Section 2
2-4
Setup & Operation
Low Battery Voltage
IMPORTANT:
The LI-6262 has no built-in circuitry for monitoring
battery voltage. When battery voltage drops below approximately 10.5
volts, the analyzer will shut down, and data transmission will stop. It is
therefore suggested that battery voltage be monitored regularly to avoid
system shutdown.
You may wish to monitor battery voltage with an external voltmeter, or use a
timer with an alarm to alert the user to possible system shutdown. If you
intend to operate the LI-6262 with battery power for more than 3 hours with
the 6000B (6 hours with the 6200B), it is recommended that a user-supplied
battery with a larger storage capacity be connected using the battery leads
included with the LI-6262, or that several batteries be used in parallel for
longer operation.
2.3 Gelman Filter Installation
IMPORTANT:
Always install the external air filters before operating
the LI-6262.
Insert filters into
both
the SAMPLE and REFERENCE
airstreams before they enter the LI-6262.
Failure to do this will lead to
contamination of the sample and reference optical paths, which can
cause large zero offsets that may require expensive repairs.
The Gelman polypropylene filters included use PTFE filter elements with a
1
µ
m pore size. They have excellent particle retention, very low water
sorption, little flow restriction and small internal volumes. These filters will
not fit inside the LI-6262 case, and must be used externally.
In
absolute mode
, insert a filter between the scrubber tube outlet (top) and
the
REFERENCE IN
port (Figure 2-3). Use a jumper tube to connect the
REFERENCE OUT
port to the
TO CHOPPER
port. The scrubber tube inlet
(bottom) is connected to the
FROM CHOPPER
port. Air supplied to the
sample cell must also pass through a filter before it enters the LI-6262.
In
differential mode
, place a filter in the sample airstream before it enters the
SAMPLE IN
port on the LI-6262. Place a second filter in the reference
airstream before it enters the
REFERENCE IN
port.
