Ec/Tds Calibration; Ec/Tds Conversion Factor; Battery Replacement - Hanna Instruments HI 9811-5 Instruction Manual

EC/TDS CALIBRATION

Accessories needed:
• Use HI 70031 (1413 µS/cm) EC calibration solution or HI
70032 (1382 ppm, or mg/L) TDS calibration solution.
Note: The conversion between EC and TDS is made by a built-in
circuit, hence it is requested to calibrate the meter only in EC
or TDS range. The other range is thus automatically cali-
brated.
PROCEDURE
• Pour approximately 4 cm (1½") of a conductivity calibration
solution (e.g. HI 70031) into a beaker. If possible, use plastic
beaker to minimize any EMC interference.
• Immerse the probe in the solution.
• Wait for a couple of minutes for thermal equilibrium to be
reached.
• Tap the probe on the bottom, then shake it lightly while rotating
to make sure no air bubbles remain trapped inside the probe.
• Press the "µS/cm" (or "mg/L") key.
• Turn the EC/TDS calibration knob until
the display shows the EC or TDS reading
at 25°C.

EC/TDS CONVERSION FACTOR

The TDS value in aqueous solutions is directly proportional to the
conductivity. The ratio between the two parameters depends on the
solution.
Both HI 9811-0 and HI 9811-5 models have a fixed conversion
factor set to 0.5. This means that 1 µS/cm is equal to 0.5 mg/L
of TDS.
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BATTERY REPLACEMENT

These meters are powered by a 9V battery that is located on the rear
of the instrument.
When the battery level is so low that it may cause unreliable
measurements, the meter turns off.
It is recommended to replace the battery immediately.
Battery replacement must only take place in a nonhazardous area
using a 9V alkaline battery.
Unscrew the three screws on the rear of the meter, remove the battery
compartment cover and replace the 9V battery with a new one while
paying attention to its polarity.
Make sure the battery contacts are tight and secure before replacing
the cover.
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