Heath Consultants GT Series - Manual (Page 80)

7-4
USER HANDBOOK
7.4.1 CO Direct
In this option, normal atmospheric air is checked for CO
content.
The typical display for this mode is shown in Fig. 7.3:
Fig. 7.3 CO Direct
7.4.2 Differential CO
This option enables the user to zero out ambient CO
backgrounds and display the differential measurement.
This is useful in areas where the ambient CO is high from
other sources such as traffic pollution.
The typical display for this option is shown in Fig. 7.4
Fig. 7.4 Differential CO
To zero the displayed CO reading:
• Press and hold ZERO .