User Instructions

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CALIBRATION
Press CAL from any measure mode (DO, BOD, OUR or SOUR). The calibration menu will be displayed.
Press Pressure functional key to select the pressure calibration. The pressure calibration screen will
be displayed.
Using the / keys, enter the true local barometric pressure reading from the reference barometer.
DO NOT use the pressure reported by the weather bureau. Weather bureaus correct pressures to sea
level.
When the reading is stable within range of the entered barometric pressure the CFM functional key
is displayed.
Press CFM to confirm the calibration.
The meter will return to the measurement screen and will store the calibration data.
”CAL DUE” will be displayed and a probe calibration must follow.
To clear the pressure calibration and restore the factory one, press CAL from any measure mode (DO,
BOD, OUR or SOUR).
The calibration menu will be displayed. Press the Pressure functional key and then Clear.
The user calibration will be removed and the factory calibration restored.
Press ESC key at any time to exit the calibration without changing values.
9.3. TEMPERATURE CALIBRATION
The HI764113 has been factory calibrated for temperature. Dissolved oxygen values are based upon
temperature compensation so accurate temperature measurements are required. Should a thermistor
go out of tolerance, your measurement will be compromised. An additional user temperature
calibration of the HI764113 optical dissolved oxygen probe may be performed if desired.