Autometer Pyro question

[wbw189]

Hey guys,

I bought a used Autometer pyro. The leads were clipped about 2 inches behind the gauge. Will that affect how the gauge reads?

Thanks,

 

[SparkandFire]

Shouldn't matter, the only part of the thermocouple that produces the millivolt signal for the meter is the junction at the end, where both wires are butt welded together.

Just strip the wires, and solder them back (if possible)

Pay attention to the polarity of the wires, though! (If you get it wrong, the temp will read the opposite direction!)

 

[6 Nebraska IDIs]

Here is what i was told some time ago from an autometer tech. The thermocouple wiring (the entire harness) is sensitive to what the gauge will read. If a connection is faulty it will not read properly, if the wires are shorter or longer than they were originally intended to be it will not read properly, if a repair has been done to the harness that produces even the slightest resistance it will not read properly. Buy a new harness from autometer or the gauge will not read properly. That is what I was told about 3 years ago when I bought a used one for my eclipse and it had a harness that had been cut just like yours.

 

[subliminal]

Here is what i was told some time ago from an autometer tech. The thermocouple wiring (the entire harness) is sensitive to what the gauge will read. If a connection is faulty it will not read properly, if the wires are shorter or longer than they were originally intended to be it will not read properly, if a repair has been done to the harness that produces even the slightest resistance it will not read properly. Buy a new harness from autometer or the gauge will not read properly. That is what I was told about 3 years ago when I bought a used one for my eclipse and it had a harness that had been cut just like yours.

keep in mind they are working for teh company that sells the harness.


if you can solder you souldnt have a problem. it would take a really crappy splice like if you just used butt connectors or twisted the wires together to get a 1mv drop. a good solder joint wont loose a thing.

 

[SparkandFire]

Typical solder joints are very low resistance, especially if you use a good silver solder. You are correct in the fact that any change to the thermocouple lead wire will affect the temperature reading, but the difference is quite minimal (between 1 and 2 degrees)

I'd be happy with an error of 1 degree, if it saves me spending $$$ on a new harness!

Just ask the E4OD guys about millivolt signals and connection points...

 

[suv7734]

Don't solder the connection. It introduces another metal into the system and will cause inaccurate readings. For thermocouples and thermocouple extension wire the only proper connections are mechanical ones. The length of the thermocouple extension wire will not matter until you get up to 2 or 300 feet (single run) as long as the connections are made properly.

 

[subliminal]

so the mecanical crimp connections aren't a different metal ? the last crimp connector i saw was aluminum. i still say soldering is choice but hey what do i know?

 

[SparkandFire]

I've always had good luck soldering and heat shrinking TC wires, and they always calibrate out fine.

Twist the TC wire together, then solder. Always works for me.

 

[wbw189]

Thanks, guys. Hopefully, I get to it this weekend. Christmas and AAU basketball are ramping up pretty quickly.

Later,