Chapter 7 - Calibration Mode; Quick Calibration - Hanna Instruments HI 98194 Instruction Manual

Chapter 7 - CALIBRATION MODE

HI 9819X's calibration routines are accessed by highlighting "Calibration"
and pressing Select from the main menu. Calibration is the process that
standardizes the electrical signal 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. 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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7.1 QUICK CALIBRATION

The quick calibration method provides a quick single point calibration for pH,
conductivity and dissolved oxygen sensors. HI 9828-25 calibration solution is
used for both pH and conductivity.
• Fill the calibration beaker 2/3 full with HI 9828-25 calibration solution.
• Slowly place the sensors into the solution and
dislodge bubbles that may adhere to the sensors.
• Screw the calibration beaker completely on the
probe body. Some solution may overflow.
• Wait a few minutes for the system to stabilize.
• From the "Calibration" menu select "Quick
calibration".
• A three item calibration menu will appear (pH,
Conductivity and Dissolved oxygen) and "pH"
will start to blink along with the "Not ready"
message.
• When the pH signal is stable, the "Ready"
message appears. Press Confirm to store the
calibration data.
• The "Storing" message will appear as the
calibration proceeds to the next sensor. A
checkmark will appear in the box next to "pH"
to indicate a successful calibration.
Note To bypass any of the calibrations press
Skip to move to the next sensor in the
quick calibration menu.
If the pH sensor is not installed the
message "pH sensor not installed! Skip
to conductivity calibration" will appear.
• Following the pH calibration, "Conductivity" will start to blink along with the
"Not ready" message.
• When the measurement is stable, "Ready" appears. Press Confirm to store
the calibration data and the "Storing" message will appear.
Note If EC calibration is not required, skip to
the D.O. quick calibration by pressing the
Skip softkey.
• The message "Empty the beaker." will appear.
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