The easiest
and most obvious way to get data from your flow meter is to observe the local
display on the meter itself. This method is used frequently in basic
applications where a manual observation, and possibly a manual process
adjustment, is possible.
But what if you can’t get to the meter’s local display?
The best solution
would be to move the display to a location that’s more accessible. This is only
possible with flow meters that offer the
option of a “remote” display, whereby the display can be located away from the
meter sensing element. Under this configuration, the meter display and sensing
element are connected by wires or cables. The sensing element needs to be located
where the measurement takes place and the display must be placed where it can
be easily accessed for observation. Drawbacks include the potential need to
route the cables through solid objects (walls, doors, etc.) and the physical
distance that limits the cable itself.
There is
also the option of sending a signal representing the desired measurement from
the display itself. Many meters offer an analog and/or pulse output built into
the display. Instead of remote mounting the display, the display remains with
the sensing element and the analog or pulse signal is transmitted via wires to
a remote display or interface.
The
advantage of this method is simplification of the wires or cables needed to
transmit the signal verses the wires or cables needed to remote mount the
entire display. Additionally, this may be the only option if the flow meter does
not offer a remote display option.
The disadvantage
is that a second display or read-out is required to interpret the analog or
pulse signal, which increases total meter cost and complexity.
My local display shows a lot more information than I can transmit via analog or pulse. How do I get that information to a remote location?
That will depend on the capability and sophistication of your flow meter. In order to transmit more than just the most basic data, the flow meter must be capable of communicating via what’s known as “bus communication.” Specifically, the display would need to output a communication protocol such as HART, Modbus, Profibus, Ethernet, or something similar.
Of course,
the system complexity increases, and a receiver device that understands the selected
communication protocol will be required. This option also has the same drawback of having to install wires and
cables to transmit data.
I have an analog-, pulse-, or bus communication-capable display, but due to prohibitive costs, I can’t install the necessary cables to transmit my data to my desired remote location. What are my options?
There are various
wireless solutions for transmitting data from a flow meter to a remote
location. Basic devices will transmit the analog or pulse signal, while more
complex devices can transmit more data than the bus communication provides.
Here, the transmission is carried out via a radio-frequency signal. Range and capacity
need to be considered when selecting a system in order to ensure that all
communication needs are met. If the flow meter is outdoors and in a difficult-to-access
location, there is also the possibility of sending data over the telephone
cellular network.
