Measurement - WatchGas NEO User Manual

Press the Right key to select Gas Library, or Custom Gases. Press the Up key or Mode key
to scroll through the gas list. For high-speed scrolling, press and hold the Up key until
the desired gas name is reached. Press the Right key to select the gas and the Left key
to save and exit.
5.4.8 SET SPAN VALUE
Span value settings (including Span 2) should match the concentration(s) of standard gas.
Check to ensure that the unit of concentration (e.g., ppm or mg/m3) on the gas cylinder
agrees with the instrument setting.
5.4.9 3-POINT CALIBRATION
Normally a 2-point calibration gives adequate linearity in
PID response, but a 3-point calibration (Zero, Span 1 and
Span 2) can be enabled for more accuracy, particularly in
the high concentration range above about 500 ppm where
response is less linear. Use the Right key to enter 3-Point Cal,
then Up or Mode to scroll to On or Off, Right to select, and Left
to save and exit.
Below is the list of default 1st and 2nd Span points when using isobutylene for calibration.
These settings can be changed in the Calibration menu.
NEO MODEL
MP181
MP182
MP184
MP185
MP186

5.5 MEASUREMENT

The sub-menus for Measurement are Measurement Unit and Measurement Gas.
5.5.1 MEASUREMENT UNIT
Standard available measurement units include:
SPAN
100 ppm
100 ppm
10 ppm
10 ppm
5 ppm (benzene)
SPAN 2
1000 ppm
5000 ppm
1000 ppm
1000 ppm
N/A
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