Teledyne 7300a - NDIR analyzer - Manual (Page 49)

Infrared Gas Analyzer Operation 4
4-13 Teledyne Analytical Instruments
6 160
7 320
8 640
9 1280
10 2360
The response time listed above can and will change depending on the
application and they merely serve to illustrate the effect of the digital filter. The
digital filter disengages if there is an upset that is more than 5% of full scale. As
the reading comes within the range, the filter becomes active once again.
4.3.10 Zero Offset Adjustment
The software in this instrument provides a way to enter an offset on the
zero operation of the analyzer. If the background gas of the process is different
than the zero calibration gas being used, the reading will have an offset that will
be constant throughout its working range. Thus, the need to provide an offset
when the instrument is being zeroed.
How to access the offset function:
To access this function, Scroll through the menu and select OFFSET.
Press the Enter key to see the following screen:
Enter zero offset:
0.00 %
The offset value can be modified by using the Up/Down keys. Next section
shows how to select this value. Suffice to say that whatever value you enter, will
be automatically added to the reading. Thus, if you entered -0.10 %, at the end
of the zero the display will show -0.10 %.
When the instrument enters the zero mode in AUTO, the instrument will do
the work of bringing the reading back to zero plus the offset value that was
entered. If you chose MANual zero mode, then you must adjust the zero of the
instrument the corresponding section of the manual but with one difference:
instead of bringing the display to read zero, you must make the display read zero
plus the value entered as offset.