OPT-1

[Joshuajayg]

Made by Electronics Int'l

Anyone install or use the primary replacement oil temp and oil pressure gauge? I've got one on order that I will install next week. Never used one though.

 

[Joshuajayg]

Hmm, I guess this is an Avionics question. Admin?

 

[JohnAJohnson]

Yes Joshua, I installed an OPT-1 in my Cardinal a few years ago to replace the crappy Cessna primaries and to also get an annunciation when the pressure or temperature exceeded limits. I am mostly happy with it but if you night fly, you might want to also buy one of EI's dimmers specifically for it. The OPT-1 doesn't track a standard voltage changing dimmer well (found in most light airplanes). Here's some info on mine that shows how I wired the dimmer circuit (just go to the OPT-1 line item under Engine Instruments).

 

[Joshuajayg]

Thanks, John. This is a jump plane so night ops really isn't a concern for us.

I'll be looking to find a fuel gauge replacement eventually as well since two of the four rectangular instruments are unneeded. I see you have Aerospace Logic for those. How do you like it?

 

[JohnAJohnson]

Yep, that was my objective too - get rid of the four gauges next to the yoke. The Aerospace Logic unit is fantastic. I used Electronics International Magnetic Probes with it and they track great, and won't ever wear out. As you know, most resistance probes develop bad spots, or the wiper looses a firm contact with the windings, or the windings get dirty, etc. and you end up with inaccurate, intermittent readings. The magnetic probes solve this, but they require a 5VDC reference, so you'll need to string another wire out to each probe with 5VDC on it. The Aerospace Logic is also a pain to calibrate. You must add 2 gallons at a time to each tank, press some buttons, and repeat till the tank is full. But it is worth it and you only need to do it once. I still dip my tanks before flight and it always matches the quantity on the Aerospace Logic gauge. I also set the Aerospace Logic annunciator to activate if there is 7 gallons or less in either tank, so it's nice to have a "Check Fuel Quantity" in the headset (via the EI AV-17 bitchin betty) when I get low on gas.

 

[bnt83]

I have installed an aerospace logic fuel gauge, the instructions for calibration could have been written better to avoid the pitfalls of the procedure. I ended up defueling and refueling about 3 times to get it set up. Basically it told me to add fuel and hit the button, but you need to make sure it sensed a change in measured resistance, if it sensed the same thing twice it goes into error and there was nothing to be done but start all over. The last two gallons weren't measurable and I was trapped and had to do it over the next time I exited before entering the to cal for that last two gallons.

Overall I liked the instrument and owner loves it. Hopefully the cal procedure has been revised by now.