Mystery electronics parts...

[Alondro]

I have about a dozen of these odd little parts. What are they and what sort of plating is over those end electrodes, does anyone know?

I say 'plating', but it looks like some of them have solid single-metal composition of those 'electrodes'. And it's a soft silvery metal. It does tend to boost my hopes, as those electrodes are pretty large, meaning a LOT of PM for each piece.

 

[Martijn]

Those top two look like fuses.
Can you take a picture of the other side of the electrodes/sensors?

 

[Christian333]

I have about a dozen of these odd little parts. What are they and what sort of plating is over those end electrodes, does anyone know?

I say 'plating', but it looks like some of them have solid single-metal composition of those 'electrodes'. And it's a soft silvery metal. It does tend to boost my hopes, as those electrodes are pretty large, meaning a LOT of PM for each piece.

View attachment 58004View attachment 58005

Gas discharge tubes/spark arrestors. One member in a Facebook group recovered platinum and palladium from some, they were old 1970s military. Yours do not mention precious metals on the data sheet.

Janie

 

[Alondro]

Gas discharge tubes/spark arrestors. One member in a Facebook group recovered platinum and palladium from some, they were old 1970s military. Yours do not mention precious metals on the data sheet.

Janie

They do have different metal inside them, the plating in those two I had left intact until I got a picture looks steely, not silvery like the others.

I suppose I'll just have to pop them all open and see that they look like. It only takes a second apiece to break the ceramic, so it's worth it to take a look.

 

[KalleMP]

Gas discharge tubes/spark gaps may be placed into two primary categories (and dozens of sub categories).
.
Those that are for sporadic protection use and those that are in frequent discharge use.
The first type is made as cheap as possible because they used to have two at each end of every telecommunications line to shunt lightning induced voltage spikes to ground to protect more sensitive equipment. They would be able to handle dozens to hundreds of flashovers and the contact metal would have been as cheap as possible. A series resistance or line inductance would have prevented destructive currents and they can work for decades in regular areas and many years in high lightning regions with aerial cables. Yours look like these.
.
The second type would be used to regulate peak voltage or provide a fast turn on characteristic for an ignition pulse or many other circuit functions. They may also provide the same over voltage protection from repeated/regular equipment induced voltage spikes that could have resulted in thousands or millions of arcing events. These devices are usually intended to last a long time, even the life of the equipment and are made of much tougher stuff usually. They may have interesting electrode metals and can take on many interesting shapes with 3 or even more electrodes that are usually not the same shape as the simple ceramic over voltage protection but may be. Often made of glass but do not have to be.
.
The last point to note is that rarely/occasionally these devices may contain miniscule amounts of radioactive substances, this was often a dot of radium paint on the inside of the ceramic or glass tube. I suppose one or both electrodes could have a trace amount of a radioactive metal like Americium alloyed in the material itself. The reason for the radioactive material was to pre-ionise the usually noble gas inside so that the tube would trigger at a more repeatable or lower voltage. These materials are generally only harmful if you ingest or inhale dust from them. I have broken open dozens of these over the years but for this reason I would not make a career of trying to recycle them unless checking first for radiation with a SUITABLE alpha ray sensitive detector.

 

[eaglekeeper]

Gas discharge tubes/spark gaps may be placed into two primary categories (and dozens of sub categories).
.
Those that are for sporadic protection use and those that are in frequent discharge use.
The first type is made as cheap as possible because they used to have two at each end of every telecommunications line to shunt lightning induced voltage spikes to ground to protect more sensitive equipment. They would be able to handle dozens to hundreds of flashovers and the contact metal would have been as cheap as possible. A series resistance or line inductance would have prevented destructive currents and they can work for decades in regular areas and many years in high lightning regions with aerial cables. Yours look like these.
.
The second type would be used to regulate peak voltage or provide a fast turn on characteristic for an ignition pulse or many other circuit functions. They may also provide the same over voltage protection from repeated/regular equipment induced voltage spikes that could have resulted in thousands or millions of arcing events. These devices are usually intended to last a long time, even the life of the equipment and are made of much tougher stuff usually. They may have interesting electrode metals and can take on many interesting shapes with 3 or even more electrodes that are usually not the same shape as the simple ceramic over voltage protection but may be. Often made of glass but do not have to be.
.
The last point to note is that rarely/occasionally these devices may contain miniscule amounts of radioactive substances, this was often a dot of radium paint on the inside of the ceramic or glass tube. I suppose one or both electrodes could have a trace amount of a radioactive metal like Americium alloyed in the material itself. The reason for the radioactive material was to pre-ionise the usually noble gas inside so that the tube would trigger at a more repeatable or lower voltage. These materials are generally only harmful if you ingest or inhale dust from them. I have broken open dozens of these over the years but for this reason I would not make a career of trying to recycle them unless checking first for radiation with a SUITABLE alpha ray sensitive detector.

Excellent explanation, thanks.

I guess I'll be going through my "bucket of unknowns" and picking those out for disposal.

 

[Alondro]

Gas discharge tubes/spark gaps may be placed into two primary categories (and dozens of sub categories).
.
Those that are for sporadic protection use and those that are in frequent discharge use.
The first type is made as cheap as possible because they used to have two at each end of every telecommunications line to shunt lightning induced voltage spikes to ground to protect more sensitive equipment. They would be able to handle dozens to hundreds of flashovers and the contact metal would have been as cheap as possible. A series resistance or line inductance would have prevented destructive currents and they can work for decades in regular areas and many years in high lightning regions with aerial cables. Yours look like these.
.
The second type would be used to regulate peak voltage or provide a fast turn on characteristic for an ignition pulse or many other circuit functions. They may also provide the same over voltage protection from repeated/regular equipment induced voltage spikes that could have resulted in thousands or millions of arcing events. These devices are usually intended to last a long time, even the life of the equipment and are made of much tougher stuff usually. They may have interesting electrode metals and can take on many interesting shapes with 3 or even more electrodes that are usually not the same shape as the simple ceramic over voltage protection but may be. Often made of glass but do not have to be.
.
The last point to note is that rarely/occasionally these devices may contain miniscule amounts of radioactive substances, this was often a dot of radium paint on the inside of the ceramic or glass tube. I suppose one or both electrodes could have a trace amount of a radioactive metal like Americium alloyed in the material itself. The reason for the radioactive material was to pre-ionise the usually noble gas inside so that the tube would trigger at a more repeatable or lower voltage. These materials are generally only harmful if you ingest or inhale dust from them. I have broken open dozens of these over the years but for this reason I would not make a career of trying to recycle them unless checking first for radiation with a SUITABLE alpha ray sensitive detector.

I just so happen to have a scintillation counter! It detected a radioactive rabbit once! Heh, a little pale yellow ceramic bunny with uranium glaze.

(One test later) No trace of radiation from those I've opened.