User Manual
3200 Series
42 Part No HA028651 Issue 11.0 July-12
8.2
PV Offset
All ranges of the controller have been calibrated against
traceable reference standards. This means that if the
input type is changed it is not necessary to calibrate the
controller. There may be occasions, however, when you
wish to apply an offset to the standard calibration to
take account of known errors within the process, for
example, a known sensor error or a known error due to
the positioning of the sensor. In these instances it is not
advisable to change the reference (factory) calibration,
but to apply a user defined offset.
PV Offset applies a single offset to the temperature or
process value over the full display range of the controller
and can be adjusted in Level 3. It has the effect of
moving the curve up a down about a central point as
shown in the example below:-
8.2.1
Example: To Apply an Offset:-
Connect the input of the controller to the source device
which you wish to calibrate to
Set the source to the desired calibration value
The controller will display the current measurement of
the value
If the display is correct, the controller is correctly
calibrated and no further action is necessary. If you wish
to offset the reading:-
Do This
Display
Additional Notes
1.
Select Level 3
or Conf as described
in section 6.1.3. Then
press
to select
‘INPUT’
Scrolling display
‘
p ro c e s s
in p u t l is t
’
2.
Press
to
scroll to ‘PV/OFS’
3.
Press
▲
or
▼
to adjust the
offset to the reading
you require
Scrolling display ‘
p v
o f fs e t
’
In this case an offset
of 2.0 units is applied
It is also possible to apply a two point offset which
adjusts both low and high points. This is done in Level 3
using the CAL List, and the procedure is described in the
Calibration section 16.
8.3
PV Input Scaling
Input scaling applies to the linear mV input range only.
This is set by configuring the INPUT TYPE parameter to
mV and has an input range of –10 to 80mV. Using an
external burden resistor of 2.49
Ω
, the controller can be
made to accept 4-20mA from a current source. Scaling
of the input will match the displayed reading to the
electrical input levels from the transducer. PV input
scaling can only be adjusted in Configuration level and is
not provided for direct thermocouple or RTD inputs.
The graph below shows an example of input scaling,
where it is required to display 2.0 when the input is 4mV
and 500.0 when the input is 20mV .
If the input e5% of the mV.Lo or mV.Hi settings,
sensor break will be displayed.
8.3.1
Example: To Scale a Linear Input
Select Configuration level as described in section 6.1.3.
Then:-
Do This
Display
Additional Notes
1.
Then press
to select ‘INPUT’
Scrolling
display
‘
p ro c e s s in p u t
l is t
’
2.
Press
to
scroll to ‘IN.TYP’
3.
Press
▲
or
▼
to ‘mV’
Scrolling
display
‘
in p u t ty p e
’
4.
Press
to
scroll to ‘MV.HI’
5.
Press
▲
or
▼
to ’20.00’
Scrolling
display
‘
l in e a r in p u t
h ig h
’
6.
Press
to
scroll to ‘MV.LO’
7.
Press
▲
or
▼
to ‘4.00’
Scrolling
display
‘
l in e a r in p u t
lo w
’
8.
Press
to
scroll to ‘RHG.HI’
9.
Press
▲
or
▼
to ‘500.0’
In operator level the
controller will read
500.0 for a mV input of
20.00
10.
Press
to
scroll to ‘RNG.LO’
11.
Press
▲
or
▼
to ‘2.0’
In operator level the
controller will read 2.0
for a mV input of 4.00
in p u t
Electrical Input
Display
Reading
Fixed offset
(e.g. 2)
Factory
calibration
2.0
pv.o fs
mv
in . ty p
20.00
m v. h i
500.0
rh g. h i
4.00
m v. lo
2.0
rh g. lo
For mA inputs
4-20mA = 9.96-49.8mV with
2.49
Ω
load resistor
0-20mA = 0-49.8mV with
2.49
Ω
load resistor
mA input will detect sensor
break if mA < 3mA
Use a current source to
remove shunt resistor errors
m v. lo
eg 4 mV
Electrical Input
Display
Reading
R N G . H I
eg 500.0
R n g . lo
eg 2.0
m v. h i
eg 20 mV
Summary of Contents for XST-2-0-12-1V1-E28
Page 16: ...12 FURNACE TROUBLE SHOOTING ...
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Page 31: ...3216 3208 3204 User Manual 3200 Range Process Controller HA028651 11 Aug 2012 ...
Page 170: ...User Manual 3200 Series 138 Part No HA028651 Issue 11 0 July 12 21 Certificate of Conformity ...
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Page 173: ...Model 2416 Process Controller User Manual Part No HA025041_12 Date August 2014 ...
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