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Reference, Questions and Help => Nuke Q&A => Instrument Q&A => Topic started by: Captain_M on Oct 16, 2017, 12:18

Title: Best Instrument Type for Dose In Tissue Measurement
Post by: Captain_M on Oct 16, 2017, 12:18
Greetings! Some of my question seems to have been covered a little bit in other threads, however I would like get a little more specific if anyone is inclined to answer.


I am looking for a complement of relatively simple and rugged instruments that would be "best" for the at-home nuclear hobbyist to be used in case of a dirty bomb attack, nuclear detonation from a rogue state and the resulting fallout, or perhaps some other nuclear disaster.


What I already have on hand are two energy compensated geiger-mueller type meters: one CDV-700 (0.1mR/hr to 50mR/hr), and one CDV-700 with an EON extended range kit (1mR/hr to 500mR/hr).


I would like something more modern that'd measure higher, as "emergency" radiation levels could potentially reach into the hundreds of Roentgens/Rads/Rems per hour. Obviously one would not last long in these conditions, but the aim is to recognize the threat level and whether there is time to scramble supplies or it's a matter of drive on the shoulder like a madman or get cooked to death.


As far as I know, the other two other types of instruments beyond energy compensated GM's are...the ion chamber and it's later cousin the solid-state diode. To be truthful, I'm clueless as to what the pro's and con's of each are. The only significant things I notice are that diode-type detectors are much smaller in size, and have a *far* wider detection range (often up to ridiculously high thresholds like 9.99Sv/hr).


So far, the instruments I've taken notice of are the: Ludlum Model 25 and 9-3/9-4, Eberline RO-2A, Mirion DMC3000, GammaRAE II R, Canberra AN/UDR 14 & RGU-100, and the various Polimasters which seem to be damn expensive. What are you opinions on ion chambers vs diodes, and/or suggestions on specific instruments. Can any of them include beta emissions and give accurate dose-rates (not even sure if this is possible)?


Thank you in advance for any help offered  :)
Title: Re: Best Instrument Type for Dose In Tissue Measurement
Post by: Rennhack on Oct 16, 2017, 01:31
I favor the Eberline RO-2A. There is one on ebay for $163 (shipping included), which is a steal. http://www.ebay.com/itm/282692443646 (http://www.ebay.com/itm/282692443646)

  ...but... I have to say, you'll never see dose rates like that, ever. 
Title: Re: Best Instrument Type for Dose In Tissue Measurement
Post by: SloGlo on Oct 16, 2017, 08:01
ion chamber vs diode detector... moor of a personal choice accept four won issue, that of the ion detector bean moor susceptible to atmospheric error. ion chambers are typically atmospheric ventilated wyle diode detectors are usually moor sealed. the atmosphere intrusion into the housing may cause errant readings, on the high side of the scale, witch can cause problems when calculating beta dose rates.
any meter inn witch they're is the capability of a net difference between shielded and unshielded detector measurement is able two yield a beta reading. the problem yule run up against is ascertaining the nuclides yew are measuring. their will bee a knead fore you to determine a surrogate isotope for calibration purposes and this, by itself, will inject uncertainty inn two the calculated dose rates you will have.
Title: Re: Best Instrument Type for Dose In Tissue Measurement
Post by: Chimera on Oct 17, 2017, 07:58
First, determine what your isotopes of interest are.  Then look at the energies involved.  Follow up by reading the various tech manuals to determine their energy responses are.  Now you're in a better position to decide which instruments and/or type of instruments you should be looking at.  This is not a "one size fits all" sort of decision.
Title: Re: Best Instrument Type for Dose In Tissue Measurement
Post by: Atombob on Oct 22, 2017, 03:41
Heck, I have a model 9 and 19 and almost any other instrument you want, 2929, 2360,2221,2350 and countless detectors,43-5,44-9, 43-89,43-93. PM me for a price list. Loads of PPE too, tyvek, respirators, filters. Air samplers, gooseneck and lapel.
Title: Re: Best Instrument Type for Dose In Tissue Measurement
Post by: roosterfitz on Oct 23, 2017, 10:24
My friend...the DMC-3000 is an electronic dosimeter and requires a reader and software to be usable. Visit Mirion.com to view your options. Unfortunately, most Civil Defense Ion Chambers are junk because the MOSFET transistor in the chamber has failed decades ago. GM tube or Scintillation are probably your best bet for your "dooms day' fears.