RE: Survey Inst. OPINION

[VERNIG.PETER@FORUM.VA.GOV]

{Original Msg: 'Survey inst.' from <radsafe@romulus.ehs.uiuc.edu>
{
{Thought I would elict some comments on features of portable
{survey instruments, likes, dislikes, wishes, etc.
{
{While I like and appreciate the added 'power' of the new digital
{based instruments I get frustrated at the non-intuitive controls. 
{And for our researchers (non-expert users) I really need simple
{(i.e., old fashioned) instruments. [Why cannot sticker notes be
{affixed with help info for the more obscure operating features?]
{
{I am very attracted to the Victoreen 450's, but with the
{autoranging design there is no way to simply look at the
{instrument to identify its upper range.  We have some that go to
{50 R/h, and others that go to 500 R/h.  [How about a label?]
{Similarly, the Eberline ASP-1 meter displays its unhappiness when
{overranged by irratic meter movement [how about a warning
{label?].
{
{I also dearly love the check feature on the Eberline ASP-1 where
{it displays a result reflective of all the cal settings.  It is a
{great Q.A. check to see that nothing has changed (but it cannot
{check the detector).
{
{On the subject of Q.A. checks, why do we not have more in these
{modern instruments?  Like...
{ -next due cal date (in an Eberline instrument)
{ -most recent date any changes were made in operating settings
{ -selective display of important settings (in the field, not on
{the computer in your cal lab).
{ -is it an unreachable dream that an instrument will be able to
{self diagnose well enough that calibration and performance checks
{will not be needed?
{
{We still need simple instruments.  Victoreen stopped making the
{rugged Model 400 (which had some nice features like an off scale
{alarm on the selected range) but the replacement does not do the
{same job.  The basic Tech Associate TSM (pancake tube, analog
{ratemeter, inexpensive) and similar products (Ludlum, Johnson)
{still have a place on my shelf (despite liking the new, high-tech
{digital items).
{
{While it is tough to come up with a new detector (I would guess
{that Bicron's energy compensated plastic scintillator is the most
{recent in a portable survey instrument) the new electronic
{technolgy lets more be done.  The Eberline sealed alpha/beta
{probe and the Victoreen ion chamber technology are good examples.
{It will be nice when the LET spectroscopy systems achieve an
{adequate dose rate and energy threshold sensitivity.
{More?
{
{Reliability, performance to spec's, etc is another topic.
{Interesting times for portable instruments.
{
{Obviously, my opinion only.
{Food for thought on a slow spring day.
{slaback@MICF.NIST.gov
 
 
First I am sending this message using the A-nswer function which, I think
should only send it to whoever I put in the address box which will be the
initiator only, Les Slaback.  If you are not Les and get this prior to
6:00pm you're local time please shoot me a brief message @ vernig.peter*
forum.va.gov.
 
I am basically only familiar with Bicron, Ludlum, Mini Inst.; and Tchnical
Associates for the past few years.  These are only my opinions and do
not represent anybody elses, especially my employer etc.
 
Things I like about Ludlums,
|TAB|Easy battery change, range adjusting pot's accessible through the
case, rugged, inexpensive, simple.  I always recommend that researchers
get instruments that read out in only cpm for GM count rate style inst.
I've beat my head against a wall too long to think a lab tech is likely
to understand MEASUREMENT of dose rate with a GM system.
 
Things I like about Bicrons;
|TAB|HV Check and or readout.
|TAB|On board spare battery [I like this a WHOLE LOT! it has saved me
|TAB||TAB||TAB||TAB|a lot of aggrivation repeatedly]
 
Things I like about Tech. Ass.  They have some units that have an on
board pancake and external scint probe which can be real convenient
for someone inspecting a life science lab with a variety of isotopes.
 
Other features.  I like to see the adjustment potentiometers all together
and scale & hv identification on the circuit board if they are not 
accessible through the case as the Ludlums are.  I also like to see brief
calibration/adjustment instructions on a label inside the case.  As you
might guess, I calibrate these things.
 
BTW  If you noticed I did not list things about the Mini Instruments, there
are things I don't like, hard wired probes, log scale, count/sec readout
but the ones here have been fairly robust and have not required adjustment
which is good because it's a real bugger trying to figure out what to
adjust & how from the manuals.
 
Peter G. Vernig, VA Medical Center, vernig.peter@forum.va.gov
 
 
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VA Medical Center, 1055 Clermont St. MS 115 - DISCLAIMER
Denver, CO 80220; 303-399-8020 x2447 FAX 393-4656 Opinions = Mine
FAX 303-393-4656, vernig.peter@forum.va.gov Opinions =/ VA or USA
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