MAC MAC155H, Instruction Manual

Page: 59 / 143

©Copyright MAC Instruments 2005. All Rights Reserved. MAC155 Rev. 12
Pg 43
TROUBLE SHOOTING
Before performing any Troubleshooting procedure, study the manual
until the procedure is understood. If there is any confusion or doubt,
contact the factory for further assistance.
Only trained personnel familiar with this type of equipment and the
hazards involved should attempt maintenance. There is a danger of
severe burns from hot surfaces and electrical shock or electrocution
from dangerous electrical voltages.
The MAC155 Probe is actually two instruments integrated together. The
main purpose of the instrument is to put out an electrical signal that is
proportional to the percentage water vapor by volume in a sample that is drawn
from the atmosphere that is being monitored. This can be thought of as the
“Moisture Analyzer”. Additional equipment in the MAC155 Probe is there only for
checking the calibration of the “Moisture Analyzer”. The equipment that is used
to check the calibration can be thought of as the “Calibrator”.
The “Moisture Analyzer” and the “Calibrator” share certain hardware in the
MAC155 Probe. The same power supply is used, and a single processor
operates each part of the instrument. The main circuit board contains circuitry
for both of the functions.
When trouble shooting the MAC155 Probe, it is important to keep in mind if
you are working on the analyzer or the calibrator.
Analyzer Hardware Shared Hardware Calibrator Hardware
Extension Tube Power Supply (in controller) Condenser
Filter Main Board Water Tank
Barrel Heater Barrel Calibration Valve
Range Module Calibration Pump
Sampling Pump
Potential problems can be roughly classified as mechanical or electrical in
nature. Appropriate test equipment is required for each type of troubleshooting.