GEM CHT Probes

[Schinderhannes]

I just replace the GEM #2852 CHT probe in cylinder 4 with a GEM #2856 probe to keep the OEM CHT functional.  To my surprise the CHT for #4 reads now almost 100F lower.  The OEM gauge seems to read low as well. Has anybody had a similar experience when switching to the piggyback probe?

 

 

[Andy95W]

Yes, same experience, and it sucks because you know the digital is far more accurate than the OEM.

[JaredDavis]

I always wondered how close a non contact thermometer reading would be to the CHT gauge.

[Andy95W]

I always wondered how many people just use the standard probe and simply ignore the factory CHT gauge.

[carusoam]

The goofy part of accuracy with a non-accurate gauge is...

The red lines and other operating parameters are based on the old gauge's readings.

If you were to use a new or better technology, you would need to update the operating parameters to match.

Maintaining AW on a 50 year old airframe has it's challenges...

FBs (upscale for CBs) find a way to leave the old equipment in place for AW, and use the best technology available as a work around.

Sometimes a hangar fairy or pixie has been known to make temporary adjustments that can be returned to original status at annual time...(so I've heard)

The RB (wealthiest of CBs) alternative is to use a JPI (or equivalent) that can be used as a primary gauge and swap out the old ones...

Best regards,

-a-

Scale:

Cheap

Frugal

Rich

[Schinderhannes]

I just spoke with GEM technical support and they confirmed that the adapter probe will read lower, and recommended using always the same style probe for all cylinders.  The OEM gauge not working might be the better option....