can I? the pyro wires that came with my msd gauge are on the short side and the way im going to mount the gauge i dont think it will reach the passenger manifold. so will cutting and splicing in the extra wire effect my readings at all?
Cut thermocouple wires...
- Thread starter Redbowties88
- Start date
F***
thanks for that info bro... maybe someone else will chime in to cement that information
It is not so much calibrated, but the wire is special (I can not remember right now what it is made of). If you use a regular copper wire to make the extension, the readings will be off.
You would need to use thermocouple wire of the same type as the thermocouple (usually K type for our type of application).
You also have to use splicing material that is the same material as the wire. I believe that using solder to make the connection will also screw up the readings.
It is a PITA to extend thermocouple wire.
You would need to use thermocouple wire of the same type as the thermocouple (usually K type for our type of application).
You also have to use splicing material that is the same material as the wire. I believe that using solder to make the connection will also screw up the readings.
It is a PITA to extend thermocouple wire.
That's what the Autometer tech told me. So mine Pyro is tapped in the passenger side uppipe so it will reach to my over-mirror mount.
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Are you sure there is not a shorter way to route it? I feel like length shouldnt be a problem? Especially since it is for a specific application. I sure would hope the measured before they sold them anyways
Buy a longer wire, do not cut the wire on a pyro lead, it will not read right if it read's at all.
When you take two dissimiliar metals and heat them, they generate voltage. Even at room temperature, they make a certain voltage based on the two metals. So as long as you do not alter the type of metal that it was calibrated to, you should be OK regardless of length. So absolutely do not just grab any wire to extend it. They make extension wire for that specific purpose that is the same alloys. I think it's Cu and AlFe or something like that.
I was of the understanding that increasing the length of the wires on a given pyrometer would throw the reading off because of resistance increase with longer wire.
thanks guys im gonna try to make it work....the only way it will reach is if i drill a hole in the floor or firewall somewhere to run it which is what i was trying to avoid...but looks like thats whats gonna happen.....
its an msd dual laser by the way.... and strangely the probe is only 1/8
its an msd dual laser by the way.... and strangely the probe is only 1/8
yea i had to delay the project but im gonna try to tackle it today or tomorrow...im sure ill find a nice spot to drill
The wire type is Alumel and Chromel not sure on the spelling but that is the wire type on the turbine engines I work on. I would try to buy a longer wire.
yea im just gonna drill a hole in the truck and run the wire direct...
thanks though its good info to have
FWIW.
The dissimilar metals vary from thermocouple type totype but are the same within that type. K's are Nickle-Chromium(+ lead) and Nickle-Aluminum(- lead) which are marketed under a variety of trade names.
A cold junction between these metals creates a well understood and behaved temperature sensitive resistor. Which just means you measure the voltage drop across the junction and you can determine the temperature. (no Pat, it does not create it's own voltage)
The part that gets people in trouble is that a cold junction with any other metal, including copper, solder, or whatever, creates yet another temperature sensitive junction that influences the temperature reading. That means you must use wire made of these same exotic metals to make an extension if you want the thermocouple to work correctly.
The extension wire is actually rather cheap and can be gotten from Omega, Summit, Autogauge, and so on. Just make sure you match wire type to wire type and simply twist the wires together. Do not use a splicing device unless it is specifically designed for that thermocouple type. Do not solder!
The dissimilar metals vary from thermocouple type totype but are the same within that type. K's are Nickle-Chromium(+ lead) and Nickle-Aluminum(- lead) which are marketed under a variety of trade names.
A cold junction between these metals creates a well understood and behaved temperature sensitive resistor. Which just means you measure the voltage drop across the junction and you can determine the temperature. (no Pat, it does not create it's own voltage)
The part that gets people in trouble is that a cold junction with any other metal, including copper, solder, or whatever, creates yet another temperature sensitive junction that influences the temperature reading. That means you must use wire made of these same exotic metals to make an extension if you want the thermocouple to work correctly.
The extension wire is actually rather cheap and can be gotten from Omega, Summit, Autogauge, and so on. Just make sure you match wire type to wire type and simply twist the wires together. Do not use a splicing device unless it is specifically designed for that thermocouple type. Do not solder!