8
BEFORE INSTALLATION (continued)
Using the Meter (continued)
To zero the Batch Total, make sure the meter is on. Hold down the DISPLAY button
for 3 seconds until zeros appear. Release the button, start the flow, and watch the
volume on the readout.
When display becomes dim, faded or the low battery message (LOWBAT)
appears, the batteries need to be replaced. Reference the Computer Maintenance
Section for details.
METER INSTALLATION
Review the Before Installation and Quick Start Sections. Also consider the
following recommendations, especially if you are installing your meter in a piping
system. These suggestions will help maximize performance of your meter.
The meter can be mounted either vertically or horizontally. It should be field
calibrated in the same orientation in which it is mounted.
Avoid installing the meter in electrically “noisy” environments. If installed within 6
inches (15.2 cm) of large motors, relays, vehicle ignition systems, or transformers,
the meter’s accuracy can be adversely affected.
To avoid pulsation or swirl, use the following recommendations:
•For Low Flow or one inch meters, install with:
20 inches (51 cm) of straight pipe upstream and
5 inches (13 cm) of straight pipe downstream.
•For two inch meters, install with:
40 inches (102 cm) of straight pipe upstream and
10 inches (26 cm) of straight pipe downstream.
Flow straightening vanes installed upstream from the meter can reduce the
upstream pipe length.
Flow control valves upstream from the meter and within the straight pipe distances
given earlier can adversely affect meter accuracy. This is especially true when
measuring liquids with low vapor pressures such as fuels, oils and solvents.
If cavitation effects meter accuracy, a flow control valve on the downstream side
of the meter can provide a back pressure of 5 to 50 PSI (0.3 to 3.4 bar) to minimize
the problem.
Foreign material in liquid can clog the meter’s rotor. If the problem affects meter
accuracy or material coats the rotor, install screens to filter the incoming flow.
•For Low Flow meters use a 25-micron or .005 inch screen, 120 mesh.
•For one inch or two inch meters use a 500 micron or .018 inch screen, 35
mesh.
For maximum accuracy, the velocity profile of the flow entering the meter must be
uniform throughout the cross section of the pipe.
Make sure there are no leaks in the connections. To seal leaks, remove and
inspect the meter and replace the thread tape or sealant. Refer to the
Troubleshooting Section.
