Microwave Leakage Detector?

[MadManMarkAu]

I recently aquired a microwave oven from the local tip site, for the goodies (MOT, HV diodes, HV cap) to play with. Well, I found in it what I can only describe as some sort of leakage detector. I know how they work in theory, but not in practice. It has 2 components inside it with a common ground. 2 signal lines go to the micro board. How does this work (is it a redundancy thing?) and how would you make a driver circuit. Attached are a few photos of it.

[Q]

woa! that is wierd.
at first glance it kinda looks like a thermal fuse/breaker sort of thing.... i've taken many microwave ovens apart to salvage what i could and have never come across anything like that.
was this from an industrial unit?

Q

[MARK-HARRISS]

Looks more like an ultrasonic Rx/Tx pair. Microwave detectors are easy
to make: a small loop antenna at the right wavelength (122mm?) for 2.45
GHz with a signal diode in one leg of the loop (don't know if a 1N914 is
fast enough) to rectify the signal and charge a capacitor with enough voltage to fire a small neon tube. The neon will fire every time the cap gets enough voltage.

[MadManMarkAu]

As far as I know, it was not from an industrial unit. I don't think it's a thermal breaker, because I already salvaged them from the unit (about 3 or 4 of them).

If I remember correctly, it was from a National-brand microwave. That's all I really know now, because the junk has since been returned to the tip site. But it did seem to be quite a large unit.

And, I don't have a multimeter or other equipment on hand to explore it