[ RadSafe ] Low Level Readings using probes

Chris Alston achris1999 at gmail.com
Wed May 16 14:36:38 CDT 2012


It is absolutely *not* worth buying probes for a CDV-700.  It is obsolete,
and is only capable of the most basic measurements.  It is not entirely
clear what sorts of measurements you may need to make with your meter
(basically, doserate vs. countrate), but, in general, to maximize the
utility of the meter, you would want a meter with dead-time correction,
adjustable HV, and at least a readily adjustable discriminator, preferably
an easily adjustable window.

I would call someone like Dwane Stevens at Ludlum Measurements, and discuss
your needs with him.  Caveat emptor, manufacturers are introducing more and
more "smart" instruments, meters and probes both, which are essentially
proprietary to them, and only they can provide service for them.


On Tue, May 15, 2012 at 12:50 PM, Matt Sargent <
m.sargent at buffaloinspection.com> wrote:

> Low Level Readings using probes
> One thing I've read that I am trying to understand, is it sounds like the
> response output is only linear up to a certain point on certain detectors,
> after that readings become non-linear, this leads me into wondering about
> how well various products deal with this, from what I can tell any given
> meter/software solution had best be tied to a specific probe's
> characteristic, not only in the high voltage power supply requirement, but
> also to linearize the respond at various source levels which could
> potentially confront the detector. Is this something worth worrying about?
> I've yet to see any plots of how non-linear the response gets.
> Up to this point in time, I have been comparing relatively small counts,
> if that was all I cared about, why spend a great deal more, get a really
> good detector and hook it up to just about any old meter/power supply and
> take the readings. Kind of what I've been thinking. However, if I want to
> have accurate comparable numbers from higher intensity levels, I have
> better make sure my detector probe model is supported (and it's
> non-linearity corrected) by whatever measurement meter/software solution
> we're using.
> If that makes sense?
> I have an old CDV-700 model meter and I am trying to decide if it is
> worthwhile to get an alpha, beta, gamma probe for it or upgrade completely
> to something new?  I am looking at the RDS-31 with the GMP-11 probe.  As I
> a very familiar with the RDS family I have a bunch of the RDS-30's on the
> Job Site.
> One other question I have pondered is the degrading effect that Radiation
> has on electronics how does the new digital equipment shield itself from
> this?  Not that one is high rate areas all the time but how will they last
> over time?
> Can any one point me to some papers or studies that can possibly give me
> some answers or make some recommendations?
> Kindly,
> Matt Sargent
> Safety Compliance Officer
> [Description: Description: Description: buffaloLogoFinal]
> 8403 Davies Road NW Edmonton, AB T6E 4N3
> Ph: (780) 486 7344 Fx: (780) 486 4685
> www.buffaloinspection.com<http://www.buffaloinspection.com/>
> _______________________________________________
> You are currently subscribed to the RadSafe mailing list
> Before posting a message to RadSafe be sure to have read and understood
> the RadSafe rules. These can be found at:
> http://health.phys.iit.edu/radsaferules.html
> For information on how to subscribe or unsubscribe and other settings
> visit: http://health.phys.iit.edu

More information about the RadSafe mailing list