EMD 645-16 Exhaust Pyrometers

[FuelSquasher]

Hello all, thanks in advance for any help y'all can give.

I'm running a 645-16 turbo in a marine application. We've been trying to figure out exactly what kind of thermocouples this unit uses and none of my manuals are any help besides a part number. I have a panel mounted electronic reader that is adjustable for multiple types of junction but none seem to reflect a realistic exhaust temp.

The type K junction setting is the most accurate while the engine is stopped (with jacket water preheat both on & off) but under full load at around 900 rpm they show around 1100f which seems ridiculous since the infared gun shows about 600f on the manifold.

So does anyone here know what type junction they are or if there should be supplimental resistors or something similar in the circuit?

The pyrometers we are using are EMD part# 9310243.

Thanks again for any help.

[RickRackstop]

1000 Deg. F to 1100 Deg. F is about right for an engine at full power. Remember you are reading the exhaust temperature between the exhaust valve and the turbine inlet. After the turbo is done with it it should be about 750 deg, F.

[FuelSquasher]

That's surprisingly high, not that I'd doubt someone who knows those engines better than I do. That's quite close to glowing cherry red steel even.

So can you confirm that those thermocouples are indeed K-type?

[RickRackstop]

EMD only used one type of thermocouple that I know of (p/n 8462981), a matching pyrometer was shipped as part of the order.

Why don't you take a reading by dunking a thermocouple in boiling water to see if you are close to accurate or check with ABS to see what calibration method they would use.

[FuelSquasher]

You'd think that would've occurred to me.

I'll give it a try and report back, thanks again.

[FuelSquasher]

I didn't do the boiling/icewater calibration but our EMD guy funally got back to us and informed us that our previously listed thermocouple is type J.