Hach Ultra MET ONE 237AB, User Manual

Page: 32 / 57

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Section 7 Troubleshooting Procedures
7.1 Common problems
7.2 Reset the counter
The counter is reset to correct any intermittent fault conditions in the microprocessor
controller functions. It is similar to restarting the computer and all the settings return to
factory defaults clearing the Memory buffer. If the particle counter does not function
properly (for example, incorrect date and time), clear the counter memory and restart the
microprocessor.
To reset the counter:
1. Turn off the Power to the counter.
2. Press and hold the
MODE
key while turning on the power. Release the MODE keys
when the counter beeps once.
3. The 3-digit display shows dEF and the 7-digit display shows 270-ic, the number and
revision level of EPROM .
4. The display may show a different revision level depending on the EPROM.
5. Press the
DOWN
arrow key to restore normal operation and program the counter
operating parameters as required.
Table 3 Trouble shooting procedures
Message displayed on the LCD Description User action
LO BATT
Indicates that the
battery requires
recharging.
1 Turn off the counter and attach the AC adapter/charger to
the power input jack at the bottom of the counter.
2 Place the counter on the stand or on any stable surface and
charge for 10–12 hours.
SENSOR
The primary cause of
this condition is sensor
contamination.
Indicates that the
internal particle sensor
is no longer operating
within acceptable limits
and any count data
taken during this alarm
condition should be
disregarded as
inaccurate.
When this alarm occurs:
1 Purge the sensor by attaching the purge filter (refer to
Figure 3 on page 9 , item 3) that is supplied with the counter
to the sensor inlet on top of the counter.
2 Place the counter on the stand and attach the AC
adapter/charger to the power connection at the bottom of
the counter.
3 Set the counter to Automatic mode and the number of
cycles to infinite (inf).
4 Press RUN and observe the particle count display. If the
count totals are high but descending, allow the counter to
operate continuously for an extended period of time until
the counts stabilize at or near zero. If the Sensor Fail alarm
persists or if the counts do not reach zero after an extended
period of time, clean the sensor (refer to
section 6.2 on
page 25 ).
LIMIT
Indicates that the
particle counts have
exceeded the
programmed limits, but
does not indicate a
failure in the counter.
Make sure that the alarm limits are set to an appropriate level
for the environment being monitored.