Hey guys -

I just started hopping some rides in a Piper Saratoga II HP and I've got a question mainly focused on a digital EGT gauge that is installed.

First off, I'm trying to identify it. It looks just like a J.P Instruments digital CHT gauge, with the yellow calculator-like bar graphs, but it's not the EDM-700. There are a few differences. First, at the top of the instrument, the left side says "EGT" and the right side says "CHT". Then, on the right side, instead of having "% Max" it has a temperature scale that tops at 500 degrees. The left side of the gauge just has some hash scale marks. There is a single button on the bottom left (which I have NO idea what it does, except for make the bar graphs flash every now and then.)

So first, does anyone recognize this gauge? I can't find any manufacturer on it, and I don't have a picture handy.

Secondly, the yellow bar graphs for each cylinder always have a blank bar, similar to the EDM-700. What does that black spot indicate? EGT or CHT?

Thirdly, how can I best use this instrument? Are there ranges I should shoot for? Is there a way it can help me lean? I really want to figure out the best/safest way to run this IO-300 engine (any additional information on THIS would be great too...)

Thanks!
Saint