Teledyne 7120 - NDIR analyzer - Manual (Page 74)

Infrared Analyzer Maintenance 5
5-7 Teledyne Analytical Instruments
5.6 Troubleshooting
5.7 General
This section contains information on the assembly and the electronic sections
of the Model 7100 Infrared Analyzer. The sample-handling sections of the
system are statistically low failure items and only require the maintenance as
pertinent to sample system operation (plugging, flowrates, leaks, etc.). Flow
system “failures” are usually of the nature that are easily resolved by
personnel familiar with basic mechanics of the Model 7100 flow system or
sample system.
The electronic sections are more complex, requiring the assistance of
personnel trained in electronics in the event of failure. The electronics
sections of the analyzers include advanced solid-state and digital circuitry
which requires a thorough understanding of circuit theory and
troubleshooting techniques.
NOTE
It is recommended that only qualified electronic technicians
troubleshoot electronic failures within the analyzers. Although
both analyzers contain plug-in printed circuit panels, service
personnel should be familiar both with the analyzer theory of
operation and the basics of analog circuit theory before
troubleshooting.
All basic customer electronic adjustments and calibrations of the analyzer
can be accomplished with a DC volt-ohm meter (preferably with a digital
readout). The analyzer contains AC waveforms which, only for failure-
troubleshooting purposes, may be monitored by a medium bandwidth
oscilloscope. All circuit boards are of the plug-in replaceable type and only
require a DC voltmeter for set-up.
The following is a listing of parts needed for electronic calibration and
troubleshooting of the analyzers:
Accurate DC volt-ohm meter (digital readout) with clip-type leads
Single-trace medium band width oscilloscope
15Äpin extender card (TAI P/N 9881)
Miniature clip-type jumper leads (12" long)
Small blade screwdriver (TAI P/N S-190)