Thermo Scientific Omni FTIR Multi Gas CEMS Instruction Manual page 239

Thermo Fisher Scientific
directory of "c:\Backgrounds\bkg.spa". The method is stored in the
directory of "c:\method\". All these settings are supposed to be set and
tested by the manufacturer before shipment to the user.
Adjust detector gain and mirror velocity
●
In general, if the IR source intensity "Vmax" drops below 1.5 volts, it is
time to consider adjusting of detector gain value. The gain setting is
accessed by clicking the button "bench", as indicated.
The gain value is selected using the pull down menu. Another approach to
boost the IR source intensity is to adjust the velocity of the interferometer
moving mirror. As indicated (right menu panel), the mirror velocity is also
selected using the pull down menu.
Change of HCl zero offset
●
To monitor sticky gas such as HCl and NH3 from stack gas, the system
zero offset needs to be determined by daily zero cal results, and be
subtracted from raw data, either using PLC or via script. By default, a zero
offset of 0.25 ppm is applied in the script setting for HCl measurement. If
the users need to make an adjustment, click the "Calculating Setting"
block, right below the "Collect EZ" setting block. Its setting subpanel pops
up, as shown.
IMACC Script Setting
Omni FTIR Multi Gas CEMS Instruction Manual
CEMS_SampleMode
E-5