I purchased a used oscilloscope. Among the accessories is this block. Does anyone recognize it or what it may be for? It's a small metal case with a BNC connector on the end. One one of the sides is a plate with a window. That plate has 4 screws. On the backside of the block is 2 threaded holes. With that plate removed, it looks like there's really nothing much in there except 2 loose wires that aren't connected to anything except the BNC connector. However closer examination shows that there are 2 stubs stubs on the plate with a black part cemented onto it. It appears that the solder connections broke loose. Also those 2 metal posts appear to be the where the 2 threaded holes are in the back side of the metal box. I'm presuming that the black raised pad is some kind of sensor? If anyone recognizes this, please share what it is.

 

Banana to bnc adapter

 

Interesting guess, but the 2 holes are far too small to be for banana jacks. They are threaded and appears to be intended for M2 or M3 screws. I also tested them electrically and they are shorted to each other and to the case.

 

Spark gap?
What is the resistance between the two terminals of that disconnected black thing?
Is the 'window' mica sheet?

 

upon closer look it is clear that the "bananas" are connected to the casing, they are just GND connections. the business part of the unit is the device in the window. likely a sensor of some sort. could be many things (thermopile power detector, piezo element, ...)

 

It might have nothing to do with the oscilloscope purchase.
It looks like an alpha particle detector.
The two screw holes are mounting holes.

Edit: PN diode gamma ray detector,

 

It is made by Tektronix evidentally, a email to them may clear it up!!

"For more than 70 years, Keithley, a Tektronix company, has been designing, manufacturing, and marketing advanced electrical test instruments and systems for the specialized needs of electronics manufacturers in high-performance production testing, process monitoring, product development, and research."

 

Hello,

It could be some kind of test load.
The wires in the box do not show the connections, it is to dark in the box.

Bertus

 

hi @bertus.

Lightening the shot shows the wires go to the Black pad? or did before the wires were cropped off ????
E

 

Spark gap?
What is the resistance between the two terminals of that disconnected black thing?
Is the 'window' mica sheet?

The window material is conductive so it is not mica, it appears to be aluminum foil. However, I tested it against the case and there is no continuity between the case and that window film.

The "pad" has gold colored pins. Maybe it's brass but there is zero tarnish on it which I would expect to have some with brass. It is not copper, as copper is more reddish. They are bright yellow. Resistance between the 2 pins is 227k, but it is polarized, as resistance can only be measured in one direction. OL in the other direction. Switching to capacitance, I measure no significant capacitance. Measured with diode setting yields OL in one direction, and 0.525v in the opposite direction.

Here is a couple of better views of the pad.

 

did you try connecting it to oscilloscope and see what it responds to? movement, sound, light, temperature, vibrations...

 

The "pad" has gold colored pins.

Gold-plated pins are quite common with high quality components.
From your measurements perhaps the mystery device linking them is a photo-diode; hence the window.

 

Gold-plated pins are quite common with high quality components.
From your measurements perhaps the mystery device linking them is a photo-diode; hence the window.

I can't imagine how a photo-diode would function, that window is covered in foil and that pad certainly doesn't even look like any kind of a diode I ever saw. That the wires that connect to the pad both broke off makes me suspicious that it's maybe from vibration, so it could be a vibration sensor seeing how it's encased in some kind of mastic. Or perhaps it's a radiation detector (medical device?). As the scope came in a portable tektronix branded carry bag, I'm guessing the scope and accessories were part of a field techs tool set. I'm considering to just remove the guts and repurpose the box. If it's some kind of exotic sensor, I'd never use it anyways but wanted to hold off in case this device has some useful purpose that would be wasteful to gut.

 

It is a PN photo-diode. It is covered with aluminum foil on the front and black sealant on the back to block visible light.
It is used to detect x-ray and gamma-ray radiation.

 

Thanks everyone. I think I'm gonna move forward with repurposing that box, whatever that sensor is for, is clearly nothing I would ever have a need for, and I think I already have something in mind for it.