Hi all,
this is not a Scintillation detector, but I wanted to let you know that I (so far) succesfully repaired two BZ 100 XEP that is inside a contamination monitor from german brand Berthold called LB1210b
The measuring chamber is nearly 10x10cm and detects betas and of course gamma and x-rays. The used foil is 5mg/cm² so nearly 0,01mm thick titanium foil.
The meter is reacting very fast and is my faforite in detecting radiation quickly. Once measunring in the wilderness it can happen that a stone penetrates the sensitive foil and it breakes.
So it was time to fix that.
Things you need for repair:
1. Argon gasbottle 1liter
2. Argon/CO2 gasbottle 1 liter
3. hoses 6mm aquarium silicone hoses
4. valves for 6mm hoses
5. threeway adapters for 6mm hoses
6. 3mm copper pipe
7. 6mm wire end splices
8. Butan/Propan torch
9. some solder (i used the leaded one)
10. 50mm syringe
11. new titanium foil 0,01mm x 120 x 120mm
12. adhesive tape (clear) if you just repair the foil
13. Aceton
14. nito-cellulose thinner for cleaning the hard stuff
15. some kind of eleastic 2K glue (not that easy to be honest)
Procedure:
theory:
it should be possible to repair the foil by either use clear adhesive tape or to use new foil like described.
Demounting the complete measuring chamber, cleaning the edges of the chamber and the protection grid and as well the foil if reused.
gluing the foil onto the chamber and filling it with a gas. It was not that easy to find which gases are normally used.
The original BZ 100 XEP uses Xenon. This is quite too expensive now so i looked around to find other mixtures of gases.
What I found:
Propane/Butane for flushing chambers
Neon or other halogen
Argon/CO2 80/20%
Argon Methan 90/10%
As Ar/Methane was quite difficult to get I went for the cheap Ar/Co² that costs here around 32 Euro / liter
Once the gas is inside, suck a little out of the chamber to reach a plausible negative pressure, pinching of fthe copperhose, solder it and we would have a measuring chamber ready...
That was theory.
Berthold LB1210 with BZ 100 XEP measuring chamber (GEIGERCOUNTER)
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keuleeule
- Posts: 76
- Joined: 31 Oct 2016, 09:09
Berthold LB1210 with BZ 100 XEP measuring chamber (GEIGERCOUNTER)
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keuleeule
- Posts: 76
- Joined: 31 Oct 2016, 09:09
Re: Berthold LB1210 with BZ 100 XEP measuring chamber (GEIGERCOUNTER)
Now the procedure I did it:
first after cleaning the chamber edges, the foil and the protection grid (which was not that easy as bad sticking stuff hold everything is place)
I wonder how I should get gas inside the chamber with only one copper pipe access. An idea was to heat everything up to high temperature, connect the gasbottle and during cooling down the gas would suck into the chamber... but all the normal air, where should it go?
So my idea was to drill a second hole into the chamber so that a second access (pump port) is ready. When flushing argon through the chamber and turning the chamber in all directions it should hopefully help to clean the chamber from O² and normal air.
finding a good spot for the second pump port and adjusting the 3mm copperhose. I wanted to use an area that was far away from the original pump port and on an edge to get maximum affect of flushing new gas into it.
The copperpipe was too long, so I had to shorten it a bit.
finally the soldered second pump port in the lower right.
So now I tried at first to use a kind of rubber silicone to glue the foil onto the chamber but that was not successful, so I used 2K epoxy glue.
wait until the 5 minutes epoxy glue is ready. loaded with lead 3,2kg - waited several hours.
first after cleaning the chamber edges, the foil and the protection grid (which was not that easy as bad sticking stuff hold everything is place)
I wonder how I should get gas inside the chamber with only one copper pipe access. An idea was to heat everything up to high temperature, connect the gasbottle and during cooling down the gas would suck into the chamber... but all the normal air, where should it go?
So my idea was to drill a second hole into the chamber so that a second access (pump port) is ready. When flushing argon through the chamber and turning the chamber in all directions it should hopefully help to clean the chamber from O² and normal air.
finding a good spot for the second pump port and adjusting the 3mm copperhose. I wanted to use an area that was far away from the original pump port and on an edge to get maximum affect of flushing new gas into it.
The copperpipe was too long, so I had to shorten it a bit.
finally the soldered second pump port in the lower right.
So now I tried at first to use a kind of rubber silicone to glue the foil onto the chamber but that was not successful, so I used 2K epoxy glue.
wait until the 5 minutes epoxy glue is ready. loaded with lead 3,2kg - waited several hours.
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keuleeule
- Posts: 76
- Joined: 31 Oct 2016, 09:09
Re: Berthold LB1210 with BZ 100 XEP measuring chamber (GEIGERCOUNTER)
The filling process
How to be sure that no normal air is inside your arrangement? You need to flush the complete system.
How much gas is needed? I have no idea, so I hooked up two bottles of gas, one was pure argon (hardware store quality) as I already had one bottle the other the mixture of Ar/CO² 80/20%
I also bought a second pure Ar bottle.
How long should I flush the system? I have no idea, so I hoped both bottles were enough. Now I can say it should work with one bottle of Ar/CO² already... But I was unsure and afraid to change a bottle inbetween, so I decided to hook up both in the chain.
The 6mm aquarium silicone hoses easily attached to Ag/CO² and Ar bottle, even the syringe fitted perfectly with the hose. Only the chamber copperhose was too small, so I soldered a 6mm end splice or wire termination or wire end sleeve (had to check the english name for it)
to make it compatible.
So here the complete arrangement:
With this arrangement I was able to use both gasbottles at the same time, or only one, to close the bottles and suck negative pressure with the syringe.
So my procedure was now flushing the system, means to disconnec the Ar/CO² bottle to fill the hose to that bottle. Open the syringe to let Argon flow though it. Open all valves. Then step by step closing valves connecting Ar/Co²bottle, close the syringe, close valves.
Then flushing the system for ten minutes pure Argon.
After 2,5m I tilted the chamber to one side
after 5 m to the other side
after 7,5m outlet to the top.
No idea if that is necessary... Argon is heavier than air, so my idea was to fill the complete chamber with Argon and if the lower part already have Argon, it just fill up to the egde and everything is filled up nicely.
Then the second gasbotlle was activated, followed by closing the pure Argon. Now Argon/CO² is flushing through the system. I did that 5 minutes. Turning the chamber in my hand in all directions.
One problem was that pinching off the copperpipe (the pump port) would result in an overpressure in the measuring chamber, and the foil is thinn! So it was not that easy to handle. I decided to close the valve to the chamber, pinch off the second pump port, solder it imideately. Close the gas bottle. open the valve to the syringe and suck 30mm of volume into the syringe to have a negative pressure in the chamber. Here I checked if the "vacuum" is consistent. As it was, I pinched off the original pump port and imideately solder it.
How to be sure that no normal air is inside your arrangement? You need to flush the complete system.
How much gas is needed? I have no idea, so I hooked up two bottles of gas, one was pure argon (hardware store quality) as I already had one bottle the other the mixture of Ar/CO² 80/20%
I also bought a second pure Ar bottle.
How long should I flush the system? I have no idea, so I hoped both bottles were enough. Now I can say it should work with one bottle of Ar/CO² already... But I was unsure and afraid to change a bottle inbetween, so I decided to hook up both in the chain.
The 6mm aquarium silicone hoses easily attached to Ag/CO² and Ar bottle, even the syringe fitted perfectly with the hose. Only the chamber copperhose was too small, so I soldered a 6mm end splice or wire termination or wire end sleeve (had to check the english name for it)
to make it compatible.
So here the complete arrangement:
With this arrangement I was able to use both gasbottles at the same time, or only one, to close the bottles and suck negative pressure with the syringe.
So my procedure was now flushing the system, means to disconnec the Ar/CO² bottle to fill the hose to that bottle. Open the syringe to let Argon flow though it. Open all valves. Then step by step closing valves connecting Ar/Co²bottle, close the syringe, close valves.
Then flushing the system for ten minutes pure Argon.
After 2,5m I tilted the chamber to one side
after 5 m to the other side
after 7,5m outlet to the top.
No idea if that is necessary... Argon is heavier than air, so my idea was to fill the complete chamber with Argon and if the lower part already have Argon, it just fill up to the egde and everything is filled up nicely.
Then the second gasbotlle was activated, followed by closing the pure Argon. Now Argon/CO² is flushing through the system. I did that 5 minutes. Turning the chamber in my hand in all directions.
One problem was that pinching off the copperpipe (the pump port) would result in an overpressure in the measuring chamber, and the foil is thinn! So it was not that easy to handle. I decided to close the valve to the chamber, pinch off the second pump port, solder it imideately. Close the gas bottle. open the valve to the syringe and suck 30mm of volume into the syringe to have a negative pressure in the chamber. Here I checked if the "vacuum" is consistent. As it was, I pinched off the original pump port and imideately solder it.
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keuleeule
- Posts: 76
- Joined: 31 Oct 2016, 09:09
Re: Berthold LB1210 with BZ 100 XEP measuring chamber (GEIGERCOUNTER)
Here the over pressure during flushing the chamber:
Both pump ports soldered
underpressure - the chamber is ready
Both pump ports soldered
underpressure - the chamber is ready
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keuleeule
- Posts: 76
- Joined: 31 Oct 2016, 09:09
Re: Berthold LB1210 with BZ 100 XEP measuring chamber (GEIGERCOUNTER)
Testing the chambers
Background
the meter with the sticker is the Ar/CO² refurbished one
With Th prism
Chamber is working since 27 hours
Maybe to add: one foil was repaired with clear adhesive tape, the other one was undestroyed but pealed off on one edge. Both working so far.
I hope that the mini vacuum I used will hold. That depends on the adhesive tape, the glue and maybe much more.
But so far its a success !
Repairing this chamber at manufacturer is not possible anymore as they do not have Xenon anymore and a replacement is nearly 700 Euro.
I described more detailed in german forum: https://www.geigerzaehlerforum.de/index ... 380.0.html and had help of a guy who already repaired a chamber https://www.mikrocontroller.net/topic/365829
thanks, Kolja
Background
the meter with the sticker is the Ar/CO² refurbished one
With Th prism
Chamber is working since 27 hours
Maybe to add: one foil was repaired with clear adhesive tape, the other one was undestroyed but pealed off on one edge. Both working so far.
I hope that the mini vacuum I used will hold. That depends on the adhesive tape, the glue and maybe much more.
But so far its a success !
Repairing this chamber at manufacturer is not possible anymore as they do not have Xenon anymore and a replacement is nearly 700 Euro.
I described more detailed in german forum: https://www.geigerzaehlerforum.de/index ... 380.0.html and had help of a guy who already repaired a chamber https://www.mikrocontroller.net/topic/365829
thanks, Kolja
You do not have the required permissions to view the files attached to this post.
-
keuleeule
- Posts: 76
- Joined: 31 Oct 2016, 09:09
Re: Berthold LB1210 with BZ 100 XEP measuring chamber (GEIGERCOUNTER)
Some mistakes in my report... mm and ml need to be checked ! Bad auto correction...
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Sesselmann
- Posts: 1398
- Joined: 27 Apr 2015, 11:40
Re: Berthold LB1210 with BZ 100 XEP measuring chamber (GEIGERCOUNTER)
This is just a reminder how it is worth picking up cheap non working instruments if you are prepared to attempt a repair. Often it is much simpler than you think. I picked up a non working Fluke 451 ion chamber on ebay and expected a complicated repair and within 5 minutes of probing I discovered the lead to the 9V battery tab was broken. If it turns out to be an impossible repair, at least you have a nice door handle 😂
Steven
Steven
