2 recalibration procedure, Recalibration procedure – BNC SAM 935 Portable Gamma Spectroscopy System User Manual
SAM 935™ Instruction Manual
The dose rate analysis measures and records isotopes in dose rate units (rather than the confidence levels
used by the Monitor mode). The different modes of operation are explained in Section 5.
An example of the main dose rate monitoring screen is shown below:
If there are stored alarms, you can review them by pressing the
arrow keys from the main
Surveillance monitoring screen:
If other display modes are enabled, they will show up as options under the F1 function key. Display modes
are discussed in Section 5.
Follow the directions in this section to perform a complete recalibration of the SAM 935. To ensure accu-
rate, reliable results, you should recalibrate the SAM 935:
• when you first install it. It is calibrated at the factory, but it should be recalibrated on site to ensure
reliable results. This requires only a coarse adjustment and background spectrum, and can be
done with the one-button quick calibration on the main screen (F2). See Section 4.2.1 for details.
• whenever the temperature changes drastically (such as moving from indoor to outdoor monitor-
ing). This requires only a coarse adjustment and background spectrum, and can be done with the
one-button quick calibration (F2). See Section 4.2.1 for details.
• if you change the type of detector you are using with it; this requires a coarse and fine calibration.
• If you perform a memory reset.
You perform this 3-step recalibration process from the
Calibrate Area Monitor option in the Utilities menu.
This calibration method automatically adjusts hardware parameters such as high voltage and amplifier
gain to achieve a proper energy calibration for the system. The quick calibration method described in Sec-
tions 1.2.2 and 4.2.1 does not.
Press the U
key to bring up the Utilities menu.
The dose rate units are recorded in metric abbreviations
of Sievert (Sv) or REMs (R).
Press F2 to return to Surveillance mode and take more
Press F3 to print the stored alarm(s); see Section 7.1
for more information about this report.