What is this?
This is not a quiz or a puzzle. I want to know what it is.
All I know is that it is something used in a biology lab. This thing was found loose inside a piece of used equipment.
It’s got 4 wires coming out – looks like a standard telephone cable. When I measure, I see 2218 ohms between black and red, 2267 ohms between black and green, and 4470 ohms between red and green. Yellow seems to be disconnected (open circuit).
The knurled ring thing (above) tightens down a rubber stopper – looks like it was meant to go into some kind of bottle or flask. The stopper isn’t airtight tho (it’s not completely sealed against the metal tube).
Below are oblique, end-on, and side views of the “business end”. It appears to have two little glass bulbs at the end, each with something black or dark grey inside. (The little white circles in the photos are just reflections of the ring light on my microscope.)
What is it??
Update, October 27 2013:
Looks like Bob was right.
When I wave a hot air gun at it (set at 100 C), the resistance between red and black instantly drops to about 1.4 k ohms, red to green goes to about 3 k ohms, and green to black goes down to 600 ohms or so. It definitely seems to be a temperature probe.
I suspect the two bulbs are arranged red – (bulb) – black – (bulb) – green, and that the two bulbs’ different responses somehow contribute to stability and/or linearization of the output. Probably it wouldn’t be too hard to calibrate it, but for now it goes on the shelf. At least I know what it’s for (even if I still don’t know who made it).
The exterior looks like a temperature probe. I have PT100 temperature probes I used for my sous vide, but they have three wires and there are no bulbs inside.
Try putting it in hot water and see if the resistances change.
Looks like you were right. I updated the post.