Hanna Instruments pH 211R Instruction Manual

Contents

Hanna Instruments pH 211R Instruction Manual Manual pdf 4 page image

76If measurements are taken successively in different samples, it isrecommended to rinse the electrode thoroughly with water and thenwith some of the next sample to be measured.pH readings are affected by temperature. In order for the meter tomeasure the pH accurately, temperature must be taken into consid-eration. To use the Automatic Temperature Compensation (ATC)feature, submerge the HI 7669/2W temperature probe into thesample as close to the electrode as possible and wait for a couple ofminutes.If the temperature of the sample is known or tests are alwaysperformed at the same temperature, you can simply manuallycompensate for it. For this purpose the temperature probe must bedisconnected.The display will then show the default tem-perature of 25°C with the "°C" symbol blinking.Note the temperature of the sample using aChecktempC (HI 98501) or another accuratethermometer as reference.The temperature can now be adjusted with the s°C and t°C keys.TAKING ORP MEASUREMENTSAn optional ORP electrode must be used to perform ORP measure-ments (see accessories).Oxidation-reduction potential (REDOX) measurements provide thequantification of the oxidizing or reducing power of the sample tested.To correctly perform a redox measurement, the surface of the ORPelectrode must be clean and smooth.OPERATIONAL GUIDEPower ConnectionPlug the 12 Vdc adapter into the power supply socket.Note: Make sure the mains line is protected by a fuse.Electrode and Probe ConnectionsConnect the BNC of the pH or ORP electrode to the BNC socket on therear panel.For electrodes with a separate reference, connect the reference elec-trode plug to the reference socket (#12 on page 4).For temperature measurements and automatic temperature compen-sation, connect the temperature probe to the appropriate socket.Note: To prevent damage to the pH electrode, remove it from thesolution before turning the meter off.With the meter OFF, detach the electrode from the meter andimmerse it in the storage solution.TAKING pH MEASUREMENTSMake sure that the instrument has been calibrated for pH beforetaking pH measurements.• Switch the instrument on by pressing theON button. The meter automatically de-faults to the pH measurement mode.• Submerge the tip (4 cm / 1½") of theelectrode and temperature probe into thesample to be tested. Allow a couple ofminutes for the electrode to stabilize.• The pH reading is displayed on the primary LCD and temperatureon the secondary one.• To view the mV reading, press the RANGE key.4 cm(1½")