can you shorten thermocouple wires

As long as you use the same type thermocouple wire and connectors (ex K), you can shorten or extend. Just do not use regular cooper wires or pins. Thermocouples

create a voltage proportional to a difference between hot and cold end, so the unit thermocouple plugs into needs to compensate for Cj

Full Answer

Can thermocouple tips be shorted to ground?

It all depends on the kind of chip you're using to amplify the thermocouple signal. For instance, the MAX31855 (which already includes the amplifier and a 14 bit ADC) does not allow shorting the tips to ground, while the AD8494 is ok by it, as long as there is only one point along the wires to which ground is connected.

Can you run thermocouple wire in Conduit?

Do not run thermocouple leads in conduits that carry power wiring. And do not run conduit carrying thermocouple leads parallel to electrical buss bars or heavy power-carrying conduit. Cross them at right angles. There are also a few tips to consider when you’re buying thermocouple wire.

What are thermocouple connectors and how do they work?

These connectors consist of a male plug and a female receiver pair and can be placed anywhere along your thermocouple wiring. With these connectors, you can join extension grade wire to thermocouple grade wire, or connect two lengths of extension wire to make it into one long piece. These make it incredibly easy to swap out worn thermocouples.

Why don’t thermocouples lose power along their length?

In other words, thermocouples do not experience “voltage drops” or power loss along its length as a high current power line might possess. The reason for this is due to the very low current and voltages associated with temperature measurements and that the thermocouple wire becomes the voltage source.

Does the length of a thermocouple wire matter?

The length of a thermocouple has no effect on its measurement accuracy or its ability to transfer the signal to the instrument. In other words, thermocouples do not experience “voltage drops” or power loss along its length as a high current power line might possess.

Can you splice a thermocouple wire?

YES. Temperature probes must be extended with thermocouple wire.

How long should a thermocouple wire be?

What is the maximum length of thermocouple wire? There are many factors that can impact the usable length of a thermocouple. As a guideline, under 100 feet with 20 AWG or thicker wire in an area free of electromagnetic interference usually is fine.

Can you cut K type thermocouple?

You can cut it down as much as you want, all that matters is that the right metals are in contact. Re: Type-K Thermocouple - Affects of shortening leads.

Can thermocouple wires touch?

If any of the thermocouple wire came into contact with another conductive material, electrons would escape from the thermocouple and give us inaccurate voltage reading. Touching the wires with each other would also create an open circuit which messes up the output votlage.

What happens if you wire a thermocouple backwards?

If you accidentally reverse the polarity of the thermocouple lead wires, the measured temperature will be incorrect by the difference in temperature of the two ends of the leads.

Should thermocouple wire be shielded?

When thermocouple wire leads must be shielded, use the shield connection provided at the input to the amplifier, and do not connect the other end of the shield (at the device under test) to a ground.

Are there different sizes of thermocouples?

Universal thermocouples come in lengths from 15 to 36 inches. An 18 or 24 inch will suffice for all residential water heaters using universal kits. Almost all older waters heaters and many of the newer style units with a sealed burner compartment and a viewing window will use this thermocouple.

How much of the tip of the thermocouple should flame envelope?

The flame should strong enough to cover about 1/2 inch at the end of the thermocouple tip. If the flame is too strong and not adjusted correctly, it will be blue and may make a hissing sound as the flame crosses the thermocouple. The pilot should be adjusted to reduce the intensity of the flame.

Can you bend a thermocouple?

Yes, you can bend your thermocouple probe. Bending the thermocouple probe will not harm the probe unless bent to excess. Bending the thermocouple probe will allow for a more accurate reading in most cases, compared to when just the tip of the probe is sitting in the solution or vapor you are trying to monitor.

How can I make a thermocouple at home?

0:073:15How to Make a Thermocouple - YouTubeYouTubeStart of suggested clipEnd of suggested clipSo the first step to making a thermocouple is to take the wire and split. It in half and this isMoreSo the first step to making a thermocouple is to take the wire and split. It in half and this is easily done with the razor blade. Now we can pull the two conductors apart.

Why do thermocouples fail?

After enough time, metal fatigue can cause a thermocouple to break. Thermocouples that are regularly exposed to extreme heat stress or extreme conditions are more likely to go through metal fatigue. If thermocouples start to give out unusual readings, it may be suffering from metal fatigue.

Can I extend thermocouple wires?

Do not extend the lead wires with compensating conductors that do not suit the characteristics of the Thermocouple, or with ordinary lead wires, as this would prevent proper temperature measurement. Be sure also to connect the wires using the correct polarity (+/-). Use lead wires with thick conductors for extension.

Can you repair a thermocouple?

Thermocouples are designed to detect a pilot light's loss of heat and close the gas valve to prevent a gas leak. Replacing a thermocouple is a relatively easy fix that can take less than two hours.

How do you connect a thermocouple wire?

0:524:01Basics for Thermocouple Connection- How to wire thermocouplesYouTubeStart of suggested clipEnd of suggested clipHead similarly white wire of extension cable need to be connect to positive terminal of thermocoupleMoreHead similarly white wire of extension cable need to be connect to positive terminal of thermocouple head and red wire of extension cable need to be connect to negative terminal of thermocouple.

Can I use copper wire to extend a thermocouple?

Thermocouple extension wire should ONLY be used to connect thermocouples to instrumentation, and copper wire should never be used. If you're wiring a thermocouple into a switch or junction box, the contacts do NOT need to be the same as the thermocouple materials.

Shortening thermocouple wire

I am replacing my westach quad gauge with a MGL EMS-2 engine monitor that allows 4 cylinder monitoring which the westach does not provide. Instead of looping up excess thermocouple wire (CHT and EGT) like I have done in the past, I would like to cut off the excess for custom lengths. Any problem with doing this? Bruce N199CL

Re: Shortening thermocouple wire

I'd recommend against cutting the lead because in the process a person may end up creating a "cold junction" which may alter the resistance value of the assembly, or introduce another bimetallic junction, of the manufactured part. In other words - it might not read predictably with the design value.

Re: Shortening thermocouple wire

The measurements we use on our engines are not that critical. If they were, manufacturers would be requiring cold junctions and/or chrome and alumel contacts in the connectors. You can shorten the leads without any major effect. I work on an experimental 747-200 that has a LOT of this wire installed on a couple hundred thermocouples.

Re: Shortening thermocouple wire

Thanks Jeff good to know that this can be done , as Dave mentioned above from what i've read , this is like voodoo science and its tough to get a definitive answer. Hopefully my MGL stuff arrives this week and I will talk to their tech support after seeing what the thermocouples look like. Can't wait to see your monster Kitfox fly.

Re: Shortening thermocouple wire

Thanks Bruce! Final push is under way... For what it’s worth, I was reviewing my documentation to ensure I understand how all of this is supposed to work and re-read my GRT EIS manual and it also mentioned it was ok to trim the wire lengths.

Re: Shortening thermocouple wire

As long as you use the same type thermocouple wire and connectors (ex K), you can shorten or extend. Just do not use regular cooper wires or pins. Thermocouples create a voltage proportional to a difference between hot and cold end, so the unit thermocouple plugs into needs to compensate for Cj

Re: Shortening thermocouple wire

Once you get your new gage installed and have some time on it - would appreciate a review of what you think of it. I too would like to set up CHT/EGT for all four cylinders.

What gives the thermovoltage?

Functionally: the contact of the two different metals is indeed what gives the thermovoltage.

Can you cut wires without losing calibration?

Yes, you should be able to cut the wires and reattach them without losing calibration. I wouldn't necessarily just twist them up, though. A weld would be best, and brazing second best ( http://eleceng.dit.ie/gavin/Instrument/Temperature/Laws%20of%20ThermoC.html -- the law of intermediate metals can be used to show this).

Is soldering a bad idea?

Soldering is a bad option. You shouldn't worry much about "calibration", especially for the soldering iron application, because the voltage output is determined by metal alloy compositions of the two wires, and by nothing else.

Can a little metal ruin a thermocouple junction?

Well it turns out that if both junctions A-B, and B-C are at the same temperature the effect of B cancels out, and it's equivalent to A-C. So no, a little metal from your pliers will not ruin the thermocouple junction.