Teledyne First Responder CG, User Handbook Manual, Page: 15 / 104

2-1
2
GENERAL INFORMATION
Ranges of Operation
The instrument calibration gas is shown on the instrument
service label.
EXT Range (External Semiconductor Sensor),
0 – 4,500 ppm - 20 %LEL Flammable
(TRAC mode only)
This range displays flammable gas parts per million
(ppm) content up to 4,500pmm, then autoranges to %LEL
(concentration up to 20% LEL). When this range is selected,
EXT for external, is displayed in the top right corner of the
LCD.
A ‘Geiger’ alarm provides assurance that the instrument
is sensing for gas without the need for the operator to
constantly view the display.
When the instrument is switched on, the visual Geiger
indication is operational. To activate the audible Geiger
indication, press
(Button Four). Each single press of
(Button Four) will toggle the audible Geiger indication
ON and OFF.
When the audible Geiger is activated, the display changes
between EXT and Aud, as illustrated in Figure 2-1.