RESPONSE
The response of this type of ionization chamber has been
carefully studied using radionuclides calibrated at the Na -
tion al Institute of Standards & Technology. The result is a
well-defined energy response curve which is used to deter-
mine the calibration values for many different isotopes with
high accuracy. Each chamber has been calibrated with a
Na tional Institute of Standards & Technology traceable
source. The corresponding Calibration Value has been
stored in the memory of the Detector Unit. After calibration,
the chamber's accuracy is tested with several sources of dif-
fering gamma energies whose activity values are traceable
to the National Institute of Standards & Technology.
THE DISPLAY UNIT
The Atomlab Dose Calibrator Display Unit consists of control
keys and displays that allow you to make activity measure-
ments. A built-in microprocessor executes commands input via
the front panel keys and computes activity values from
Detector data.
The Display Unit, with a molded plastic case housing the
electronics, has been specifically designed to perform Activity
Measurements in a laboratory setting. To allow easy fingertip
control of the keys, the front panel slopes gradually. The
Activity Display slopes as well, providing an optimum viewing
angle. On the rear panel of the unit are the power and com-
munication connectors, and the power switch, which remain
out of the way as they are infrequently needed.
ZERO CALIBRATION
The innovative design of the Atomlab's Dose Calibrator's
electrometer ensures that this zero adjustment is performed
while measurement of the activity values is being carried
out, and is therefore continually updated.
The current from the chamber is collected on a capacitor in
the feedback loop of the electrometer whose capacitance
value is stable and measured to a high degree.
ATOMLAB Dose Calibrator Operation Manual Chapter 4
Biodex Medical Systems 4-3 Release 2.0
Method
To Next Page
Loading...