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Contamination Monitoring Sheet
Form
UEHS_FM
Doc
UEHS-L-001
September 2011
CONTAMINATION MONITORING
Instrument Make/Model
Detector Type
Detector Area
Click here to enter text.
Click here to enter text.
Click here to enter text.
Efficiency for radionuclide
Click here to enter text.
Last Calibration Date
Click here to enter text.
MDA (Bq/cm2)
Click here to enter text.
All values obtained by using the following equations
Instrument's Minimum Detectable Activity:
LLD (cpm) 
3  4.65  Background Counts  Counting Time
Counting Time
Add 10% wipe removal efficiency and
use 100 cm2 instead of Detector Area
MDA(Bq/cm 2 ) 
LLD (cpm)
Detector Efficiency  Detector Area  60 s
When NET Counts (Surface - Background) are GREATER than LLD:
A(Bq/cm 2 ) 
Net Counts (cpm)
Detector Efficiency  Detector Area  60 s
350 Victoria Street, JOR-1122, Toronto, Ontario, M5B 2K3
Tel: 416-979-5000 x 7096
Fax: 416-979-5205
Email: [email protected]
Web: www.ryerson.ca/irm
Add 10% wipe removal efficiency and
use 100 cm2 instead of Detector Area
UN(Bq/cm 2 ) 
(Counts  Counting Time) (Backgroun d Counts  Counting Time)

(Counting Time) 2
(Counting Time) 2
(Detector Efficiency  Detector Area  60s)
Counting Time is taken as 1 minute
1- For Direct Monitoring (no wiping):
0.3 Bq/cm2 contamination limit is equivalent to: Click here to enter text.CPM above Background
2- For Indirect Monitoring (counting a wipe):
0.3 Bq/cm2 contamination limit is equivalent to: Click here to enter text.CPM above background wipe
Monitoring Results
(CPM)
Wipe
(Y/N)
Background
Surface
Monitoring
Location
(see map)
Contamination
Status1,2
(Clean/Contaminated)
Date
(mm/dd/yy)
Performed
by
Page 2 of 4
Monitoring Results
(CPM)
Wipe
(Y/N)
Background
Surface
Monitoring
Location
(see map)
Contamination
Status1,2
(Clean/Contaminated)
Date
(mm/dd/yy)
Performed
by
Page 3 of 4
Monitoring Results
(CPM)
Wipe
(Y/N)
Background
Surface
Monitoring
Location
(see map)
Contamination
Status1,2
(Clean/Contaminated)
Date
(mm/dd/yy)
Performed
by
Page 4 of 4