Toshiba Tohsiba Electromagnetic Flowmeter Converter L5232 - Manual (Page 155)

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Process error alarm
LCD display Description Corrective action
OVER 125%
The measured value is above the
125% of the span. The setting range for measured value
is narrow or the flow rate is
unexpectedly large. Check whether
the set value is correct or not and
check that there is no problem in the
process.
UNDER –125%
The measured value is below the
−125% of the span
The setting range of measured value
is narrow or the flow rate is
unexpectedly large. Check whether
the set value is correct or not and
check that there is no problem in the
process.
Fluid empty alarm
Detects that the fluid in the measuring pipe of the detector is empty and an alarm will be displayed.
If the alarm is set to OFF, this function does not work. For how to set this function, see 8.2
“Parameter Check/Change.”
(Note: In the case of LF232*F; Fluid empty alarm function is not usable. Set this function 'OFF'.)
LCD display Description Corrective action
EMPTY
Fluid is not filled in the measuring
pipe of the detector. Take measures to fill the pipe with
fluid.
Precautionary notes when using the fluid empty alarm
(1) Since the fluid empty alarm is detected using the impedance between the signal wires connected
to a pair of electrodes in the detector as well as the input signal level, a false alarm may be
detected by the following factors:
• Signal wire is broken or loose connection exists
• A large amount of air bubbles are mixed in the fluid
• Insulating materials are accumulated on the electrode
(2) In an environment where grounding is incomplete or excessive noise enters from the outside, the
fluid empty alarm may not work correctly.
In addition, under the condition like this, reliability of flow measurement itself decreases. Take
necessary measures to prevent the entry of noise such as making the ground complete
(independent Class D ground with grounding resistance 100
Ω or less) or reviewing the cable
wiring route.
(3) If the fluid still remains in the measuring pipe or deposits of conductive materials remain in the
measuring pipe, the impedance between the signal wires does not increase and the fluid empty
alarm may not work. In this case, use other method (such as a pump stop signal or a signal from
valves) to check the fluid empty condition.