Manual

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 probe preparation

on page 8), i.e. the membrane 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 conditioning of the probe.

• Remove the protective cap from the DO probe.

• Set the appropriate altitude factor (see

page 19). Make sure the salinity factor is

set to zero (see page 18).

ZERO CALIBRATION

• Submerge the probe into HI 7040

zero oxygen solution and stir gently

for 2-3 minutes.

• Press CAL. The “ ” and “NOT READY”

tags will blink on the LCD until the

reading is stable.

• When the reading is stable,and is within

the limits (±15% f.s.) “CFM” starts

blinking. Press CFM to confirm the

“0.0%” DO calibration.

• Press CAL. The instrument will return to measurement mode and will

memorize the zero calibration data. For a

two-point calibration do not press CAL and

follow the procedure below.