NUCLEONIX SYSTEMS RC 705E Instruction Manual page 34

18Q) What is check source & why is it required?
A) Check source is a small (low level) Radioactive Gamma Source (Cs137). This is basically required to check
whether your Rad Check Meter RC705 is responding to radiation.
To check your Rad Check Meter, place the radioactive source close to the front face of the meter & observe the
meter reading to go up. When you take the source away, the reading drops.
This check source also could be used for carrying out QA of the product by verifying the stability of the reading
with source over the one year period when calibration is valid. Incase there is a drift of more than 10% with
respect to the initial reading when procuredfrom factory, contact factory as there could besome problem with
the instrument.
19Q) Does this "Rad Check Meter" indicate nuclide type and absolute level of contamination?
A) No, this meter primarily indicates (gross) or total contamination in relative terms. The reading also varies
with distance from the sample.
If your interest is to know absolute nuclide which has contaminated (such as Co-60, Cs-137, Am-241 etc.)
and its contamination level in terms of Bq/gm, then you need to go in for our Radioactive Contamination
Analyzer (Bq / gm system) RA 1006. This is a foolproof test and recommended for steel industry having
smelting/ induction furnaces.
20Q) Is there any Equipment offered by Nucleonix Systems to know the exact nuclide which has contaminated?
Whether the equipment can quantify the contamination level in Bq/gm or Bq/Kg?
A) Yes, we have a system already in our manufacturing range, which is being used now by many customers in
steel industry who have induction furnaces & manufacture products like billets, bars, flats, rods etc.
This system is called Radioactive Contamination Analyzer (Bq / gm system) RA 1006.
This system records gamma ray spectra of different isotopes present in the sample
under test & spectra can be analyzed to know the type of nuclide & also its
contamination level in terms of Bq/gm or Bq/kg.
21Q) Which unit of measurement is recommended for measurement in Rad Check Meter?
A) Since 'Seivert' is used in EU & UK it is better to measure in nSv/hr using Rad Check meter. Of course one can
also measure in ?R/hr, but has to use conversion factor for interpretation in ?Sv/hr or nSv/hr if required.
22Q) Can we have conversion from µR/hr' or µSv/hr' or nSv/hr to Bq, as Rad Check Meter does not measure in
Bq?
A) Conversion from µR/hr' or µSv/hr' or nSv/hr to Bq for a contaminated steel sample is difficult. Conversion
factor cannot be given right away for the following reasons.
One is size, shape, mass of sample & sample orientation distance from the detector probe face etc influence
while making measurement & hence one cannot give exactly any conversion. Also detector efficiency,
Background, also are to be accounted. Further since contaminated source is embedded into steel, there will be
self absorption.
It is possible to give conversion for a point source (standard source) if we know the type of nuclide.
Also in respect of contaminated steel samples, we are not sure that contamination spread, is uniform
(homogeneous) throughout themass. Precisely what wemeasure is what is emanating from the contaminated
sample which is measured & quantified. What is embedded deep inside, which may not be emanating because
of energy loss when the gamma photons reaches the surface of the sample will not be detected. Since it is not
emanating it is of no consequence.
Page 26 of 49