Power Failure; Adjustment For Manual Mode; Low Cut Adjustment; Tuning - YOKOGAWA DY025 User Manual

6.1.8 Power Failure

When a power failure occurs, the totalized value will be
protected by EEPROM (Electrically Erasable Programmable
ROM). But during a power failure, the vortex flowmeter
stops and also the totalizing will stop.
After a power is recovered, the vortex flowmeter and the
totalizing start to work automatically.
EEPROM doesn't need a battery for backup.

6.2 Adjustment for Manual Mode

digitalYEWFLO does not need the initial adjustment because
digitalYEWFLO is always adjusted by itself automatically.
These adjustments should be done in case that
indicator reads over zero at zero flow.

6.2.1 Low Cut Adjustment

Adjust to noise elimination or zero flow in the low flowrate
(or low frequency) range.
The settable range for low cut flowrate is to half of mini-
mum flowrate.

6.2.2 Tuning

This adjustment should be done according to a flow figure
shown below.
START
Is it zero flow?
Yes
Set "TUNING AT ZERO"
of "K25:N.B MODE"
Wait more than 30 seconds
Ensure the complete of the
tuning function.
Is indication reads zero
at zero flow?
No
Retry the tuning and ensure
the pipeline conditions?
If this adjustment is executed, the following value is
changed.
K25:N.B MODE = MANUAL
K26:NOISE RATIO=Constant value
Minimum flowrate is increased when TLA value is
changed form initial value.
6-3
6. OPERATION
No
Stop flow to be zero
Yes
Finishing the tuning
functios
Ensure TLA value
F060201.EPS
IM 01F06A00-01E