[ RadSafe ] Background from Static Electricity in Tritium counters

[Richard L. Hess]

Dear Dr. Gaitan,

Years and years ago, a product called the Zerostat was made in 
England. It looks ever so much like a white gun with a large chrome 
trigger. In the front of the gun is a needle and inside is a piezo 
electric crystal of some flavour. You squeeze the trigger and it 
ionizes the air which drains off static.

It was originally designed for helping to clean phono records. I have 
used it for helping with static cling on my wife's dresses.

Although it is still working, it wasn't up to the challenge of a 
large cardboard box filled with foam packing peanuts at 35% RH at 
21C. I ended up using a vacuum cleaner and sacrificing a bag to 
getting all of them out of my room.

Anyway, if you could use something like this to discharge the static 
before the measurement, I wonder if that would help. There is also a 
spray called "Static Guard" that my wife now uses with her clothes. 
She prefers that to me shooting her with invisible ions <smile>. The 
Zerostat stays next near my turntable, although I won't admit to 
restoring discs commercially as I do tapes.

I don't know if these excess ions will affect your measurements in 
other ways, but it's one way of getting rid of small static charges.

Another way -- and I suspect that you don't want any of this loose in 
your facility -- was in the 1960s, you used to be able to purchase 
anti-static brushes that had a block of polonium in them (I hope I 
remembered that correctly--it's been close to 40 years since I saw 
one of those in action). These were for cleaning negatives in 
photographic darkrooms.

Finally, the electronics manufacturing and repair industries have a 
wide variety of tools and protocols for draining static charges as 
many semiconductor devices are sensitive to static discharge. There 
are mats, wrist straps, and I don't know what else, as I've never 
actually had to spec one of these workstations other than 
generically. (i.e. provide industry-standard static-safe circuit 
board rework station).

Cheers and best of the season to everyone!

Richard

At 04:30 PM 12/23/2005, Felipe Gaitan wrote:
>Dear Radsafers,
>
>Does any body have a suggestion for minimizing the effects of static 
>electricity in tritium counters?
>
>I'm using glass vials.  The effect has become obvious since the 
>weather turned cold and subsequently the air became drier.  I can 
>measure the background slowing decreasing over a couple of days as 
>long as I leave the vial in the counter.  As soon as I take it out 
>and then put it back, the background counts jump up again, sometimes 
>by as much as a factor of two.  It appears to affect some vials and not others.

Richard L. Hess                   richard at richardhess.com
Aurora, Ontario, Canada       http://www.richardhess.com/
Detailed contact information: http://www.richardhess.com/tape/contact.htm