Hach-Lange HQD - Luminescent Dissolved Oxygen Probe LDO - Manual (Page 12)

12 DOC272.53.80021
Slope out of range
Probe not prepared for sample
Allow probe to reach equilibrium in a water-saturated air
environment and repeat calibration.
Calibration method settings
Verify that the calibration standards in the method are
correct.
Sensor cap loose, scratched or
damaged Locate and install the iButton that matches the sensor cap
and replace the sensor cap.
Temperature and pressure errors
Verify temperature and pressure are reading accurately.
Contact a Hach Technical Representative.
1
LED lights do not function Contact a Hach Technical Representative (800-227-4224)
LDO–calibration not
supported (factory
calibration)
LDO method calibration option is set to
Factory. If user calibration is desired, change settings in Cal
options. Refer to
Calibration on page 3 .
O
2
Sensor 0 days
remaining
There are 0 days remaining in the life of
the LDO sensor cap
Replace the LDO sensor cap. Calibration will be allowed,
however the calibration icon and question mark will
appear on the measurement screen even if the calibration
has passed.
Meter set to incorrect date and time
Disconnect the probe from the meter. Set the correct date
and time in the Meter Options menu. Connect the probe
and verify that the message has been removed.
Software not updated
Update the HQd software to the latest version and test
again.
O
2
Sensor ## of days
remaining
There are 30 days or fewer remaining in
the life of the LDO sensor cap.
Replace the LDO sensor cap soon.
Calibration failed:
outside of acceptance
criteria/Temperature
out of range/Offset
out of limits
Water Saturated air equilibration not
reached
Allow longer equilibration time
Sensor cap loose, scratched, or
damaged
Reposition or replace the LDO sensor cap
Temperature and/or pressure sensor
error Verify that both temperature and pressure sensors are
reading correctly and within range.
1
Damaged probe
Verify both blue and red LEDs are illuminated on the
probe. If not, replace the probe or contact a Hach
Technical Representative.
1 The pressure as measured by the LBOD or LDO is what is referred to as atmospheric pressure and is not corrected to sea
level. Weather station pressures are reported at sea level and commonly referred to as mean sea level pressure. As a result
the LBOD or LDO will not read the same as most household or professional barometers or weather station reports (which are
compensated) unless reported at sea level. In order to compare the pressure results obtained from the LBOD or LDO probe
barometers and these compensated barometers, it is necessary to first compensate the pressure reported by the probes
mathematically.
Troubleshooting (continued)
Message or
symptom Possible cause Action