ATTENTION:• It
is very dangerous to empty the meter
by
using
air, nitrogen or steam. If it is necessary be very
careful
during the operation. emptying will inevitably damage the
meter.
FAULT FINDING
If the metering system is not functioning correctly:
First check the operation of the indicator or control
instrument correctly:
Disconnect the signal input connections to the instrument
and simulate the pulsations of the reed switch at the
meter by intermittently short circuiting the input signal
terminals at the rear of the instrument. If the appropriate
pulses are not received on the indicating or control
equipment, then there units must be checked as described
in the appropriate instruction manual. If pulses are
received and indicated then re-connect a signal input
cable.
Check that the interconnection cable is satisfactory by:
Disconnecting the other end of the cable from the reed
switch connection. Short circuit the conductors and see
whether or not pulses are received on the control
equipment at the other end of signal cable. If pulses are
not received then there is a break somewhere in the
interconnection cable and it should be replaced. If pulses
are received re-connect the cable.
Check the operation of the reed switch by:
Remove the head assembly from the meter and connect a
battery ohm meter. Pass a normal magnet across the
bottom of the reed switch and if the resistance changes
from at test I mega ohm to less than I ohm due to the
movement of the magnet, the reed switch is operative.
To check that the disc is rotating whilst liquid is flowing:
I) Hold an ordinary magnetic compass near the reed
switch recess in the meter body. If the needle oscillates
wildly the disc is moving.
2)
A visual check can be mode on the quantity of liquid
flowing through the system with the control device fully
open. If the flow rate is drastically below that normally
delivered the disc could be stationary and helping to produce
a prohibitive head loss across the meter.
3)
Adjust the system flow rate to its maximum and check
for a slight vibration of the meter
Pag.9
