Specs on Long-Life GRT EGT Probe?

[SMO]

I had a EGT probe failure and will replace all 6. I see GRT sells a long-life probe with a 5 year warranty but they don't show the specs. I can call them on Monday but wondered if anyone already has this information. I would like to know the material (Inconel?), the response time in Ms, and the accuracy in %.

This probe only had ~200 hours on it although to be fair it survived an off airport landing that totaled the airplane before it spent the last 50 hours in mine.

[BillL]

Looking at the Omega site here are specs for high temperature thermocouples.

http://www.omega.com/Temperature/pdf/TJ36-XCiB_chb.pdf

After looking, I wonder why one would be made without Inconel sheathing?

Have others had issues like the OP photo, oxidation and failure?

[SMO]

Bill, are you saying the GRT long-life units are Omega's? Or are you just using this as an example of specifications?

The Sensor Connection has more complete specs and I am contemplating buying these. I would rather support GRT, however I want to compare specs first.

http://thesensorconnection.com/sites...Sheet_Rev4.pdf

[BillL]

Originally Posted by SMO

Bill, are you saying the GRT long-life units are Omega's? Or are you just using this as an example of specifications?

The Sensor Connection has more complete specs and I am contemplating buying these. I would rather support GRT, however I want to compare specs first.

http://thesensorconnection.com/sites...Sheet_Rev4.pdf

No, sorry did not mean to mislead. The Omega is trusted in test cell applications and they perform very well. This was a reference for the materials and wire temp capability. I certainly understand your expectations to define specifications first. I will follow with interest to better understand what is offered for our application.

Cheers!

[rzbill]

Hi Bill,
Yeah, the lower priced GRT EGT sensors fail pretty early. I had 2 go off at around 200 hrs and when I started searching here I found others had the same issue. Replaced with the long life units but have not passed an equivalent 200 hrs yet. I bought 4 expecting the rest to go soon.

Interesting that 2 of the low life sensors are still hanging in there at 325 hrs. (can you say "I just jinxed myself???")

[6 Gun]

Read a post on VAF about how to roll your on from Heating and Air gas units and it was very good price wise.Maybe someone with that experience could give specs for a really good DIY project.
Bob

[SMO]

Specs on the GRT long life probe:

Probe sheath material - Hastelloy
Response time - varies but is a grounded unit so should be faster than non grounded.
Temp Range - 0 - 2200*
Accuracy - within 10* at 1350* (.75%)
Probe depth is 1", non adjustable (perfect for a 2" pipe)
Warranty - 5 years

I will proceed with these.

[Lenny Iszak]

Alcor makes nice probes, but they are grounded. Not sure what GRT uses. I tried using them with AFS and they were jumping all over the place. Expensive mistake. So make sure you get the right type for your engine monitor.

Lenny

[SMO]

As I understand it the only issue to be sure to get right is the type of probes. I have a GRT EIS which uses the "K" type - usually designated by yellow and red wires.

All the Alcor probes I looked at were quite a bit more money than the competition.

Grounded probes respond faster than ungrounded and can cause "jumpiness" because of this as well as ground loops. The jumpiness can be resolved by decreasing the resolution by a factor of 10 on the display, but of course that defeats the value of the faster response. Grounded probes are somewhat less accurate than ungrounded - plus/minus ~10* versus ~5* (@ 1350*) according to the specs I looked at.