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Radiation Meters
| Radiation
meters are used to detect ionizing radiation. In general ,all laboratories that work with radioactive materials are required to posses a radiation detector. Below are recommendations for the detector type
your lab requires, who you may purchase a radiation
meter from, and how to get your meter calibrated. |
Radiation Detector Types
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Geiger
Mueller (GM)
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Scintillating
(NaI)
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- Generally used
for detecting Beta Emitters
- This
model is also known as a "Pancake" probe.
- Detects
radiation via the ionization of a gas contained
inside the probe. The ejected electrons are
then collected and counted.
- Probe
has a very thin membrane that is under pressure
and easily punctured.
- Capable
of detecting alpha and gamma radiation but with very
low efficiencies. Not the preferred the meter
for detecting these radiation types
- Not able to
detect H-3.
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- Generally used
for detecting Gamma Emitters
- Detects
radiation via the interaction of ionizing radiation
with a scintillating crystal containing Sodium
Iodide(NaI).
- Laboratory
MUST obtain a NaI probe when working with I-125.
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Commonly used
to detect:
C-14, Ca-45, P-32, P-33, S-35 |
Commonly used
to detect:
I-125, Cr-51 |
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Purchasing
a Meter |
When ordering a Meter, both the scaler and detector need to be purchased. The Geiger Mueller and NaI probe are probes (detectors) that attach to the survey meter (scaler). The probes are interchangeable with the same type of survey meter. The most common radiation detector is the Ludlum Model 3 with a Model 44-9 pancake probe. Ludlum Meters are the most commonly used meters of at Rutgers and RWJMS
Ludlum
Vendors
Once
a meter is ordered and received by the lab, contact REHS
so that an efficiency check may be performed
and the meter added to the REHS database.
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Calibrations/Repair
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Laboratory meters are checked once per year via efficieny checks. An efficiency
check entails checking the efficiency of the meter against
a known P-32 and C-14 check source for pancake probes, and an I-129 source for NaI probes.
If the efficiencies fall within certain parameters, the meter is considered
acceptable. If the meter fails an efficiency check, REHS
can try to resolve the problem in-house, but may need to send
it back to the approriate vendor for repair. The lab is expected to cover
the cost of any repairs to a meter should the need arise.
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Contacts
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Overall Program
Management - Nick Taylor or call (732) 445 - 2550 |
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Health
Safety Specialists (By Campus Assignment), or call
(732) 445 - 2550 |
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| For more information, contact webmaster |
Last Updated:11-12-09 |
© 2009 Rutgers, The State University of New Jersey. All
rights reserved. |
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