Entering Channel Data; Activating A Channel - GE DigitalFlow DF868 Programming Manual

Entering Channel Data

Activating a Channel

Programming Site Data
While following the programming instructions, refer to the menu map
in Figure A-1 on page A-1 or Figure A-2 on page A-2. After selecting
[F1]=CH1 [F2]=CH2
(or ) at the initial programming screen, the
following screen appears:
Chan 1 PROGR
Channel PROGRAM
status
ACTIV SYSTM PIPE
Based on the selection made above, proceed to the appropriate section
of this chapter for instructions.
ACTIV
The submenu activates a channel and selects the desired
measurement method.
Channel PROGRAM
1. To enter the
on the desired channel) at the
ACTIV
2. Enter the submenu by pressing
prompt.
[F1]
3. Press to deactivate the channel,
Transit-Time
mode, or
The Model DF868 flowmeter can take measurements in two ways:
•
The Correlation Transit-Time™ technique uses a pair of
transducers (either wetted or clamp-on) with each transducer
alternately sending and receiving coded ultrasonic signals through
the fluid. When the fluid is flowing, signal transit time in the
downstream direction is shorter than in the upstream direction; the
difference between these transit times is proportional to the flow
velocity. The DF868 measures this very small time difference and,
using various digital signal processing techniques combined with
programmed pipe parameters, determines the flow rate and
direction.
®
•
The TransFlection technique uses two transducers. One
transducer shoots thousands of grouped ultrasonic pulses in very
rapid succession. The pulses bounce off "scatterers" in the liquid
(bubbles, solids, or liquid droplets) and are reflected back to the
other transducer. Each received pulse group receives a "snapshot"
of the flow. By comparing all snapshots and averaging out objects
that do not appear to move with the flow, the DF868 can determine
flow rate and direction.
Note: If the DF868 has not been ordered with TransFlection mode,
the TRNFL option does not appear.
Proceed directly to the next section to program the
Start ‰ Press the [←] and [→] keys and
a function key
the desired submenu. From this
[EXIT]
screen, press
the initial User Program screen
shown on page 1-8.
I/O
[F1]
menu, press
User PROGRAM
prompt.
[F1]
at the
[F2]
to activate Channel 1 in
[F3] TransFlection
to activate
March 2008
[F1]-[F4]
to select
to return to
[F2]
or (depending
Channel PROGRAM
mode.
SYSTM
submenu.
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