RE: X-Ray QC equipment.

["Tonry, Louie L MAJ EAMC" <Louie.Tonry@se.amedd.army.mil>]

Mike;

I've used Keithley, Nero, MDH (RADCAL), and others.  Currently we are using
Nero mAx 8000.  It seems to be very good.  Being in the military I've had to
use what was given to me for surveys, thus the wide exposure to various
types of equipment.  With each system, there are strengths and weaknesses.
The MDH (9010) for example evaluates exposure duration from the kV waveform.
This is OK for regular x-ray systems but is frequently a problem for dental
systems.  

Since dental systems often use a preheat, x-rays are produced prior to the
actual activation of the timer circuit.  This can cause the surveyor to
falsely report errors in timer accuracy.

Last time I used the Keithley, it was quite good.  One of the problems I had
with it was it used its own software.  I prefer a system that uses excel (or
equivalent) so I can see the formulas used for calculations and modify them
if necessary.  Further, we have added other sheets in the survey notebook
that include results for the film tests so that when the spreadsheet is
printed, we get the complete data set for the system.  By now, Keithley may
be using excel.

I am kind of partial to the Nero.  The recent upgrade to Nero mAx has proven
to be quite good.  It is available (complete) for a reasonable price.  With
a laptop computer, it runs around 12K.  The software controls for the
hardware allow you to change settings remotely.

Probably the greatest problem I have with the current survey equipment vs. a
good ol' MDH and Wisconsin test cassette, is that you have to be very
careful not to overheat the x-ray tube.  With the new stuff, shots can be
taken, measured, and recorded well outside of the recommended tube rating!

-----Original Message-----
From: Michael Williamson [mailto:m.williamson@mailbox.uq.edu.au]
Sent: Wednesday, March 15, 2000 7:38 PM
To: Tonry, Louie L MAJ EAMC
Subject: Re: X-Ray QC equipment.


on 15/3/00 11:20 PM, Tonry, Louie L MAJ EAMC at
Louie.Tonry@se.amedd.army.mil wrote:

> Mike;
> 
> I do a lot of x-ray evaluations and measurements.  I also like equipment.
I
> can provide you as much and as detailed information as you want regarding
QC
> testing equipment.
> 
> If you drop me a note and tell me exactly what applications you have and
> what you want to know, I'd be happy to coorespond.
> 

Thanks Louie, 

we have a lot of dental units and some veterinary machines (i.e.
conventional fixed medical and mobiles - no CDs as far as I know).  We have
to perform certain tests on these types of X-ray equipment every 3 years -
In case you're wondering why we haven't been doing this before, the
legislation requiring it has just been introduced.

Don't go to too much trouble over this as I have access to local medical
physicists for advice- I may also get them to do some work under contract
(such as testing our veterinary CT scanner).

The reason I posted to radsafe was to hear as wide a range of opinions as
possible.  So far the Radcal is winning hands down - I knew there had to be
something better than the Nero (or that it had improved).

Best regards

Mike
 

Michael Williamson                          ph +61 7 3365 4504
University Radiation Protection Adviser     fax +61 7 3365 1577
The University of Queensland                m.williamson@mailbox.uq.edu.au
Brisbane 4072
Australia


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