Preamble
UM-22100H-U User manual ATEQ D520 Page 8/122
3.2. INDIRECT MEASUREMENT (OR RECOVERY MODE)
Test part
Air supply
Absolute
pressure
sensor
Calibrated flow tube
Regulator
Atmosphere
Differential
pressure sensor
Flow
Dp
The calibrated flow tube is placed following the output of the test part. The output of the
calibrated flow tube is to the atmosphere.
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.
The indirect measurement allows a considerable gain in time as the flow which arrives
in the calibrated flow tube is already stabilised.