BEKA BA537E, Руководство пользователя

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9. ACCESSORIES
Accessories for the two models differ as shown below,
all except the scale card, are factory fitted and should
be specified when the instrument is ordered:
BA537E BA538E
96 x 48mm 144 x 72mm
Scale card Scale card
Tag number Tag number
Backlight
1
Backlight
1
Isolated dual alarms 2 Isolated dual alarms
or
Isolated 4/20mA output 2 Isolated 4/20mA output
or
Isolated pulse output 2 See note 3
Notes:
1. Internally powered
2. Only one of the three output options may be
fitted to a BA537E.
3. All BA538E Rate Totalisers are fitted with an
isolated pulse output.
9.1 Scale card
Both models have a window on the right hand side of
the display through which to view a scale card
showing the units of measurement such as Gals/hour
or Litres. New Rate Totalisers are fitted with a scale
card showing the units of measurement specified
when the instrument was ordered, if the units are not
specified a blank scale card will be fitted. A pack of
scale cards pre-printed with common units of
measurement is available as an accessory. These
can easily be fitted on-site to the Rate Totaliser
without opening the instrument enclosure or removing
it from the panel, See section 4.4 of this instruction
manual.
Custom scale cards for applications requiring less
common units of measurement are also available.
9.2 Tag information
Both models can be supplied with a tag number or
application information thermally printed onto the rear
panel adjacent to the terminals. This information is
not visible from the front of the instrument after
installation.
9.3 Backlight
The BA537E and the BA538E Rate Totalisers can
be supplied with a factory fitted backlight that
produce green illumination enhancing display
contrast and enabling it to be read at night or in poor
lighting conditions. Both the BA537E and BA538E
backlights
are internally powered from the
instrument power supply so that no additional wiring
or intrinsically safe interface is required, but the
instrument supply current increases.
Current consumption
BA537E BA538E
Without backlight 10.0mA 10.0mA
Addition for backlight 22.5mA 16.0mA
Addition with terminals 3 & 4 linked 6.0mA 6.0mA
_______ ______
Total current 38.5mA 32.0mA
9.4 Alarms
The BA537E and BA538E can be supplied with
factory fitted dual solid state single pole alarm
outputs that may be independently programmed as
high or low, rate or total alarms with normally open
or normally closed outputs. Only one output option
can be fitted to a BA537E.
Configurable functions for each alarm include
adjustable setpoint, alarm delay time and alarm
silence time.
Hysteresis may be applied to rate
alarms.
CAUTION
Alarm outputs should not be used for
critical safety applications such as a shut
down system.
When the BA537E or BA538E power supply is
turned off or disconnected, alarm outputs will open
irrespective of whether normally open or normally
closed outputs have been selected.
When
designing a system an open output should therefore
be chosen for the alarm condition.
Alarm annunciators on the instrument display
indicate the status of each alarm. If an alarm delay
or silence time has been selected the annunciator
will flash during the delay or silence period.
The BA537E and BA538E internal counters are up-
dated and compared with the alarm setpoint twice
per second, irrespective of the display update time
selected. This may result in an alarm being delayed
for up to half a second after the rate or total has
exceeded the setpoint.
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