Manual

Each meter has been factory calibrated for temperature with the supplied

DO probe and is ready for measurements.

The DO probes are interchangeable and no temperature calibration is

needed.

If the temperature measurements are not accurate, temperature

recalibration should be performed.

For an accurate recalibration, contact your dealer or the nearest Hanna

Customer Service Center, or follow the procedure below.

• Prepare a vessel containing ice and water and another one containing

hot water (at a temperature of around 50 °C). Place insulation

material around the vessels to minimize temperature changes.

• Use a calibrated thermometer with a resolution of 0.1 °C as a

reference thermometer. Connect the HI 76407/2 DO probe to the

appropriate socket.

• With the instrument off, press and hold down CFM&SETUP, then

power on the instrument. The “CAL” tag will appear and the

secondary LCD will show “0.0 °C”.

• Submerse the DO probe in the vessel with ice

and water as near as possible to the reference

thermometer. Allow a few seconds for the probe

to stabilize.

• Use the ARROW keys to set the reading on

the secondary LCD to that of ice and water,

measured by reference thermometer. When

the reading is stable, the “CFM” tag starts blinking.

• Press CFM to confirm. The secondary LCD will show “50.0 °C”.

TEMPERATURE CALIBRATIONTEMPERATURE CALIBRATION

TEMPERATURE CALIBRATION

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for technical personnel onlyfor technical personnel only

for technical personnel only

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