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Actual operation, 1 pre-operation zeroadjustment, Actual operation -1 – Yokogawa ADMAG AXR User Manual

Page 138: Pre-operation zero adjustment -1, Important, 1 pre-operation zero adjustment

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<10. ACTUAL OPERATION>

10-1

IM 01E30D01-01EN

After you have installed the flowtube into the

process piping, wired the input/output terminals,

set up the required parameters, and performed

a pre-operation zero adjustment, the magnetic

flowmeter should output an accurate flow signal

from its terminals as soon as flow of the fluid to be

measured begins.

IMPORTANT

Warm up the instruments for at least 30 minutes.

Perform flow measurement 30 minutes after

turning on the power.

This section describes zero adjustment and the

corresponding procedures.

10.1 Pre-operation Zero

Adjustment

Zero adjustment is carried out to ensure that the

output for zero flow is 0%. Although adjustment to

zero is performed at the manufacturing plant prior to

shipment, this procedure must be carried out once

again following the installation of piping in order

to match the magnetic flowmeter to its operating

conditions.

This section describes the zero adjustment

procedure using display unit switches from the

converter and using the external status input;

accordingly, one of these methods should be

selected and implemented.

10. ACTUAL OPERATION

IMPORTANT

• Zero adjustment should be carried out

before actual operation. Note that parameter

settings and update functions cannot be

carried out during this procedure (i.e., for

approximately 450 seconds).

• Zero adjustment should only be carried out

when the flowtube has been filled with the

measurement fluid, wait 10 minutes, and the

fluid velocity is completely zero by closing

the valve.

• Each time that the fluid being measured

is changed, it will be necessary for zero

adjustment to be carried out for the new fluid.

• While zero adjustment is being carried out,

normally a current of 10.4 mA is output.

Since the current of 10.4 mA is output, when

zero adjustment is carried out, first change

the control loop to the manual mode, and

then set this parameter.

• Zero adjustment cannot be carried out during

occurring various alarms.