BEKA BA538C, Руководство пользователя, Страница: 4 / 26

4
2.3 Displays
The BA538C has two digital displays and
associated annunciators, plus a flow indicator as
shown on page 1.
Rate Shows the flow rate on the
Display smaller six digit display.
Total Shows the total flow on the
display larger eight digit display. Set to
zero when local or remote reset
switch is operated.
Flow This disc in the lower left
indicator hand corner of the display 'rotates'
for two seconds each time an
input pulse is received. Therefore
when the pulse input frequency
exceeds 0.5Hz the disc appears
to rotate continuously.
Hold Activated when input
Annunciator frequency is below the clip-off
threshold.
Reset Activated when the instrument
Annunciator is being reset .
3. SYSTEM DESIGN
3.1 Flow transmitter loops
The BA538C may be connected to almost any
pulse output flowmeter and calibrated to display
rate of flow and total flow in the same or different
engineering units.
Fig 2 illustrates the basic circuit that is used for all
BA538C installations. For simplicity, connections
for the optional pulse output, 4/20mA output and
backlight are included in section 8 of this manual.
Fig 2 BA538C in flow application
When designing a system it is important to
remember that terminals 2, 4, 6 and 8 are
interconnected within the BA534D - see Fig 1.
3.2 Power supply
The BA538C may be powered from any dc supply
having an output voltage between 10 and 30V.
The instrument consumes about 12mA rising to
15mA when a proximity detector input is used.