Thermo 42i - Gas Units; No, no

Operation
Range Menu
3-14 Model 42i Low Source Instruction Manual Thermo Electron Corporation
Gas Units The Gas Units screen defines how the NO, NO
2
, and NO
x
concentration
readings are expressed. Gas units of parts per billion (ppb), parts per million
(ppm), micrograms per cubic meter (µg/m
3
), or milligrams per cubic meter
(mg/m
3
) are available. The µg/m
3
and mg/m
3
gas concentration modes are
calculated using a standard pressure of 760 mmHg and a standard
temperature of 20 °C.
When switching the selected units from ppb or ppm to µg/m
3
or mg/m
3
,
the analog ranges all default to the highest range in that mode. For example,
when switching from mg/m
3
to ppm, all the ranges default to 100 ppm.
Therefore, whenever you change units, you should also check the range
settings.
• In the Main Menu, choose Range > Gas Units.
•Use and to scroll through a list of choices.
• Press to save the new units.
Note If the units change from ppb/ppm to µg/m
3
/mg/m
3
or vice-versa, the
instrument should be recalculated, particularly if the user’s standard
temperature is different from 20 °C. A display warning will appear that
ranges will be defaulted and calibration parameters reset. 
NO, NO
2
, and NO
x
Ranges The NO, NO
2
, and NO
x
Ranges define the concentration range of the
analog outputs. For example, an NO
2
range of 0–200 ppb restricts the NO
2
analog output to concentrations between 0 and 200 ppb.
The display shows the current NO, NO
2
, or NO
x
range. The next line of
the display is used to change the range. The range screen is similar for the
single, dual, and auto range modes. The only difference between the screens
are the words “High” and “Low” to indicate which range is displayed. The
example below shows the NO range screen in single mode. For more
GAS UNITS:
CURRENTLY: PPB
SET TO: UG/M3 ?
AND SET RANGES AND CAL TOX
DEFAULT SETTINGSXXXXXXXXXX
©ª CHANGE VALUE  SAVE
RANGE AVG DIAGS ALARM