E6 41 DTR.APC.APR.ALW.03(ENG)
9.4. Earthing
The transmitters are fitted with internal and external earth terminals.
10. SETTING AND REGULATION
APC..., APR... transmitters are factory calibrated to the range stated in the order or to the basic range.
After installation, the transmitter’s zero-point may move and require adjustment.
This applies particularly in cases where the measurement range is small, where the impulse lines are filled with
a separating liquid or where APC..., APR... transmitters are used with remote diaphragm seals.
10.1. Transmitter Range, Basic Range. Definitions
10.1.1. The maximum range of pressure, or differential pressure, which the transmitter can measure, is called
the “basic range” (for specifications of basic ranges see section 5.2.1, 5.3.1, 5.3.2, 5.4.1, 5.5.1).
The width of the basic range is the difference between the upper and lower limits of the basic range.
The internal characteristic conversion curve for the basic range is coded in the transmitter’s memory.
This is the reference curve used when making any adjustments which affect the transmitter’s output signal.
10.1.2. When the transmitter is in use the term “set range” is used. The set range is the range whose lower
end-point corresponds to an output current of 4mA and whose upper end-point corresponds to a current of
20mA (or 20mA and 4mA respectively when the conversion curve is inverted).
The set range may cover the whole of the basic range or only a part of it.
The width of the set range is the difference between its upper and lower end-points.
The transmitter may be set to any range within the basic range of pressure values, subject to the restrictions set
out in the table in section 5.2.1, 5.3.1, 5.3.2, 5.4.1, and 5.5.1.
10.2. Configuration and Calibration
10.2.1. The transmitter has features which enable metrological and identification parameters to be set and
altered. The configurable metrological parameters affecting the transmitter’s output current include
the following:
a) unit in which the measured pressure is expressed on the display;
b) upper end-point of the set range;
c) lower end-point of the set range;
d) time constant;
e) type of characteristic curve: linear or radical.
Parameters of an informational nature which cannot be altered include the following:
f) upper limit of the basic range;
g) lower limit of the basic range;
h) minimum range.
10.2.2. Other identification parameters, not affecting the output signal, include: device address, device type
code, factory identification code, factory device code, number of preambles (3÷20), UCS, TSD, program
version, electronics version, flags, serial number, label tag, description tag, date tag, message, record number,
sensing module number.
The process of setting the parameters listed in 10.2.1 and 10.2.2 is called “Configuration”.
10.2.3. It is possible to carry out a “pressure zeroing” procedure, for example to compensate for
measurement deviation caused by a change in position during the transmitter installation.
The transmitter may also be calibrated, by taking readings with the input pressure controlled using a standard
device. These process and zero-point adjustments are called “Calibration”.
10.2.4. Configuration and Calibration of the transmitter are carried out using an Aplisens KAP communicator,
certain HART communicators or a PC with HART/RS232 converter and Aplisens “Raport 2” software.
Together with the “Raport 2” configuration software there is „INTERVAL LINEARIZATION” software supplied to
enable the input of 21-point nonlinear functional characteristics to the transmitter.
A description of the functions of the KAP communicator is contained in the KAP Communicator Operating
Manual, and information on the HART/RS232 converter or HART/USB converter can be found on the converter
user manual.
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