Hanna Instruments HI 993310 User Manual

Page 8

OPERATIONAL GUIDE

• Each meter is supplied complete with a 9V battery. Slide off the

battery compartment cover on the back of the meter and install
the battery while paying attention to its polarity.

• Connect the proper probe to the meter: use HI 76305 for

measuring soil activity or HI 76304 for conductivity.

• Securely connect the probe to the meter

by aligning the pins with the socket and
pushing the plug in. Always detach the
probe by holding it by the connector
(and not by the cable).

• Make sure the meter has been calibrated before taking any

measurements.

• Immerse the conductivity probe into the

sample to be measured (approximately
5 cm/2"). If possible, use plastic beakers
or containers to minimize EMC interfer-
ences.

• For soil activity measurements, directly insert the stainless steel

probe in the soil to a depth of 15 cm (6").

• Turn the instrument on by pressing the

ON/OFF key.

• Press "W" if using conductivity probe for,

or "S" if using soil probe.

Note: Change the probe for taking different type of measurement.

• For Water Conductivity range, wait a couple of minutes for

reaching thermal equilibrium before taking any measurements.
If the sample's temperature is lower than 20°C or higher than
30°C, allow more time for the thermal equilibrium to be achieved.

• The meter provides for a LED alarm when measuring soil activity.

If the LED lights up, the soil is too dry for a proper measurement
or it lacks nutritive substances.
Wet the soil with a moderate quantity of demineralized water
and carry out the measurement again. If the alarm LED lights
up, the soil lacks nutritive elements.

CALIBRATION

The soil activity range is calibrated by performing the calibration of
the conductivity range.
Should the soil activity measurements be not calibrated, contact the
nearest Hanna service center for re-calibration.

CALIBRATION PROCEDURE

• Pour sufficient quantity of a conductivity

calibration solution (e.g. HI 7030) into
a beaker. If possible, use plastic beaker
to minimize any EMC interference.

• Immerse the conductivity probe in the

solution (approximately 5 cm/2").

• Press the ON/OFF button to turn the meter on, and then press

the "W" button to enter the Water Conductivity mode.

• Wait a couple of minutes for thermal equilibrium to be reached.
• Turn the calibration knob until the display shows the conductivity

value of the calibration solutions at 25°C (e.g. 12.88 mS/cm).

• All subsequent measurements will be compensated to 25°C (77°F).

The calibration is now complete and the meter is ready for use.

Notes:
• It is recommended to calibrate the meter at least once a month,

and every time the probe or the battery is changed.

• For more accurate measurements, use a calibration solution close to

the range to be measured. See the "Accessories" section for a
selection of conductivity calibration solutions.