gefran TKDA series User manual

INDUSTRIAL PRESSURE TRANSMITTER
TKDA/TPSADA series
OPERATING MANUAL
DIGITAL AUTOZERO & SPAN OPTION
code 85189 ed. 01 - 01/07
This section contains information and warnings of a
general nature which should be read before proceeding
with any function activation
The transmitter remains on the std operating mode, till an
external event happens.
The possible channels to activate the additional functions
are the following:
- CAL pin
- Magnetic pen
The operating manual explains the following features:
1) Autozero
2) Fine-Autozero
3) Calibration
4) Autospan
5) Partial Reset
6) Total Reset
CAL pin: activation of CAL function (Calibration, Autospan)
is made by closing the contact between the following pin:
• 6 pole connector version (V) pin E-F
• 7 pole connector version (P) pin 5-6
The following pages explain the application modality, for all
the additional functions.
The contents are related to application limits and aims.
1) AUTOZERO
Application mode Limits Result
The Autozero function is activated by :
1) positioning the magnet near the
Autozero label on the shell of the
sensor.
The magnet has to be maintained on
the Autozero position for a time within
1 to 10 sec.
The whole Zero unbalancement in
addition to the zero done by the
manufacturer, has to be within ± 10%
FS.
The Autozero effect will be visible
after waiting 2 sec from the release of
the magnetic pen.
The precision of the zero value will be
within the accuracy class of the sen-
sor.
The Autozero function doesn’t work
outside the defined limits.
NOTE:
During the Autozero phase, the output for current transmitter series, will increase around 7mA.
That’s a short variation only visible during the Autozero phase; it won’t have any effects on the final result.
Figure 1 : represents the “magnetic pen"
Figure 2 : represent the Autozero function label
on the sensor housing
Figure 3 : shows the position of the pen on the
shell while activating the autozero
function
Figure 1 Figure 2 Figure 3
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2) FINE-AUTOZERO FUNCTION
Application mode Limits Result
The Fine-Autozero function is activa-
ted by :
1) positioning the magnet near the
Autozero label on the shell of the
sensor.
2) The magnet has to be maintained
on the Autozero position for a time
within 10 to 30 sec.
After removing the magnet the
signal will start changing the value
step by step.
Stop adjustment:
Touch the Autozero area with the
magnet to stop the signal scrolling.
The whole Zero unbalancement in
addition to the zero done by the
manufacturer, has to be within
± 10%FS
The output signal will change within a
± 100mV value (± 0.16mA for 4 to
20mA output) in steps of 6mV ( 12µA
for 4 to 20mA output).
Eg:
0..-6..-12..//-100..+100..+94..+88..0
When the desired zero value is rea-
ched stop the adjustment cycle by
touching the Autozero area with the
magnet.
The Fine-Autozero function doesn’t
work outside the defined limits.
NOTE:
- The step duration time is 5 sec
- During the Autozero phase, the output for current transmitter series, will increase to around 7mA.
Furthermore between the step variations it will be possible to have short overcurrent up to 7mA.
- That’s an immediate variation only visible during the Autozero phase; it won’t have any effects on the final result.
- The new zero value setted with the “Fine-Autozero” function, will be the zero reference for future “Autozero” procedures.
3) CALIBRATION
Application mode Limits Result
Start calibration
The Calibration function is
activated by short-circuiting the
CAL pin for a minimum time of
1 sec
Stop calibration
Release the CAL pin short-circuit
The whole Zero unbalancement in
addition to the zero done by the
manufacturer, has to be within
± 20%FS.
During the Calibration phase the
signal will be unbalanced at 80% FS.
The calibration effect is visible 2 sec
after short-circuiting CAL pin.
The Calibration function doesn’t work
outside the defined limits.
NOTE:
- Switching off the supply while the calibration function is activated, could be cause of calibration problems; the
transmitter can be restored to the initial value by activating the “partial reset function”.
- To locate the CAL pin contacts, please refer to item “CAL pin” at the beginning of this manual.
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4) AUTOSPAN
Application mode Limits Result
The Autospan function is activated in
three steps as explained in the
following.
Phase 1) pressure = 0 bar:
1° Autozero
Activate the Autozero function
Phase 2) pressure = FS ***:
Short-circuit CAL pin.
Maintain the short-circuit,
after a minimum time of 1 sec.,
start the “Autozero function”; the
magnet has to be maintained in
contact for a period of 1 - 10sec.
Than release the short-circuit,
after a minimum time of 1 sec.
Phase 3) pressure = 0 bar:
2° Autozero
Activate the Autozero function
The whole Zero unbalancement in
addition to the zero done by the
manufacturer, has to be within
± 10%FS
The whole span unbalancement
which can be obtained must be within
± 5% of the FS of the transmitter
The transmitter will be calibrated at
the new Zero and Span values, within
the accuracy class of the sensor.**
The Autozero function doesn’t work
outside the defined limits.
NOTE:
**: It is possible improve the calibration precision by doing several calibration runs (Autospan function).
***: The FS has to be a pressure value within ± 5 %FS
- To locate the CAL pin contacts, please refer to item “CAL pin” at the beginning of this manual.
5) PARTIAL RESET OF THE CALIBRATION VALUES
Application mode Limits Result
The partial reset function is activated
by positioning the magnet near the
Autozero label on the shell of the
sensor.
The magnet has to be maintained on
the Autozero position for a time within
30 to 60 sec.
The Zero of the transmitter will be
restored to the factory settings; fur-
thermore an Autozero will be done
automatically.
The Span calibration will not be affec-
ted.
NOTE:
- During the partial reset phase, the output for current transmitter series, will increase around 7mA
6) TOTAL RESET OF THE CALIBRATION VALUES
Application mode Limits Result
The total reset function is activated by
positioning the magnet near the
Autozero label on the shell of the
sensor.
The magnet has to be maintained on
the Autozero position for a time over
60 sec
The Zero and Span of the transmitter
will be restored to the factory
settings.
NOTE:
- During the total reset phase, the output for current transmitter series, will increase around 7mA
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