- 37 -
Use of the Green Keys - TRIM - Sensor Trimming - FULL TRIM
( for 600T, 600T EN and Deltapi K pressure transmitter )
A p p l y a H i V a l P r e s s.
h i g h e r t h a n L o V a l
PRO
CEED
T R I M M I NG A N D S E T U P
SNSR 4 - 20 LOOP CALI
TR I M TR I M TEST BRA
S E N S O R T R I M , S E L E CT
T Y P E
FULL ZERO STAT
TRIM TRIM TRIM
Last i nput value used
LoVal = 0 mmH2O
H i Va l = 1400.000 mmH2O
LoVal = 0 mmH2O
H i Va l = 1400.000 mmH2O
L O W H I G H D I S P
T R I M T R I M L I M I T
Lo V a l = 0 mm H2O
H i V a l = 1400.000 mm H2O
L O W H I G H D I S P
T R I M T R I M L I M I T
E n t e r a p p l i e d L o V a l
[ - 5 . 0 1 5 ] mmH2O
< - -- - - > C L R E N T R
P r e s s u r e s t a b i l i z i n g
- - - P L E A S E W A I T - - -
A p p l y a L o V a l P r e s s.
l o w e r t h a n H i V a l
PRO
CEED
L R L = - 2800.000 mmH2O
U R L = 2800.000 mmH2O
P R O
C E E D
CAUTION : remember that this procedure must be done by applying
input pressure, expecially when the choosen span is unfortunately
small (<5% of URL). If you don't apply input pressure, there will be
a permanent error in the output of the transmitter. Let us say that the
trimming operation on values <10% of URL, does not make better
instrument efforts on this span.
Starting from the top display press the F1 key ( SNSR TRIM ) : the
following display will appear.
Pressing the F1 key ( FULL TRIM ), a warning message is displayed:
"WARNING - Control loop should be in manual " and the label
PROCEED for the key F4.Pressing this key the following display
appears:
The display gives indication about the input values used during the last
trimming operation. This indication lasts for some seconds and is then
replaced by the new display below.
The same values are displayed but two labels appear for the keys F1 and
F2 , respectively LOW TRIM and HIGH TRIM, while the key F3 - DISP
LIM can be used to display the lower and upper range limits (LRL and
URL). Pressing the F1 a message is displayed asking the user to apply
the low pressure value.
If the Low Trimming value corresponds to zero and you are trimming a
transmitter other than absolute pressure, the atmospheric pressure can
be taken as reference or the bypass opened to equalize the pressure on
both side of the sensor. Care should be paid to the absolute pressure
transmitters where a vacuum reference should be used or the actual
atmospheric pressure taken into consideration. After having applied the
pressure press the F4 to PROCEED.
The value of the pressure read by the transmitter is then displayed within
square brackets : this value can differ from the value read in the
reference meter. A blinking cursor is present in the most significant digit
: using the F1, to move left, or the F2, to move right, and the numerical
keypad introduce the value read on the reference pressure meter or zero
if appropriate. When the value is correctly introduced press F4 to
ENTER the value. If the value is incorrect then one of the following
messages is issued :
- Trim span too small
- Trim on negative side not allowed (for Deltapi K transmitter)
NOTE : Do not introduce change, on the value read, of more that 5%
of the URL at once. If this limit or pressure limits are exceeded a
message will be displayed ( see the relevant section of this
manual ). The Communicator accepts the first five digits of the
input.
Small differences, of the order of the 0.003% of the URV, on the
reading, are tolerated.
The introduced value is sent to the transmitter: the usual blinking T
appears in the upper right corner of the display signalling that a
communication is on course. Right after the display at side appears
showing the modified value.
The procedure to trim the high value is the same: pressing the F2 key
the following message appears: proceed then as for low trimming.
Note: Do not attempt to apply, as Hival, a value resulting in a span
smaller than the minimum span and, for Deltapi K Pressure Tx
having a S/W Rev. up to 5.1 a negative value or a value too close to
zero. In this case the operation will abort and an error message is
displayed.
For best results perform a low trimming, a high trimming and a low
trimming again. To exit from the trimming procedure press ESCAPE :
the following display appears. Take note of it and then press PROCEED:
the display returns to the Sensor Trimming menu.
W A R N I N G - loop may be
returned to auto
PRO
CEED
