InstroTek
11
Standard Count
Taking a Standard Count
Note: A new standard count should be taken at least once a
day.
With the case on the ground, place the gauge on the CPN
nameplate depression on the top of the case. No other
radioactive sources should be within 30 feet of the gauge, and
no source of hydrogen should be within 10 feet after starting
the reading.
To initiate a new standard count, press
STD
. The display will show
the last standard count and asks you “Would you like to take a
new STD Count?” Select either
(Yes/No)
.
The wax in the shield is not an infinite volume. Thus a standard
count taken in this manner is subject to surrounding conditions.
It is important that the standard count be taken in the same
conditions as that used to establish the calibration, and that the
conditions are the same each time.
See section 11 for further discussion on standard count.
Select TIME
The counting time is selected by pressing the
TIME
button on the
keypad.
For a given counting rate, the counting time interval determines
the precision of the measurement. The longer the time
selected, the more precise the measurement. Correspondingly,
the longer the counting times the fewer measurements that
can be made in a day. Thus the time interval is normally
selected as the minimum time that will meet your specific
precision.
