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Alicat V Series Volumetric Flow Meter User Manual

Page 18

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V Series Volumetric Flow Meter Operation

The V Series can have several screen “modes” depending on how the device is ordered. All V Series

meters have a default Main Mode, Select Menu Mode, a Gas Select Mode (the Gas Select Mode

may not be available on meters calibrated for a custom gas or blend), a Communication Select Mode,

Manufacturer Data Mode and a Miscellaneous Mode. In addition, your device may have been ordered

with the optional Totalizing Mode (page 38). The device defaults to Main Mode as soon as power

is applied to the meter. Note that volumetric meters are intended for use in near atmospheric

conditions (Please see page 28).

Main Mode

The main mode screen shows the volumetric flow in the units specified at time of order. In the flow

mode, only two buttons are active as shown in Figure 12. The process gas that is selected is shown

directly under the flow units.

Tare

Volume
CCM
Air

+0.000
Volume Main

Figure 12. Main Mode Display, V Series Flow Meter

The “MODE” button in the lower right hand corner toggles the display between the Main Display and

the Menu Display.

Tare – Pushing the dynamically labeled “Tare” button in the upper right hand corner tares the flow meter

and provides it with a reference point for zero flow. This is a simple but important step in obtaining

accurate measurements. It is good practice to “zero” the flow meter each time it is powered up and

whenever a known zero flow condition exists. If the flow reading varies significantly from zero after an

initial tare, give the unit a minute or so to warm up and re-zero it.
Zeroing the unit while there is any flow will directly affect the accuracy by providing a false zero point.

If in doubt about whether a zero flow condition exists, remove the unit from the line and positively block

both ports before pressing the “Tare” button. If the unit reads a significant negative value when removed

from the line and blocked, it is a good indication that it was given a false zero. It is better to zero the

unit at atmospheric pressure and a confirmed “no flow” condition than to give it a false zero under line

pressure.
Note: A remote tare can be achieved by momentarily grounding pin 4 to tare as shown in Figure 5 on

page 9.