NUCLEONIX SYSTEMS RC 705E Instruction Manual page 32

7Q) What is a G.M detector based Radiation monitor? Whether one can use it for checking of Radioactive
Contamination in steel / iron/ alloy / castings products?
A) Low cost G.M. detector based meters are offered by some companies & they cannot detect low level radioactive
contaminations. Higher contamination levels, only they can detect & hence are not recommended for this
application.
Only sensitive meters which can measure Dose rates from 1µR//hr or 10 nSv/hr onwards are to be used. At
Nucleonix System we have a product called Rad Check Meter in our range. This is a portable meter to be used
either with internal or external probe.
8Q) When Truck/Container Monitoring System is to be used for Radioactive Contamination? How does this help?
A) This system comprises of two large volume plastic scintillator detector pillars, electronic measuring & alarms
unit andsoftware with PC. Highly recommended at the entry/exit gates to check for radioactive contamination
in. In-coming trucks/ containers carrying scrap metal, input raw material, iron, steel, alloy products etc. Also it
can be used for checking outgoing finished goods in trucks / containers.
Inspection at the 1st entry level saves the industry from buying contaminated scrap metal & saves on electricity
bills & other processing costs by melting the scrap metal in smelting furnaces
9Q) When Radioactive Contamination Analyzer (Bq/gm system) for Nuclide Identification & its quantification is
to be used?
A) This is a powerful tool used for exact quantification of nuclide, present in a contaminated sample. This system
identifies & quantifies the contamination in Bq/Kg or Bq/gm of the sample. This is an ideal choice in quality
assurance departments of all steel. / iron / alloy/Foundry casting industries (medium & large). This facilitates
loading of sample up to 1 to 2 kg on to the detector area, for measurement.
10Q) What is the 'unit' of measurement that is normally used in these above systems?
A) Normally the units used in these meters globally are Sv (sivert). In India we have been using R (Roentgen).
But Nucleonix Systems has been providing both these units Sv & R. Additionally meters may have CPS , CPM ,
modes. All Nucleonix meters have FOUR modes of operation nSv/hr, µR/hr, CPS, CPM.
In the Rad Check Meters you may find m R/hr (micro roentgen / hour) & nSv/hr (nano sivert / hour)
m = micro = 10
-6
n = nano = 10
-9
m = milli = 10
-3
11Q) Can we have some idea on measuring units used? How do you define Sv & R ?
The SI unit of dose equivalent
1 Sv = 1 J /kg (one 'Joule' of energy deposited 1 kg of air)
Roentgen (R) : Is defined as the exposure that results in the generation of 1 electro static unit of charge (2.0 g
X 10 ion pairs) per 1 cm3 of air STP (0.001293 gms)
9
1= 2.58 X 10 C/Kg.
-4
Gray: Absorbed dose is a measure of energy deposition in any medium by all types of ionizing radiation and
1GY = 1J/Kg
Since an exposure of 1 R results in an energy deposition of 869 X 10-5 J/Kg in air it follows that
1 R = 869 X 10 Gy
-5
1 R = 8.69 m Gy
1 R = 10 m Gy
1 R = 10 m Sv
1 Sv = 1R/10m
1 Sv = 100 R
milli (m) =
micro (?) =
nano (n) =
10
-3
10
-3
10
-9
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