Detecting Gas - Crowcon Gas-Tec Manual Del Usuario

Gas-Tec

3.3 Detecting gas

1 . Now the Gas-Tec is ready for use . Place the probe towards the suspected leak or to the survey area
and view the display for read-out information . Alternatively attach the Gas-Tec to a Trigger survey unit
to use it in a moving vehicle .
2 . Gas-Tec continuously records data relating the gas reading to a log which is
stored in the internal non-volatile memory . (For further details, see section
VI .)
The Gas-Tec includes a GPS location monitor . Make sure the antenna
is not obstructed and monitor the GPS icon on the LCD display for 'lock'
information .
Depending on the coverage in the area, it can take from 30 seconds to 8
minutes for the antenna to lock on to a sufficient number of satellites .
At this point, the GPS icon at the top of the LCD display will register a lock
(see Sections VI .3 and VI .4 for further information) .
Providing the GPS is locked on to satellites, details of the instrument's
location will be written to the log .
If using the Gas-Tec for invehicle surveys, it is recommended that a 'lock' is
achieved outside of the vehicle before installation to the Trigger survey unit
(see Section VIII .2) takes place .
3 . The Gas-Tec monitors the level of hydrocarbon in the sample . The number on the screen shows the
concentration of hydrocarbon gas in parts per million (ppm) .
Press the 'Info' button to bring up a choice offering opportunities to change options on the volume of the
alarm signal, and the nature of the display . Pressing the 'DISP' button will take you to the screen of the
'Format Menu' shown in section V .1 . Choosing the 'GPS' option will display GPS data such as longitude,
latitude, and number of satellites locked onto . The screen you will reach is illustrated in Section VI .3 .
Users have the option of three display formats . All offer ppm
numerical readings, with options for moving bar or cityscape,
and a screen showing all three . Gas-Tec offers a choice of
three ranges 0-100 ppm, 0-1000 ppm and 0-10,000 ppm . The
range chosen is indicated just above the graphical output . (See
section V for instructions on how to change between these
options) .
Please note that whilst the Gas Tec V will respond to gas and
give a relative reading immediately the displayed reading may
not be sufficiently accurate for surveys requiring absolute val-
ues until the FID has warmed up and stabilised . This may take
approximately 15 minutes depending on environmental conditions .
If the screen shows
a negative value
for the gas reading,
perform a manual
zero . Press the
button by the 'INFO'
string . Choose the
'ZERO' option and
zero the machine
manually .
Operation
The Gas-Tec in use
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