Indirect measurement
The indirect measurement (also called recovery mode or under bell) allows a considerable
gain in time as the flow which enters into the device is already stabilized.
The test pressure is first applied to the input of the part under test
1
and then to the
device 2. The output of the device 2 is vented to the atmosphere.
This method allows to test the parts at a higher pressure test (up to 2 MPa).
1 Part under test
2 Device
Depending on the part type, it may be possible to use a bell (ex: shower head where
it is impossible to recover the flow other than through the use of a bell). This method
can only be used if the recovery of the flow is easy.
PRINCIPLE OF A CYCLE
The measurement cycle is made of 4 main phases: fill, stabilization, test, dumping.
A Pressure auto zero additional phase 0 can be placed at the start or at the end of a cycle,
depending on the requirement of the operator.
0 Pressure auto zero phase
1 Fill phase
2 Stabilization phase
3 Test
4 Dumping