4. Operation
When the Nivotester FTC 422 is operating:
•
the green LED lights continuously,
•
the red LED lights when the relay output is de-energised.
The switching of the relay depends upon the fail-safe mode
selected.
Fail-safe modes Nivotester 422
This instrument operates with an upper and lower switch point
(see Figs. 9 and10).
Minimum fail-safe mode
The relay de-energises when the product drops below the lower
switch point: the red LED lights and remains lit until the product
rises above the upper switch point.
Level: rising again
Relay:de-energised
Red LED: lit
Level: falling
Relay: energised
Red LED: off
Level: <Min
Relay:de-energised
Red LED: lit
Level: >Max
Relay:energised
Red LED: off
Level
Relay
status
LED
status
Fig. 9
Operational sequence for
minimum fail-safe mode
Operation
Nivotester FTC 422
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