Hanna Instruments HI 9811 - Manual (Page 11)

11
The TDS value in aqueous solutions is directly proportional to the
conductivity. The ratio between the two parameters depends on the
solution.
HI 9811-5 model has a fixed conversion factor set to 0.5. This
means that 1
µ
S/cm is equal to 0.5 mg/L of TDS.
Accessories needed:
• Use HI 70031 (1413 µ S/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
calibrated.
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
µ
S/cm (or mg/L) key.
• Turn the EC/TDS calibration knob until
the display shows the EC or TDS reading
at 25°C.
E C / T D S E C / T D S E C / T D S E C / T D S E C / T D S C A L I B R A T I O N C A L I B R A T I O N C A L I B R A T I O N C A L I B R A T I O N C A L I B R A T I O N
E C / T D S C O N V E R S I O N F A C T O R E C / T D S C O N V E R S I O N F A C T O R E C / T D S C O N V E R S I O N F A C T O R E C / T D S C O N V E R S I O N F A C T O R E C / T D S C O N V E R S I O N F A C T O R