fafnir HART TORRIX, Техническая документация инструкция

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Adjustment Page 14/37
6 Adjustment
Versions that support the HART ® protocol enable the adjustment described
below to be carried out remotely without the probe head having to be
opened.
6.1 Measuring span at the level sensor
To enable configuration of the 4 mA and 20 mA points at the TORRIX level sensor, two
buttons and an LED (light emitting diode) are provided near the terminals inside the probe
head.
By default, the level sensor is set to maximum measuring span with 4 mA at the sensor
base and 20 mA at the probe head. The measuring span is configurable for adaptation to
the tank concerned. However, a minimum clearance of 10 mm must be observed.
If this minimum clearance is not observed, the display direction of the level sensor will be
reversed automatically (ullage measurement).
Through configuration, it is also possible to have the measured value output inverted: e.g.
the level sensor can be set to maximum measuring span with 4 mA at the probe head and
20 mA at the sensor base.
Figure 11: Adjustment of the measuring span
(1) Unscrew probe head cap (1) using an open-ended spanner.
(2) Press and hold 4 mA button (2) or 20 mA button (3) for at least 3 seconds. The
green LED begins to flash.
(3) The level sensor is now in configuration mode. The current consumption of the
level sensor is 12 mA. If no button is pressed again, the level sensor remains in
configuration mode for 20 seconds before reverting to measuring mode and dis-
carding any changes. In configuration mode, the 4 mA or 20 mA reference point,
or both, can be modified in any order.
To define a reference point:
(4) Move the float to the desired reference point and
1
+
4 mA 20 mA
–
3
4
Cal/Err
2