[Phys-L] Re: Survey Meters

[betwys1 at SBCGLOBAL.NET (Brian Whatcott)]

Thanks for the check on unit comparisons.
In browsing for meter schematics, I noticed that an iodide scintillator
  into a PMT seems to be the preferred way of achieving a sensitive detector.
And I was piqued to notice a nuclear spectrum analyzer. Not quite sure of its
operational modus: pulse height binning?

Brian W

At 12:30 PM 10/17/2005, you wrote:
> If FS (Plessey) most sensitive scale is one cGy/hr then my calc. result
> is the old analog would be 500 times more sensitive.  Like photometry a
> proliferation of unites makes conversion difficult.
>
> cGy  ~= cSv   one Sv = 100 rem  [is r on meter rem or rads?]
>
>
> note air dose ~= 0.7 tissue.
>
> so (if no error) no surprise.
>
> bc
>
>
> Brian Whatcott wrote:
> > Remembering that several years ago, I sampled the decay of
> > radio active dist wiped from the terminal screen
> >   (a thread of Luwik's as I recall) I bought a Plessey PDRM 82
> > survey meter as a replacement for the Victoreen OCD: CDV-700
> >
> > The Victoreen was a yellow tin box with an analog meter,
> > an earphone and a tube on a lead. It had a check source stuck
> >   on the side of the can.
> > The Plessey is an orange high impact plastic case with a
> > digital display.
> > The Victoreen was scaled 0.5mr/hr and 300 counts/min
> > with a X100 X10 X1 sensitivity switch.
> >
> > The Plessey scale is marked cGy/h (IN AIR) - and it turns out,
> > the sensitivity is way lower than the Victoreen, so I don't get
> >   a reading from  screen dust. Pity - it looks SO cool!


Brian Whatcott    Altus OK    Eureka!