1.2 Description of product components
1.2.1 Measuring heads
Sensor’s measuring head (fig. 1.2) contains:
- capacitometer;
- inclinometer (in certain models);
- data concentrator with calibration tables;
- digital data processing circuit;
- data exchange device;
- galvanic barrier (for model EN);
- power stabilizer and scheme providing necessary protection of input
and output circuits.
Connection with external devices is provided through interface cable.
Capacitometer performs the conversion of current capacity of the probe
into digital code. Conversion is a linear function with variable parameters.
Inclinometer is present in the models of EXХXiх-XXXX version. Inclinometer
is executed on the basis of accelerometer with high resolution, and designed for
evaluation of acceleration and inclination angle of the vehicle, in order to estimate
reliability of the fuel level value and for possibility of its consequent compensation
depending on inclination angle.
Built-in data concentrator features in all listed models, however, using it
together with other sensors is possible only with EN6 model due to the presence
of two independent interfaces RS-232 and RS-485. Designation of master and
slave ports is set programmatically. Other models may only use embedded
calibration tables on the eigenvalues.
Digital data processing circuit performs control of capacitance meter (range,
zero offset, etc.) as well as temperature compensation, filtering and scaling the
obtained data. Data exchange device allows data exchange with the monitoring
device, saving / loading of calibration and configuration data of fuel level sensor,
remote upgrade of built-in software via serial interface.
Built-in galvanic isolation is an additional instrument fuel level sensor safety
system, and it is designed for isolation of measuring element’s and probe’s circuits
from the rest of electronics of the head.
This solution eliminates the possibility of passage interference currents on
circuits "case – signal ground”, increases interference immunity of measuring
element, enhances stability and reliability of the entire device.
For EZ model galvanic barrier is realized in spark protection module BIZ-EZ.
The measuring head is attached to the probe by means of a threaded
connection. Tightness of measuring head's attachment is provided by sealing ring
located in the end groove.
1.2.2 Probe