Operating Guidelines for Liquid Flow Meter Kits
www.sensirion.com
Version 1 – D1 – June 2019
page 16/18
Since the sensor relies on a thermal measurement principle through the wall of the capillary tube, one must
take precautions to avoid any build-up or deposits that could alter the thermal properties of the capillary
and thus influence the sensor’s reading.
Before storing the sensor, always drain the fluid, flush with cleaning agent. In most cases flushing with
distilled water, then acetone, and finally IPA will suffice. Then blow the senor dry with pressurized air. Sen-
sor plugs should be installed for storage. The cleaning agent (detergent, solvent, etc) should be chosen for
its effectiveness in removing the liquid media and compatibility with wetted materials.
Flow meters do not need periodic cleaning unless the medium has a tendency to leave deposits, or flow
meters have been disconnected from the fluidic path and not properly flushed. The residue left by the drying
fluids can alter sensor performance or even plug the capillary. You may try cleaning it by flushing with
acetone and IPA.
Never
attempt to mechanically clean the sensor’s flow channel.
For details, consult the Application Note Cleaning and Clean Handling at