Pyrometer

[93_Fummins]

Quoted from Autometer installation instructions:

2. With the probe installed, the wire harness can now be routed to the gauge. The wire harness is an integral part of the pyrometer
calibration. It may not be shortened or lengthened without affecting the gauge calibration."

If I'm not mistaken, that's because Autometer gauges use stepper motor movements on their electric gauges and are calibrated for specific voltage inputs down to a few decimals. The other reason they suggest that the lead wires not be altered in length is that not everyone has Nisil or Inconel splicing couplers to splice the wires back together. Any different metal introduced in the communication path of the thermocouple will affect the reading as the current goes through the different resistivities. From what I understand, the introduction of a copper splice connector will throw off the readings more than the actual alteration in length. At least that is what I understand from my experience being an intern in a thermocouple manufacturing facility...

[Ace]

So I suppose it might be useful to know if that gauge the OP is asking about is of the stepper motor variety, then...

Maybe the Autometer instructions should be modified to say the wires "may be shortened or lengthened only by using Nisil or Inconel splicing couplers..."

Don't tell us your Fummnis lacked a thermocouple while you worked at a thermocouple manufacturing facility!

[Ace]

I... Type K wire isn't sensitive to length differences.

Just curious Philip, exactly what is "type-K wire? Is it related to that Nisil stuff 93Fummins mentions? Can I get it at True Value Hardware?

[meby]

So I suppose it might be useful to know if that gauge the OP is asking about is of the stepper motor variety, then...

The gauge was manufactured by S.S. White Technologies. Thats all I know.

[93_Fummins]

Don't tell us your Fummnis lacked a thermocouple while you worked at a thermocouple manufacturing facility!

Trust me, one of the first mods I made was a thermocouple...and I have a few spares just in case

Just curious Philip, exactly what is "type-K wire? Is it related to that Nisil stuff 93Fummins mentions? Can I get it at True Value Hardware?

Correction on my part: Type K thermocouples and lead wires are made up of a positive Chromel wire and a negative Alumel wire. The sensors I worked with were the super-high temp probes used in industrial DPF systems and they used Inconel and Nisil wires. Same concept, different materials... I'll let someone else chime in on how it works though, because I'm through being mocked......for now

[Ace]

Well, at least we got to the crux of the matter before making the old "don't worry, it's all good" call. And for the record 93, it was not my intention to mock you - just a lame attempt at humor....

[Ace]

Not knowing exactly what sort of gauge we're talking about, anyone still not leaning in this direction?

I'd ask where the lead wires are. They are a matched set and need to be of a certain length.

[Begle1]

Shooting from a hip, would it be correct that pyrometers with only the thermocouple inputs would be much more sensitive to wiring differences than pyrometers with a 12 volt supply on top of the thermocouple inputs?

[PToombs]

Since it comes with 2 thermocouples and the guage, just make the lead wires the same length for each. Doesn't sound like rocket science to me.
But then, I'm not a rocket scientist!

[Richie O]

Since it comes with 2 thermocouples and the guage, just make the lead wires the same length for each. Doesn't sound like rocket science to me.
But then, I'm not a rocket scientist!

We know what you are Pete.





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[PToombs]

I should drive that truck to SOP. Problem is I'll end up working all the way and be too tired to do anything.

[Philip]

Here you go Ace.

http://www.omega.com/ppt/pptsc.asp?ref= ... nav=temh07

Type K thermocouples are the most standard types used on American injection molding machines. The Jap presses like to use type J. German are a mix of both types. It depends on the MFG.

That is a 25' spool in that add. If you hook up a 2' section and do a reading. Then hookup a 25' section the reading won't be off more than 10 degrees or so.

[Ace]

Fair enough Philip, but it still may need to be specific (length) to the gauge you are connecting it to.

Personally, unless there is some way to verfy the wiring requirement on gauge itself and if it didn't come complete with all the wiring, I wouldn't buy it. JMHO. And on a side note, I don't care much about post turbo temps either. Maybe you guys should offer Meby to re-purchase it from him at cost if he can't get it wired right. Sorta like a wiring gaurantee?

[meby]

Personally, unless there is some way to verfy the wiring requirement on gauge itself and if it didn't come complete with all the wiring, I wouldn't buy it. JMHO. And on a side note, I don't care much about post turbo temps either. Maybe you guys should offer Meby to re-purchase it from him at cost if he can't get it wired right. Sorta like a wiring gaurantee?

Sounds good to me. Any takers?

Given the choice of only one, I would always put my pyro pre turbo. I just happened to run across this one on ebay and thought it would be cool to have one on both sides given that the cost on this gauge is approx. the same as my other choice (autometer). A two for one kind of thing.

[PToombs]

Matt, put the 2nd probe in the other truck and then you'll know what both are reading at the same time!