermocouple for water heater

When a water heater thermocouple fails, learn how to replace it. The working thermocouple measures 25 to 35 millivolts. If it reads less than 25 millivolts, it's time to replace it.

:diamond_shape_with_a_dot_inside: What is a thermocouple failure?

Thermocouple failure is a common problem with domestic gas water heaters. A thermocouple is a thermoelectric device that shuts off the gas supply to the water heater if the pilot flame fails. The function is simple, but very important for security.

What happens if you don’t clean the thermocouple in a water heater?

Cleaning the thermocouple in the water heater is an important maintenance procedure. If this does not happen, the water will not heat up. Therefore, for the hot water supply, they show you how to clean the thermocouple of your water heater to avoid this inconvenience. What is a Thermocouple? How does a thermocouple work?

:brown_circle: What kind of energy is a thermocouple gas

First chapter. What is a Thermocouple? A thermocouple is a converter that converts thermal energy into electrical energy and consists of connecting wires of different metals to form a connection. Voltage is generated when the temperature changes across the junction.

Water heater troubleshooting

:eight_spoked_asterisk: How does a thermocouple produce voltage?

It creates stress when the temperature in the ■■■■■ changes. The thermocouple works with the Seebeck effect. Here (as mentioned) two wires of different metals are electrically connected at one end. When the barrier layer is heated or cooled, a voltage is generated which is proportional to the temperature.

:diamond_shape_with_a_dot_inside: What is the temperature range of type T thermocouple?

The temperature range of the T-type thermocouple is 330 to 700 F and the wire color code is blue and red. Type E Thermocouple - Nickel Chrome / Constantan.

:eight_spoked_asterisk: Do thermocouples need two different metals to work?

In order for a thermocouple to work properly, it must be made of two different metals to create a voltage. The sum of the emfs of two or more dissimilar metals is zero when the circuit has the same temperature. Adding different metals to the circuit will not affect the voltage generated by the circuit.

What is the relationship between voltage and temperature in a thermocouple?

Unfortunately, the relationship between thermocouple voltage and temperature is not linear and thermocouple temperature conversion tables must be used to determine the temperature from the measured voltage. The table contains an extract from the voltage/temperature table for a type K thermocouple (reference 0°C).

Water heater no hot water

How do you measure the temperature of a thermocouple?

The electromotive force of a thermocouple is measured with a high resistance voltmeter. Unfortunately, the relationship between thermocouple voltage and temperature is not linear and thermocouple temperature conversion tables must be used to determine the temperature from the measured voltage.

:brown_circle: What is the temperature range of a type K thermocouple?

The temperature range for Type K wire is 330-2300°F and the wire is color coded yellow and red.  Type N: The type N thermocouple has a positive nikrosil leg (nickel 14% chromium-silicon) and a negative nisil leg (nickel-silicon, 1% magnesium).

What kind of energy is a thermocouple symbol

Thermoelectric pair. A thermocouple is an electrical device made up of two different electrical conductors that form an electrical connection. Due to the thermoelectric effect, the thermocouple generates a temperature dependent voltage which can be interpreted as a temperature measurement.

How do you find the temperature T sense of a thermocouple?

A typical thermocouple configuration is shown in the figure. In summary, the required temperature Tsens is obtained using three inputs: the characteristic function of the thermocouple E (T), the measured voltage V and the reference junction temperature Tref. Solving the equation E(T-sentence) = V + E(T ref) gives T-sentence.

:diamond_shape_with_a_dot_inside: What is a type T thermocouple?

Type T thermocouples have copper as a positive leg and constantan as a negative leg with a temperature range of 330°F to 700°F and are color coded in red or blue.

:diamond_shape_with_a_dot_inside: What is the relationship between temperature and current in a thermocouple?

In other words, the Seebeck temperature-voltage relationship is fixed and the temperature-current relationship is variable depending on the total resistance of the circuit. With heavy enough thermocouple cables, currents of up to hundreds of amps can be generated from a thermocouple junction pair!

:eight_spoked_asterisk: What kind of energy is a thermocouple battery

A thermocouple uses the thermoelectric effect to do what it does. Thermal energy (heat) is converted into a potential difference, which is electrical (electromagnetic) energy. Home Science Mathematics and arithmetic.

What type of thermocouple is used for high temperature measurements?

Type B, R and S thermocouples are generally only used for high temperature measurements due to their high cost and low sensitivity.

Warm Morning Heater

What is the thermoelectric effect of thermocouple?

Thermoelectric effect. A thermocouple is an electrical device made up of two different electrical conductors that form electrical connections at different temperatures. Due to the thermoelectric effect, the thermocouple generates a temperature dependent voltage which can be interpreted as a temperature measurement.

:eight_spoked_asterisk: What kind of energy is a thermocouple for air conditioning

A thermocouple is made of two different metals. Usually in the form of two cables twisted, soldered or crimped together. The temperature is recorded by measuring voltage. By heating a metal wire, the electrons in the wire are excited and start moving.

:eight_spoked_asterisk: What metals are used in thermocouples?

Typical metals in thermocouples are iron (Fe), copper (Cu), nickel (Ni), constantan (Cu/Ni alloy), nichrome (nickel-chromium (Cr) alloy), and platinum (Pt). Each metal has certain advantages and disadvantages when measuring temperature with thermocouples.

How much electricity does an air conditioner use?

Three quarters of all American homes have air conditioning. Air conditioners use about 6% of all electricity generated in the United States, costing homeowners an estimated $29 billion a year. About 117 million tons of carbon dioxide are emitted into the atmosphere every year.

How To Light Rheem Water Heater Pilot

:brown_circle: What can I do to reduce energy use for air conditioning?

Switching to high-efficiency air conditioners and other home cooling measures can reduce air conditioning energy consumption by 20-50%. For general information about air conditioners and the best way to maintain them, see: The two most common types of air conditioners are room air conditioners and central air conditioners.

:diamond_shape_with_a_dot_inside: How does a thermocouple work on a gas pilot light?

A thermocouple when heated with a flame generates a small electrical current. This small electrical current keeps the pilot throttle open. When the pilot goes out, the electrical power is cut off and the throttle closes. Just don't light the flame, there is no gas flow.

What kind of energy is a thermocouple for furnace

Like other components in your furnace, a thermocouple can wear out over time and generate less voltage than when heated. Thermocouples can last for several years, but they generally don't last as long as the oven itself.

:diamond_shape_with_a_dot_inside: What does the thermocouple in my Furnace do?

The thermocouple is the protection of the oven. It has a metal rod that connects to the oven gas valve. When the thermocouple senses heat from the pilot, it holds the gas line open. When the pilot is out, the thermocouple senses heat loss and the stem closes the gas valve and shuts off the fuel supply.

How To Light A Propane Heater

:diamond_shape_with_a_dot_inside: Where is the thermocouple on a gas furnace?

The thermocouple is part of the gas combustion chamber located next to the pilot burner. This is a safety device that cuts off the gas supply in the event of the pilot or electric igniter failure.

Do all gas fireplaces use a thermocouple?

However, not all of these systems use a thermocouple. Some gas stoves rely on electronic ignition to ignite the flame. These devices generally do not use a thermocouple.

What is the difference between thermocouple vs thermopile sensor?

A thermocouple is a thermoelectric device and a thermopile is a device that converts thermal energy into electrical energy. This article provides a reference comparison for a complete understanding of a thermocouple sensor and a thermopile, and presents the key differences between the operation of a thermocouple and a thermopile.

How many volts does a thermocouple produce?

Each additional thermocouple in the thermopile increases the system's ability to generate electricity. For example, if a thermocouple produces two volts of electricity and a thermopile has five thermocouples, it can generate two volts per thermocouple for a total of eight volts.

Furnace wiring

:diamond_shape_with_a_dot_inside: How do you test a gas valve thermocouple?

How to check a thermocouple. If the pilot light does not come on, check the gas boiler thermocouple by pressing and holding the on/off button. Measure the current with a multimeter set in millivolts. One probe should be connected to the copper jacket of the thermocouple and the other to the gas valve.

How to test a thermocouple?

  • Remove the thermocouple. First remove the thermocouple from the affected device.
  • Choose a trial version. There are three different test methods that can be used to test a thermocouple.
  • With a multimeter.
  • Run the inactivity test.
  • Closed loop testing.

:brown_circle: How does a thermopile work

If it is a flame blocking model there is a small indicator to see the pilot light. If not, you can simply remove the lid and look around the room. If your heater shuts off after about a minute, it looks like the thermocouple is wearing out because it isn't generating enough voltage to keep the gas valve open.

:eight_spoked_asterisk: What is the function of a thermopile?

Thermopile. They are also widely used in heat flow sensors, pyrheliometers and gas burner safety controls. The power output of a thermopile is typically on the order of tens or hundreds of millivolts. In addition to increasing the signal level, the instrument can also be used to average the room temperature.

How does a thermocouple work in a boiler?

Boiler stoves usually have a thermocouple in an indicator light. Thermocouples work through the interaction of two dissimilar metals. When the temperature in the heating system changes, the two metals react with each other.

:eight_spoked_asterisk: What does a thermopile do gas fireplace?

In gas and heating fireplaces, thermocouples and thermopiles are mainly used to generate electricity. When burning, the gas stove's pilot burner generates heat, which passes through a thermocouple.

:brown_circle: How does a thermocouple work to produce

A thermocouple is an electrical device made up of two different electrical conductors that form an electrical connection. Due to the thermoelectric effect, the thermocouple generates a temperature dependent voltage which can be interpreted as a temperature measurement. Thermocouples are a type of temperature sensor that is widely used.

:brown_circle: How does thermocouple measure temp?

Temperature Range - Most practical temperature ranges can be used with thermocouples, from cryogenic to jet engine exhaust. Depending on the metal wires used, the thermocouple can measure temperatures from –200 °C to +2500 °C.

How To Change A Thermocouple On A Water Heater

:diamond_shape_with_a_dot_inside: What should the thermocouple resistance measure?

Always measure the resistance of the thermocouple outside the application so that the EMF output does not interfere with the ohmmeter reading. Long output cables or the use of analog devices make conductor resistance an important factor in choosing the best cable size for your application.

How to test a thermopile with a meter?

  • Remove the thermocouple first.
  • Second, turn on your multimeter and set it to ohms.
  • Third, light the flame and place the tip of the thermocouple over the fire.
  • After making sure the flash point is hot, take one wire from the multimeter and place it on the thermocouple rod and the other wire

How does a thermocouple work with solenoid

The thermocouple works in conjunction with the pilot and main gas valves. The valve is located in the control unit. A thermocouple consists of two wires welded together and enclosed in a housing. This cover fits over the hottest part of the pilot and the other end connects to the main gas valve.

What is a thermocouple on a gas pilot light?

The thermocouple consists of two wires welded together, enclosed in a housing. This box is placed in the hottest part of the pilot and the other end is connected to the main gas valve. The thermocouple acts as a sensor. Determines when the igniter is hot enough to ignite gas from the main gas valve.

:brown_circle: What are Thermocouple sensors made of?

Thermocouple sensors are made of wires, often called thermocouples, insulation, jackets, end seals, and connectors (extension cords, plugs, etc.). The wires are joined together at one end to form a "sense" or "hot" connection.

:brown_circle: Can a thermocouple open a gas or water valve?

A thermocouple cannot directly open a conventional gas or water valve. AFAIK the power source must always be external, either a power source or the pressure of the fluid itself.

How does a thermostat work

The room thermostat easily turns the heating on and off as needed. It works by sensing the air temperature, turning the heater on when the air temperature falls below the thermostat setting, and turning it off once the set temperature is reached.

How do I Set my thermostat?

Programming thermostat Read manual. Determine your schedule. Information about the time and date of the program. Press the "Install" or "Schedule" button. Press "set" or "program" again to set the temperature. Set the time and temperature to "hatch". Set the "return" time and temperature. Set the time and temperature to "sleep". Repeat the procedure on the weekend.

:eight_spoked_asterisk: How to check if thermostat is working?

Go to the thermostat terminals and see if there is power. Turn the lower thermostat off by turning the knob to the lowest position. Connect the multimeter leads to terminal 1 and the blue wire from the heating element. If the meter reads 240V, it means the device is turned on. Change to lower radiator thermostat.

:brown_circle: How do you check a thermostat?

Check your thermostat to make sure it is in the on position. Make sure the thermostat is set to the correct heating or cooling settings. Check the programmable thermostat locks to make sure the locks are not interfering with thermostat operation.

How does a thermostat control the temperature?

The thermostat has a temperature-sensitive sensor that measures the temperature in the oven. The thermostat turns the heating on and off to maintain the desired temperature in the oven. There are different types of oven thermostats and they all have the same functions, but the type of oven determines how the thermostat works.

:diamond_shape_with_a_dot_inside: How does a thermocouple work principle

How Thermocouples Work When two wires of different metals are connected at both ends and one of them is heated, a constant current flows through the thermoelectric circuit.

How Much To Replace Water Heater Thermocouple

How do thermocouples generate voltage?

Thermocouples don't just generate electricity from heat. They can also generate heat from electricity and even cold from electricity, like a refrigerator. When two different wires are connected at either end and current flows from a voltage source through the loop, one connection will heat up and the other will cool.

:brown_circle: Why do thermocouples have two different metal wires?

Thermocouples work on the principle that each wire causes a voltage drop along its length when it heats or cools one end. Different metals develop different stresses. So if you connect two different metals and heat the junction, on the other side you can measure the voltage difference and determine the temperature.

how does a thermocouple work