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20
MAN-147-0018-A
Calibration Process (using applied pressures):
This method can be used by an authorised service center to pair and calibrate a
pressure sensor to the logger.
The method consists of applying reference pressures to the transducer and building a
table of calibration values.
5.4.
F
LOW
S
ENSOR
I
NPUT
(
METER PULSE COLLECTION
)
Depending on the model supplied, the logger may have 0, to 6 Flow inputs. These are
digital inputs, designed to sense the open or closed condition of a switch (activated by
the installed meter). To use the flow channel(s) the logger must be set up (using IDT) to
know what each meter pulse represents.
5.4.1.
E
XPLANATION OF
F
LOW
C
HANNELS
&
I
NPUT
S
IGNALS
Flow of a fluid in a pipe is usually detected by a meter, which produces pulses related to
the volume of fluid passing through it. There are several types of meters; some can
detect both forward flow and reverse flow (bi-directional flow); some can detect flow in
one direction only (uni-directional flow). There are therefore several ways of
implementing the meter pulse output signals from a meter. Your logger must have the
correct interface and settings for the signalling from the meter to be compatible with it.
The Multilog2 Flow inputs sometimes require two input signals in order to work with the
meter-pulse signalling of certain meters. A pair of inputs can therefore sometimes be
configured to operate as a single channel. Other meter types only require one signal, so
the pair of inputs can operate as two separate channels.
The pair of Flow signals can be labelled in one of the following ways:
Alternative signal names
Pair of
FLOW
signals
Flow Input 1
Flow 1
Pulses
Flow (Forward)
Flow Input 2
Flow 2
Direction Flow (Reverse)
Common
GND
The labelling depends on the factory default for the configuration of the Flow channels
on your logger model-number, but sometimes alternative types of configuration can be
achieved by changing logger settings.
Where the logger is
pre-configured by the factory to produce only 1 Flow channel
(datapoint stream), the pair of inputs can be used in one of three different ways:
(1) Input 1 can be used with a
Uni-directional meter
(one which only measures
forward flow / consumption).
For use in this configuration:
•
Input 1 acts to collect meter pulses, and