To measure air flow that contains saw dust
A simple process, containing an air blower that carries saw dust through a duct. Saw dust eventually gets collected in a bin.
My customer requirement is to shutdown the air blower when there is a blockage in the duct due to piling of the saw dust.
What can be the measurand and control loop for this application?
Budget available is meagre for hefty hardwares.
The blockage will cause an increase in pressure in one area of the duct and a decrease in another. A differential pressure measurement should detect this change.
If the duct is blocked then the usual solution is to alarm before eventually shutting down the process to clear the blockage.