Merck 1.44093.0001, Operation Manual

Page: 84 / 88

84
Troubleshooting
symptom Possible Cause Corrective Action
Counts are too low • Instrument is being operated outside temperature or
relative humidity specifications.
• Internal parts have been damaged because instrument
was stored at a temperature higher than 122 °F (50 °C).
• Instrument has contamination on the optics due to
condensation or excessive loading
• Laser or pump control is damaged
• Unit is due for calibration
• Operate instrument within specifications
• Return to factory for service
• Return to factory for service
• Return to factory for service
• Return to factory for service
Instrument does
not turn on
• Battery is empty
• AC cord is not plugged into unit • Recharge battery or connect to AC power
• Connect AC power cord
Instrument does
not meet zero count
specification
(≤1 particle / 5 min) • HEPA filter is not connected properly and room air is
leaking into the HEPA filter assembly
• Residual particles from previous samples are shedding off
internal parts and into the optics
• An internal component has been damaged due to operation
outside of temperature specifications or one or more
excessive bumps or jolts, and electronic noise is inducing
false counts
• A leak has developed in the air flow path
• Internal optics have become dirty
• Check that the HEPA filter has been
tightly connected to the inlet.
• Purge instrument by running the instru-
ment for 10–15 minutes before attempting
zero count test
• Return to factory for service
• Return to factory for service
• Return to factory for service
Battery does not
charge
• The unit must be turned on but not in sampling mode
for the battery to charge
• Turn on unit.
Low Battery Error • Low battery • Recharge battery or connect AC cord
Photodetector
Error • Direct light is entering the air inlet
• Laser has become misaligned due to excessive bumps
or jolts
• Internal optics have become dirty
• Remove instrument from direct light
• Return to factory for service
• Return to factory for service
System Error • Information is not being read properly by microprocessor • Restart instrument. If problem persists,
contact Merck technical support
Temperature Humidity
Probe Error • Temperature/RH probe was not recognized • Detach and reconnect probe. If problem
persists, contact Merck technical support
Flow Error
The flow error is indicated
by the crossed flow rate
icon if the flow rate is out
of the range of +/- 5% on
the nominal flow rate • Instrument was unable to control flow rate
(if any tubing is connected to particle counter)
• Pressure drop across inlet may be too large
• Inlet not at ambient pressure
• Restart measurement
• Lessen pressure drop across inlet by using
larger diameter tubing, less tubing, and/or
adding a bleed valve
• Do not subject the unit to other than
ambient pressure conditions
Laser Power Warning • Laser power has fallen outside of specification • Return to factory for service