TECHNICAL INFORMATION
21
87-900-120-01 (A)
6. Exerting a slight force in an upwards direction,
remove the pump
D
from its housing, releasing the
retention spring
E
.
7. Reverse the process to install a new pumping
element
8. Insert the new pump in retention spring
D
and then
connect the power and air supply using the two
non-reversible inlet and exhaust tubes.
USER INTERFACE
The PHD-4 helium leak detector is designed to operate
in different environments and in different applications.
The many different functions necessary to operate
efficiently in a wide range of different conditions are
managed directly by the microprocessor on the CPU
control board. The microprocessor guarantees
complete control of the capabilities and of the internal
components via the HID (Human Interface Device).
To start the HID and therefore to switch on the PHD-4,
press and hold down for at least 3 seconds the first key
A
to the right identified by the I symbol.
The HID starts and, after a short wait, the automatic
check on the internal blocks is started (Self test):
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.
A
D
E
D
