Mystery Object Quiz

[Robert Atkinson 2Participant @robertatkinson2]

A bit ofa brain teaser for you. I just won a “that looks interesting” auction on ebay. It included 3 of these:

It’s made from springy metal probably stainless steel and is about 33cm long.
The listing only showed three diecast boxes marked “strain guage amplifier”. They belong together.
So what are they used for? One other clue, the cardboard box had BNFL written on it.

No prizes…

Robert.

 

[John HaineParticipant @johnhaine32865]

I hope they aren’t too radioactive…

[Robert Atkinson 2Participant @robertatkinson2]

Nothing detected….

It has a potential application in the workshop

[Nigel Graham 2Participant @nigelgraham2]

From the labels alone this former British Nuclear Fuels Limited property would have been used with electrical strain-gauges for measuring very tiny expansions or contractions in the material of items under strain-test. (E.g. the wall of a pressure-vessel).

The strain-gauge transducer itself for which this was the amplifier, may be the resistive form I have briefly used (at work). A long length of resistance-wire alloy, in a back-and-forth arrangement for compactness, is encapsulated within a thin plastic sheet that is adhered to the surface under test. The strain stretches the wire enough for a detectable, proportional change in resistance.

 

On its own that strain-gauge amplifier is about as useful as a chuck with no jaws. You might be able to use the strip as material for something, and I expect you’ll give the diecast boxes a new career!

[peter1972Participant @peter1972]

That’s not a strain gauge amplifier.

At the top of your first photograph inside the ‘jaws’ of the object, are two thin wires visible connecting to some type of sensor attached to the left jaw?

[Speedy Builder5Participant @speedybuilder5]

its for splitting atoms. You pop an atom between the jaws and switch it on ?

(name withheld)

[Robert Atkinson 2Participant @robertatkinson2]

It’s a complete working device not just a bare strain gauge. I didn’t post a picture of the amplifer as it’s just a painted diecast box with a couple of 9 way D connectors/ It has both analog and serial digital outputs.

Well spotted Peter. That is a Pt100 temperature sensor at the tip. However temperature measurement is a secondary function.

Robert.

[peter1972Participant @peter1972]

Is that a ZrCo wire mesh for measurement of helium leakage?

See Fig 2 here: https://www-pub.iaea.org/Mtcd/Meetings/PDFplus/2010/cn180/cn180_papers/ftp_p1-03.pdf

Can’t say I would find it at all useful.

[Robert Atkinson 2Participant @robertatkinson2]

No, not a Helium detector.

Definitely usable in the workshop.

Robert

[Robert Atkinson 2Participant @robertatkinson2]

Another clue.

It’s specification is 1.5 to 5mm, resolution 0.01mm.

Robert.

[David Millar 3Participant @davidmillar3]

Could they be used as an alternative to a DTI?

[Howard LewisParticipant @howardlewis46836]

Some form of strain gauge calibration device?

Howard

[larry phelan 1Participant @larryphelan1]

I think it,s a Wasim.   I dont know what a Wasim is but it looks like one anyway.

Now, how to use it is another question !

[Robert Atkinson 2Participant @robertatkinson2]

David has it.

It’s a gap gauge for measuring the spacing between fuel rods in a nuclear reactor. Deflecting the the spring tips induces stress proportional to the displacement. The temperature is is used for compensation. As the only materials in the reactor are metals and some insulation it not affected by high levels of radiation. They could be used to measure the width along any deep slot or gap. With a spherical adaptor it could check bores. Just needs a 24V supply and a meter on the analog output to make a long reach DTI.
I hate to think what BNFL paid for them but the three probes and interfaces cost me £20 on ebay 🙂 The probes were not pictured in the listing, they were still wrapped up. There was also a bunch of paperwork in the box. This included calibration sheets for the 3 probes, connection information and a description of the serial communication protocol.

Robert.

[Speedy Builder5Participant @speedybuilder5]

Robert – Let us know the next time you use it on a “proper” job.

Bob

[DiogenesParticipant @diogenes]

Looks ideal for touching-off a cutter to establish ‘Z’ height..

 

[PlasmaParticipant @plasma]

Sneaked home from some nuclear site in a lunch box no doubt lol

[Plasma]

On Plasma Said:

Sneaked home from some nuclear site in a lunch box no doubt lol

If it was then I hope it was Monitored

[Robert Atkinson 2Participant @robertatkinson2]

Over 20 years ago I bought a bit of electronic test equipment on ebay from a company in Dorset. Collection only. So I drove over to the address in Winfrith, not thinking anything of it. It was only when I got close that I realised the the company was within the UKAEA site. And I had a Radium luminised aircraft instrument in the back of the van. I could see the radiation detectors at the gate….
So I pulled into the visitors car park and called the seller to ask him to bring the unit out to me. I would have had a lot of explaining to do when I tried to leave if I’d not realised and gone into the site.

Robert.

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