User Guide

The meter is equipped with a stability indicator and the user will be guided

step by step with symbols on the display during the D.O. calibration. This will

make the calibration a simple and error-free procedure.

The zero calibration of the HI 2400 is very stable, therefore this procedure

needs only to be performed whenever the probe or the membrane is

replaced.

However, because the slope calibration is more critical, it is recommended

to perform this procedure every week.

INITIAL PREPARATION

• Pour small quantities of HI 7040 Zero Oxygen

solution into a beaker. If possible, use a plastic

beaker to minimize any EMC interferences.

• Make sure the probe is ready for measurements

(see initial preparation at page 9), i.e. the mem-

brane is filled with electrolyte and the probe is

connected to the meter.

• Switch the meter on by pressing the ON/OFF switch.

• For an accurate calibration, it is recommended to

wait for at least 15 minutes to ensure precise condi-

tioning of the probe.

• Remove the protective cap from the D.O. probe.

• Set the appropriate altitude factor (see page 19).

Make sure the salinity factor is set to zero (see page

18).

ZERO CALIBRATION

• Dip the probe into HI 7040 zero oxygen solution

and stir gently for 2-3 minutes.

HI 7040

Note : If the ON/OFF switch is pressed while

logging, the meter will stop the logging

first and then will turn off.

MEMORY ORGANIZATION

The memory used for storing the logged data is divided into 16 pages. The

capacity of each page is 500 samples. It starts to log from page 16 downwards

until 1 and then 16 again, overwriting the previous data. However, when

this happens the LCD will show page “0”, indicating overwriting has occurred.

Each time a new logging period starts, it automatically starts from a new

page.

When the samples collected for a single lot are more than the limit (8000

samples) the meter will stop logging automatically.

TO CLEAR LOGGED DATA

The entire logged data can be cleared by pressing the ON/OFF switch and the

LOG key simultaneously.

The choice has to be confirmed by pressing the CFM key.