Letter Re: Test Sources for Radiation Meters–The Cesium Source


RE: > I also didn’t buy the use of a smoke detector to test a CDV survey meter so I checked it out. Didn’t show squat since that meter is relatively insensitive.
Oh, I also tried a smoke detector with my Digilert-100 from http://www.seintl.com .
This detector reads Alpha, Beta, Gamma and X-rays. Nada.

BTW, the Digilert has available some neat software that I use to track background radiation on a daily basis.
Normal background here in Colorado is between 20 and 39 counts per minute.
The unit also has an alarm level that can be set to any given level of radiation. I keep mine at 50 Counts per minute. The only time it ever went off was on the interstate while passing one of those semi flatbeds carrying two big concrete cylinders. (Probably a radiation waste transport). needless to say, I made a distinct effort not to pace HIM anymore.
I’ve been using the old yellow CDV radiation detectors and haven’t noticed any deterioration with the chamber.
As a note, the CDV-700 (with the wand, a true geiger counter) also will see background if you cheat. With the probe cover opened (roll it around until the slots are open, but NEVER use it in service with the cover open) , and the adjustment turned up, you will see background radiation. I used the Digilert-100 and adjusted the screw pot on one of the CDV-700’s until it matched the background count on the Digilert-100. Amazingly enough when done, the CDV-700 mostly passed the check using the beta source on the side of the unit. Needle went a little high than it was supposed to, but not much. Maybe I should say it was close enough for Government work.
The German surplus dosimeters from Major Surplus also passed testing at a local metallurgical shop with a source.
All in all, my two cents worth is everybody oughta have some of the above, just like a spare tire in your trunk.
I just hope I never have the occasion to see a reading on the less sensitive survey meters! (Insert wry smile here.)

A thought to keep in mind about battery chargers. I’m sure that a sizeable percentage of readers of this blog have rechargeable batteries and battery chargers. I wonder how many of those battery chargers require AC power (normal house electricity) to work. Keep in mind there are some great DC battery charges out there. Most will power up with 12 Volts DC and charge NiCd, NiMh, Li-ion and Lead Acid batteries from 1.2 volts to 30 volts DC.
Could make the difference sometime. (Hint, keep it in the car and it will even charge your cell phone Li-ion battery with two paper clips and a little ingenuity.

I forgot to mention that I always have that Washington, D.C. status symbol with me–my NukAlert from http://www.ki4u.com
Wouldn’t be without it. Amazing how many “civil servants” (Please note the quote marks) in D. C. have this device. If I was in D.C. very often, I’d probably carry two, just kidding. But seriously, it does provide peace of mind. Best Regards, – The Army Aviator