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Self-Test
This automatic procedure is initiated by the HID each time the PHD-4
is started; this process is intended to guarantee that the
measurement made with the PHD-4 is effectively valid, checking
correct functioning of the components and of internal functions.
The self-test cycle comprises the following phases:
Test on the heater
Test on functioning of the HV power supply unit
Battery Pack test
Ion sensor starting test
Test on functioning of the ion sensor
Test on sampling effectiveness
The “Heater Test” function checks continuity of the platinum
resistor for heating of the permeable area inside the sensor.
Positive outcome of this test guarantees that the helium sampled,
together with the environmental gases, is able to penetrate inside the
sensitive element and can therefore be detected.
Efficient functioning of the sensor is verified by a further three tests,
the first of which is the “HV test”. During this test, a check is made
to guarantee that a correct voltage value is present at the output of
the HV power supply unit integrated in the helium sensor.
The “Sensitivity test” is useful for checking that the helium detection
sensor is able to start and is therefore operative.
The last test carried out on the sensor is the “Sensor test” consisting
in checking of the effective performance of the sensor.
The self-test cycle also includes a “Battery test” which checks that
there is a sufficient residual charge for operation of the PHD-4 and
the “Sampling test” which is useful for checking correct operation of
all the components involved in gas sampling (membrane pump,
sintered filter, glass wool filter, sampling line).
PHD-4 Portable Helium Detector User Manual
Technical Information
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87-900-120-01 (F )
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User Interface
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