9
the dust filter–water stop opening to the point where the line connects to the pump's inlet. Ensure
sample-line length does not exceed the pump's maximum draw.
Before and after each air sample, perform a test of the full sampling line.
o
Use a thumb to block the end of the sampling line at the water-stop opening. This should
cause a pump-fault alarm.
o
Remove the thumb from the water-stop opening. After the alarm cycle completes, the pump
should resume normal operation.
Note:
If a pump fault does
not
occur, check and correct for cracks or other damage, debris, and proper installation in
these areas: the sampling line and its connections, the pump's inlet cap and inlet barrel, and the dust filter-water stop
items at the end of the sampling line and inside the pump inlet barrel.
Based on sample-line length, calculate the
minimum time
recommended for the air sample to reach the
instrument's sensors. As shown below, use a base time of 2 minutes, and add 2 seconds for each 30
cm (1 ') of line length. Watch the display screen for gas readings and, if present, allow them to stabilize
to determine the reading.
Table 1.5 Minimum sample time for common sample-line lengths
Sample-line length
Base time
(minutes)
+
Sample-line-length
factor
=
Minimum sample time
(mm:ss)
3.05 m (10 ')
2 min
+
(10 ' x 2 s)
=
02:20
6.10 m (20 ')
2 min
+
(20 ' x 2 s)
=
02:40
9.14 m (30 ')
2 min
+
(30 ' x 2 s)
=
03:00
12.10 m (40 ')
2 min
+
(40 ' x 2 s)
=
03:20
15.24 m (50 ')
2 min
+
(50 ' x 2 s)
=
03:40
18.29 m (60 ')
2 min
+
(60 ' x 2 s)
=
04:00
21.34 m (70 ')
2 min
+
(70 ' x 2 s)
=
04:20
24.38 m (80 ')
2 min
+
(80 ' x 2 s)
=
04:40
27.43 m (90 ')
2 min
+
(90 ' x 2 s)
=
05:00
30.48 m (100 ')
2 min
+
(100 ' x 2 s)
=
05:20
Cold-weather Operation
Use caution when operating the instrument in temperatures below -20 °C (-4 °F), which can diminish
display-screen legibility and man-down functionality. To help support functionality and available battery
power, the following practices are recommended.
Do not operate the instrument in temperatures that are not within the temperature ranges of the
installed sensors (see "Table 2.6, Sensor specifications").
Use a compatible, fully charged extended range battery.
Before using the instrument in the cold-weather environment, power it on a warm-up environment
(approximately 20 °C [68 °F]).
Alternately operate the instrument in the cold-weather and warm-up environments.
Do not operate the instrument unmanned.