Emerson Rosemount 2501, Быстрый старт

Страница: 7 / 36

1.3 Measurement principles
Using a synchronous motor, the paddle (measuring vane) is driven to rotate
360 degrees.
When the vane of the paddle is not covered by a solids medium, a spring
pulls the motor and it switches a lug to the left position (
Figure 1-2 , top
illustration). The signal output indicates an 'uncovered' state and the motor
rotates the paddle.
When a solids medium covers the vane of the paddle, and causes the
rotation to stop, the lug is switched to the right position (
Figure 1-2 , bottom
illustration). The signal output indicates a 'covered' state due to a rising level
of material, and the motor is stopped until the vane becomes uncovered.
Figure 1-2: Switching Lug Function
B
A C D
A. Switching lug in left position ('uncovered' state)
B. Switching lug in right position ('covered' state)
C. Switch for stopping the motor
D. Switch for signal output
October 2019 Quick Start Guide
Quick Start Guide 7