LI-COR LI-8 0 Series Manual

Replacing the Source and Detector in
the LI-8x0 Analyzers and LI-8100/A
This document describes how to replace the optical source
and detector on the LI-830, LI-850, and LI-870 gas analyzers,
legacy LI-800, LI-820, LI-840, and LI-840A gas analyzers, and
the LI-8100/A Automated Soil CO
Source Detector
LI-850 / LI- 800-902 800-918
870
LI-830 800-902 800-916
LI-840/A 800-902 800-906
LI-820 800-902 800-903
LI-800 800-902 800-903
LI-8100/A 8100-902 800-906
Contents

LI-800, LI-820, LI-830, LI-840/A, LI-850, and LI-870

Li-8100/A Source And Detector Replacement
LI-800, LI-820, LI-830, LI-840/A, LI-850,
and LI-870
The optical source and detector may need to be replaced if
one fails. The life expectancy of the source is typically
>20,000 hours, or >2 years of continuous operation, but this
will vary depending upon the number or warm-up cycles,
vibration, and other factors. Typically, detectors need to be
replaced rarely, if ever.

Disassembly

You'll need #1 or #2 Phillips screwdriver and a clippers or
utility knife. The installation, including calibration, may take
an experienced technician 30 minutes to 1 hour. If the instru-
ment has been running recently, the bench may be hot to the
touch. Let it cool for 5 or 10 minutes after powering off if
needed.
Note: Be sure that you are properly grounded to avoid elec-
trostatic discharge that can damage the electronics. Use an
anti-static wrist strap, electrostatic discharge grounding mat,
Flux System.
2
Part Numbers
14 cm 5 cm
Bench Bench
800-904 n/a
800-904 n/a
800-904 n/a
800-904 800-905
800-904 800-905
800-904 n/a
or occasionally touch bare metal that has a clear path to
ground, such as an unpainted computer case.
Power off the gas analyzer and remove the top cover
1
(LI-800, LI-820, LI-830, LI-840/A and LI-850) or open
the case (LI-870 only).
The LI-800, LI-820, LI-830, LI-840/A and LI-850 top cover
is held in place by 6 screws. Loosen the screws and lift off
the cover. If there is a ribbon cable connecting the top
panel, be careful not to strain it. The LI-870 is opened by
removing two screws that hold the case closed; then
remove four screws that secure the optical bench cover.
2 Unplug the source and detector ribbon cables from
the source and detector.
1
3
Lift the optical bench out of the foam insulation.
3

Replacing the Optical Source

With the optical bench free of the case (except the tubing),
you can remove the source from the optical bench.
1 Remove the tube from the source.
The simplest way is to cut the tubing as close to the hose
barb as possible.
2 Remove the four larger screws from the optical
source.
Installation Guide
1