horiba LO-300, Instruction Manual

Page: 70 / 81

Troubleshooting
56
Troubleshooting
Countermeasure at system error

When any abnormality occurs on the detector, system error shown in Table 9 is displayed
on the monitor screen of the instrument.
Check the displayed contents of the system error, and take a corresponding action.

For the contact output at system error, refer to “ Contact output ” (page 6).

When system error due to instrument error occurs, remove the cause and restart the
detector.
Other errors automatically restore the instrument as the cause is removed.
Table 9 Correspondence methods when system error occurs
Message History Error Main cause Correspondence method
LOW LEVEL LOW
Detection level
error (Detection
area error)
Lower limit error judgment
threshold is set to high (near the
water level of detection area) Set the lower limit error judgment
threshold to a low value to the water level
of detection area (such as 4 mA).
Suspended objects of low
reflectivity such as paper, wood
piece, or grass accumulate on the
detection area, disabling to
receive laser light.
Remove suspended objects from the
detection area.
Monitoring surface has water
shortage (or runout of water),
disabling to receive laser light.

When the water level is detected, the
LOW LEVEL indication automatically
disappears, returning to a normal
state.

When the LOW LEVEL indication is
not required, set the low limit error
judgment to invalid.
Ripples on the monitoring surface
is large due to influence of rain or
wind, or fast flow rate of water
channel, disabling to receive
laser light.
Take actions as follows according to the
cause or conditions:

Move to a place with little influence by
rain or wind.

Provide a lid to a monitoring water
channel to avoid influence by rain or
wind.

Provide a rectifying plate (baffle plate)
in the monitoring water channel to
decrease ripples.
Fog, vapor, steam filled between
the detector and the detection
area are diffused, disabling to
receive the laser light.
Take actions as follows according to the
cause or conditions:

Move to a place with little vapor or
steam.

Attach a steam protection hood
optionally available to perform air
purge.
Severe dirt or blur of the optical
window disables to receive the
laser light. Using a cloth with water and wrung out or
a glass cleaner, wipe off the dirt on the
optical window.
Loosening of fixing or slant of
cabinet disables to receive the
laser light.
Place an attached round level on the
upper lid of the detector or on the upper
part of display box, to adjust the detector
to horizontal.