egt wire splice

[paolomarks]

I tried hooking the wires up in all possible ways and my readings were always way low.  Like half what they're supposed to be.  I talked to the tech guy at Westach and this is what he said:



  "You don't want to use thermocouple wire to extend our leads.  The gauge is calibrated for the 4 foot sender type K . If you use thermocouple wire you will add added resistance into the system, that is why you are getting low readings.  You want to use standard 18 gauge copper wire to extend.   You can use up to 20 feet before it affects the readings enough to be noticed."
 

He also said soldering is not a problem.   Paolo

[Syncroincity]

  That is exactly the opposite of conventional wisdom regarding thermocouple extensions. WTF? I guess Westach instruments are designed specifically to use regular wire as extensions.

[Powjetta]

I'll have to dig mine out, but I bought the thermocouple probe and an extension from aircraft spruce, designed to work together.

[theman53]

that is what I told you in the TDI thread. Whenever I talked to the guy though he didn't say I could solider. I only used about 4 foot of the K type so I was good. The other thing is when you ask them to buy the 18gauge wire to extend, they didn't have it, at least for me they didn't.

On another note, the aircraft spruce micro 1000 probe says that it is calibrated to adjust for ambient temp. When used correctly with K type thermocouple and acceptable gauge...that is why I used the K type as well.

[92EcoDiesel Jetta]

IIRC that is exactly how mine is hooked up. Red to yellow and white to red.

I checked mine by sticking a lighter up to the probe and watching the gauge.

The best way to check for accuracy (at sea level) is with iced water and boiling water. 32 F and 212 F is what you should see.

[Toby]

Do you really think an EGT gauge is going to have a reading for 32*F ;<)

212* is also going to be right at the bottom of the scale, so it won't tell you much either. I don't think I would worry too much about checking the calibration of a new gauge. If I were concerned, I would call the manufacturer and as him how to check it. I would suspect that using a flame of a know temperature and heating the probe to equilibrium and seeing what the gauge reads is how they do it.

[theman53]

I was just meaning to see if the gauge was moving the correct way, not really calibrating it. I had mine hooked up wrong and the needle started to move below zero with the lighter. Quick switch of the wires and it is all good now.

To see if it was reading somewhat accurately I used an infared gun and a torch. It wasn't a real accurate way as there would be heat loss in the open air and what not, but I got it to read within 25F of eachother. I figured it close enough.

[92EcoDiesel Jetta]

"Do you really think an EGT gauge is going to have a reading for 32*F ;<)"

YES, it should be within +/- 3 to 4 degrees.

"212* is also going to be right at the bottom of the scale, so it won't tell you much either. "

It will tell you if it's going to be off at the higher temperatures

"I don't think I would worry too much about checking the calibration of a new gauge. If I were concerned, I would call the manufacturer and as him how to check it."

I called a manufacturer (Auber instruments) and they told me to use iceed water and boiling water.

"I would suspect that using a flame of a know temperature and heating the probe to equilibrium and seeing what the gauge reads is how they do it. "

Calibrating at the higher temperatures can only make the calibration better but the equipment needed will be a lot more expensive than iced water and boiling water.
 

[92EcoDiesel Jetta]

I was just meaning to see if the gauge was moving the correct way, not really calibrating it. I had mine hooked up wrong and the needle started to move below zero with the lighter. Quick switch of the wires and it is all good now.

To see if it was reading somewhat accurately I used an infared gun and a torch. It wasn't a real accurate way as there would be heat loss in the open air and what not, but I got it to read within 25F of eachother. I figured it close enough.

To see if the gauge is moving in the right direction, just put your fingers on the probe. it should rise if the ambient is below 90 F

[Toby]

This is an EGT gauge we are talking about. On my VDO the scale starts at 100*. You are going to have to heat it to at least 300* to get it to move.

[92EcoDiesel Jetta]

This is an EGT gauge we are talking about. On my VDO the scale starts at 100*. You are going to have to heat it to at least 300* to get it to move.

What p/n is that EGT gauge? I'll make sure to never buy one. Thermocouples can read accurately down to 0 degree  and lower. Whoever makes your EGT gauge had to do more work to not display temps below 100*. Don't know why they'd do that.

[Toby]

Like I said its a VDO. Its in the dash. Came with a Banks kit in my F-350.  EG temps below 100* just mean that the engine is not running. They are meaningless.