SIREC D Display Recorder 7ND4000

2. Use the UP (↑) or DOWN (↓) Arrow Keys to
select 1 or 0, then press ENTER. The display returns
to "Decimal fix" in the Point Setup Menu.
E. Filter - Refer to Paragraph 4.6.5.G for
instructions on programming filter.
F. Compensation - Thermocouple
compensation can be local, from a temperature
sensor built into the Recorder, or external through a
point. When thermocouples are compensated
locally, the temperature sensor (located on the rear
terminal panel of the Recorder) measures the
ambient temperature of the cold junction. For
remote compensation, a single Thermocouple or
RTD can be used to measure the ambient
temperature of the remote junction box. This
method allows several thermocouple points to be
measured without using thermocouple extension
wire for each input. The point used as the
measurement source of the remote cold junction
source is referred to as the compensation channel.
The point used as the compensation channel must
be programmed before the Thermocouple or RTD
input is assigned to it.
1. Programming Compensation - Use the UP
(↑) or DOWN (↓) Arrow Keys to scroll through the
menu items in the Point Setup Menu and highlight
“Compensation” and press ENTER.
2. Local or Remote Compenstation - Use the
UP (↑) or DOWN (↓) Arrow Keys to highlight either
“Local comp” or “Ext comp”.
3. Local Compensation - If “Local comp” is chosen,
press ENTER and the display returns to the
“Compensation” prompt in the Point Setup Menu.
4. External Compensation - If “Ext comp” is chosen,
press ENTER and the display prompts for
“ext point? X”. Use the UP (↑) or DOWN (↓) Arrow
Keys to scroll through the point numbers to
choose the input where the external compensation
is input. When the desired point number is
displayed, press ENTER and the display returns
to the “Compensation” menu item in the Point
Setup Menu.
NOTE
A Compensation Point needs to be programmed
in degrees C (°C).
Siemens AG C79000-G7374-C211-01
SIREC D Manual
Programming
G. Span and Offset - In order for the
Span/Offset menu option to be available, you must
turn this feature on in the Measurement Program
menu, refer to Paragraph 4.8.2, Span and Offset.
Once this option has been turned ON, you can use
Span and Offset to compensate for long
thermocouple runs or thermocouple inaccuracies.
The default value for offset is 0 and the default
value for span is 1. The offset is a value of absolute
degrees which is added or subtracted to the
thermocouple reading. The span is a multiplier of
the absolute thermocouple range. Once span and
offset have been entered, the new adjusted range
will be
New T/C Range = (Full Scale * SPAN) + OFFSET
NOTE
Span is a multiplier while offset is an additive.
1. Programming - To adjust the span and offset
(this assumes this option has been turned on in
the Measurement menu) use the UP (↑) or
DOWN (↓) Arrow Keys in the Thermocouple option
menu to select Span/Offset and press
ENTER. The display will show “Ofs� 0.0000�”.
2. Offset Value - Use the numeric keys to enter a
value for the offset which will be added or subtracted
to the thermocouple value. Note that offset
is typically measured around the ice point which
should be 0° C or 32°F. The offset would be typically
the difference between the thermocouple
reading at this point and the true ice point value.
Press ENTER. The display will then show “Spn
�1.00000�”.
3. Span Value - Use the numeric keypad to enter
the new span value. The span should typically be
measured near the full scale value of the thermocouple
using a known temperature or reference.
The span would be the absolute value of the reference
divided by the reading of the thermocouple.
Press ENTER to register these values and
return to the Thermocouple option menu.
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