Polimaster PM1704A, Руководство по эксплуатации, Страница: 12 / 27

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2. OPERATION
2.1. Turning the instrument ON/OFF
To turn the instrument on, press and hold down the MODE/SET button. If
the battery is good, the audio and vibration alarms are initiated for a
short period of time, and then the display briefly shows the firmware
version and battery charge level before initiating self-test procedures.
The message “TEST” is displayed during this operation.
To turn the instrument OFF, go to the SETTINGS menu and select POWER
OFF. The LCD will display the “POWER OFF” message and after a couple
of seconds goes blank. Now the instrument is turned off.
2.2. Going through self-tests and background calibration
After the self-tests are completed the audio and/or vibration alarms are
activated for approximately 1 second before the instrument initiates the
background calibration. The message "CALIBRATION" is displayed on the
LCD during this process, in which the instrument measures the gamma
radiation background and calculates alarm levels given a value of n
coefficient2. After background calibration is finished, PM1704A is ready
for normal operation.
2.3. Normal operation (Search mode)
When self-tests and background calibration are finished the instrument
is ready for operations and automatically goes into Search mode. In
Search mode, the instrument displays the current value of gamma and
neutron radiation (for gamma-neutron models only) in counts per
second (cps) and automatically compares it with the threshold value
obtained during background calibration.
This allows the user to effectively search and locate radioactive sources.
When a radioactive source is detected (the calculated threshold is
exceeded), the instrument’s visual, audible and/or vibration alarms are
triggered. As the PM1704A moves closer to the radiation source, the
frequency of audio and/or vibration signals increases thus enabling the
user to determine the direction of the source location.
When the alarm signals reach maximum frequency it is recommended to
run the background calibration procedure (see section 2.3.1.) while
keeping the
location of the instrument unchanged
. After background
calibration is completed, the user may continue to seek the location of
the radiation source. If necessary, this procedure may be repeated
several times until a gamma radiation source is located.
2
See section 2.3.2 for more information.