Hanna Instruments HI 222 Instruction Manual

Contents

27All instruments are factory calibrated for mV.Hanna’s pH and ORP electrodes are interchangeable and mV calibration isnot needed when replaced.If mV measurements are not accurate, mV recalibration should be carried out.For an accurate recalibration, contact your dealer or the nearest HannaCustomer Service Center or follow the instructions below.A two or three point calibration can be performed at 0 mV, +600 mV and+1800 mV.• Switch off the instrument.• Attach a mV simulator with an accuracy of at least ±0.1 mV to the BNCconnector.• Press the RCL and CFM/GLP keys simultaneously and switch the instru-ment on. After a few seconds, the instrument enters the mV calibrationmode.• The primary LCD will show the “CAL” and “mV” tags along with mea-sured mV and the secondary LCD will display 0.0 calibration point.• Set 0.0 mV on the simulator.• The “ ” tag will blink on LCD until the reading has stabilized.• When the reading is stable, the “CFM” tag will blink.• Press the CFM key to confirm the calibration.• The instrument will prompt for a second calibration point and will display600 on the secondary LCD line.• Set the simulator to +600.0 mV.• The “ ” tag will blink on the LCD until the reading has stabilized.• When the reading is stable, the “CFM” tag will start to blink.• Press the CFM key to confirm the calibration.• The instrument will prompt for a third calibration point and will display1800 on the secondary LCD line.• The two-point mV calibration is now complete.• Set +1800.0 mV on the simulator.• The “ ” tag will blink on the LCD until the reading has stabilized.• When the reading is stable, the “CFM” tag will start to blink.• Press the CFM key to confirm the calibration.• The instrument will memorize the calibration and return to measuringmode.mV CALIBRATION(for technical personnel only)