1.3
Measurement principles
Using the principle of a tuning fork, a piezo-electric crystal oscillates the
forks at their natural frequency. Changes to the oscillation frequency are
continuously monitored by electronics which varies depending on whether
the fork is covered or uncovered by a solids medium.
When the solids medium in the vessel (silo) falls away from the fork, it causes
a change of oscillation frequency that is detected by the electronics and the
output switches to indicate an 'uncovered' state.
When the solids medium in the vessel (silo) rises and covers the fork, it
causes a change of oscillation frequency that is detected by the electronics
and the output switches to indicate a 'covered' state.
The electrical output will vary depending on the electronics selected when
the Rosemount 2521 was ordered.
October 2020
Quick Start Guide
Quick Start Guide
9