Chapter 7 - Calibration Mode - Hanna Instruments HI 9829 Instruction Manual

Chapter 7 - CALIBRATION MODE

HI 9829's calibration routines are accessed by highlighting "Calibration" and
pressing <Select> from the main menu. Calibration is the process that stan-
dardizes the electrical or optical signals from the sensors to reagent standards
of known value.
Calibrations are intuitive and menu driven. All
calibration data is stored in the non volatile probe
memory, allowing probes to be connected to
different meters without recalibration.
There are two types of calibrations available: the
"Quick calibration", which is used for a single
point calibration of pH, Conductivity, and/or
Dissolved Oxygen and is handy for field work;
and the "Single param. calibration" that allows each parameter to be
calibrated individually. The user may also restore each parameter to a factory
default calibration.
Note The password will be required if password protection is enabled.
To optimize measurements, it is advisable to establish the optimum calibration
period required for the measurement environment.
Calibration requirements vary with deployment conditions, for example very turbid
biologically-active waters may require more frequent cleanings and calibrations
than cleaner waters.
General calibration guidelines are listed below:
• Set up a routine service schedule where measurement integrity is validated.
This is especially important for new installation sites or long deployments.
• Inspect sensor connectors for corrosion and replace damaged sensors.
• Inspect sensor o-rings for damage and if necessary replace and lubricate
with the grease found in the probe maintenance kit.
• Do not handle the sensing surfaces of the sensors.
• Avoid rough handling and abrasive environments that can scratch the
reactive surfaces of the sensors.
• Avoid long-term exposure of sensors to bright sunlight (especially chloride
ISE). If possible, calibrate in a shaded area.
• Discard standards after use. Do not return the used standards to the bottles
of "fresh" solution.
• For measurements across a temperature gradient (when water temperature
is drastically different from the standards), permit the sensors to reach thermal
equilibrium before conducting calibrations or making measurements. The
heat capacity of the probe is much greater than the air and the small beakers
of calibration standards.
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