Geiger
Counter Watch and Much More!!!!! You just
gotta have one!!!
Last
December, our labs acquired a Gamma Master
watch from Latitude Limited out of Hong Kong.
Our purpose was to determine how effective this type of radiation detector
would be in real working situations. This was the best decision we have
made in a long time. Not only did the watch live up to its publicity, we had a
great time testing (playing with) it over the past few months. This watch is a must-have
for all radiation professionals.
There
is no substitute for the radiation professional being able to know his accumulated
Dose Equivalent or the background readings at all times. It gives the professional
a live sense of the radiation environment never truly known before.
With
the new emphasis on radiation terrorism, we recommend this watch for use to detect
dirty weapons by anyone concerned - police – customs – firemen – etc... etc. .
During
our evaluation of the watch we used it all over the world. It never deviated from
being consistent with larger instruments for detecting background radiation through
fairly high levels during our work and during training courses. We compared its
readings over the test period with a Victoreen Scintillation Counter Model 190/429.
It stayed within 5% of the readings we had using the Victoreen Instrument. Considering
the watch case next to the technicians wrist versus the probe
of the Victoreen extended away from the body… we were impressed.
Not only could we use
the watch as our radiation detector, it gave us a running account of accumulated
Dose plus background level changes. The background of our labs ranged from 0.09
mSv/hr to 0.35 mSv/hr. The average was approximately 0.13 mSv/hr. It
is truly a joy to be able to see bursts in background due to sun spot activity
or other unknown sources.
When
we were doing radiation surveys, we could add a feature to our reports: background
level changes. The Gamma Master is
amazing to be so sensitive to allow such a report. Most of us who do surveys only write down the
“hot” spots. With the Gamma Master the
professional is able to determine real time changes to the background in the area
making this a true ALARA Tool.
During
our travels, we took many airplane trips with the Gamma Master. What a professionally interesting
gadget is this watch that allows us to see the increases in our radiation exposure
as the airplane climbs through the atmosphere. The following table is one we use
during our training sessions on Radiation Safety. The Gamma Master
followed this table at least as high as we traveled in normal commercial
jetliners. We saw a high of 6.00 mSv/hr
at approximately 35,000 feet several times across the USA and to Europe. Typically
the Dose Rate was approximately 3.5 mSv/hr
for most trips. We saw very little changes
during the first 15,000 feet of climb but afterwards the background rapidly changed
as the airplane reached cruising altitudes.
| Altitude |
Average Annual Dose (mSv) |
Average Dose Rate (mSv/hr) |
|
| | |
|
Sea Level | 1.3 | 0.15 |
|
5,000 | 1.8 | 0.21 |
|
50,000 | 90.0 | 10.3 |
|
80,000 | 120.0 | 13.7 |
When
we went through airport security we had to place the watch on a separate carrier
as we did our cell phone and laptop computer. Each time the watch came through
the X-ray machine fine. It was alarming its heart out but functioned beautifully...
that is all times except one. Dallas Fort Worth Airport Delta check-in blew our
beautiful Gamma Master. We believe the X-ray
machine was set a "little high." I wonder how the leakage is for the
workers there? With the new security arrangements, one may not ask such questions
at the check point without the possibility of being labeled a "problem."
We
sent our Gamma Master back to Latitude for repair. It was returned very quickly.
Take
our word for it. This is a necessary piece of equipment for all radiation professionals.
Get One.
The
Gamma Master has four distinct displays:
The analog watch face, a graphic display of Dose Equivalent Rate, a graphic
display of Accumulated Dose Equivalent and
a digital readout which may be switched between Dose Equivalent Rate, Accumulated
Dose Equivalent and time.
The
following are the features on the watch’s data sheet.
Detecting
Gamma-radiation with Geiger-Muller tube
Measurement of Dose Equivalent
Rate (DER) and Dose Equivalents (DE) of Gamma-radiation
Graphical and digital indications for DER and DE
User set DER and DE audible alarms
Digital watch
displays hour and minute, date and second
Daily
alarm
Analog watch indicates hour, minute and second
Electro-luminescent
back light
Metal case, metal band and switch buckle
DER indication range: 0.1 to 4000mSv/h (0.01;0.1;1.0;10.0;100)
DE indication range: 0.0001 to
9999mSv
DE threshold range (step): 0.001 to 9999 mSv (0.001;
0.01; 0.1;1.0;10.0;100)
DE accumulation time range: 1
to 9999 h
Accuracy of indication of DE:+/- 25%
Energy range: 0.06 to 1.5 MeV
Measurement time decreases
automatically in the range: 300 to 2 s
Latitude
Limited
Health-care Watch
Series
11/F., Hoi Hung Industrial Building
25-27
Lam Tin St
Kwai Chung
N.T. Hong Kong
Tel: (852) 2410 0338
Fax:
(852) 2494 0993
www.hkenterprise.com/latitudeltd
email: mkt@latitude.com.hk
GammaMaster