12
Step 6
With 20.000mA input current adjust the
span potentiometer until the indicator
displays 140.0
Step 7
Repeat steps 5 and 6 until both
calibration points are correct.
8.3 Display backlight
The BA304NC can be supplied with LED
backlighting to improve display contrast in poorly
illuminated areas. This backlight is electrically
segregated from the measuring circuit and has
been certified as a separate Ex nL Group II,
Category 3G circuit.
The Type n input safety parameters ae:
Ui
= 30V dc
Ii
= 100mA
Pi
= 1.3W
This allows the backlight to be powered from a
safe area 18 to 30V dc supply as shown in Fig 8.
Providing the supply voltage is less than 30V dc in
normal operation the backlight safety components
will ensure that the maximum input current and
power are within the safety limits.
Fig 8 Separately powered backlight
Reducing the supply voltage below 18V will reduce
the backlight brilliance.
8.4 Pipe mounting kits
Two pipe mounting kits are available for securing
the BA304NC to a horizontal or vertical pipe.
BA392C Stainless steel bracket secured by two
worm drive hose clips. For 60 to 80mm
outside diameter pipes.
BA393
Heavy duty stainless steel bracket
secured by a single 'V' bolt. Will clamp
to any pipe with an outside diameter
between 40 and 80mm.
8.5 Panel mounting kit
The BA394 stainless steel panel mounting kit will
secure a BA304NC indicator into a panel aperture,
but it does not seal the joint between the indicator
enclosure and the instrument panel.
