User manual HANNA INSTRUMENTS HI 2400

[. . . ] HANNA LITERATURE Hanna publishes a wide range of catalogs and handbooks for an equally wide range of applications. The reference literature currently covers areas such as: · · · · · · Water Treatment Process Agriculture Food Laboratory Thermometry Instruction Manual HI 2400 Microprocessor Dissolved Oxygen Bench Meter and many others. For these and others catalogs, handbooks and leaflets, contact your dealer or the Hanna Customer Service Center nearest to you. To find the Hanna Office in your vicinity, check our home page at www. hannainst. com www. hannainst. com MANHI2400 06/03 This instrument is in compliance with the CE directives WWW. HANNAINST. COM Dear Customer, Thank you for choosing a Hanna Instruments product. [. . . ] Make sure that the O-Ring sits properly in the membrane cap. This also indicates the possibility of a broken probe cable. PROBE POLARIZATION The probe is under polarization with a fixed voltage of approximately 800 mV. Probe polarization is essential for stable measurements with the same recurring degree of accuracy. With the probe properly polarized, oxygen is continually "consumed" when it passes through the sensitive diaphragm and dissolves in the electrolyte solution contained in the probe. If polarization is interrupted, the electrolyte solution continues to be enriched with oxygen until it reaches an equilibrium with the surrounding solution. Whenever measurements are taken with a non-polarized probe, the oxygen level revealed is both that of the tested solution as well as that present in the electrolyte solution. Before proceeding with the calibration, make sure the probe is ready for measurements (see page 9), i. e. the membrane cap is filled with electrolyte and the probe is connected to the meter and properly polarized. For an accurate calibration, it is recommended to wait at least 15 minutes to ensure precise conditioning of the probe. Keep the protective cap on during the polarization time and remove it for the calibration and the measurements. Follow the calibration procedure on page 12. 10 31 PROBE & MEMBRANE MAINTENANCE D. O. MEASUREMENTS (in ppm or %) Make sure the meter has been calibrated (see page 12) and the protective cap has been removed. Salinity and Altitude compensation If the sample contains significant concentration of salinity or if you are performing measurements at an altitude different from sea level, the readout values must be corrected, taking into account the lower degree of oxygen solubility in these situations as explained on pages 18-20. Remember to set the altitude and/or the salinity before taking any D. O. Taking measurements Immerse the tip of the probe in the sample to be tested. Allow approximately one minute for the meter to stabilize and read the ppm value of Dissolved Oxygen on the display. The oxygen probe body is made of reinforced plastic for maximum durability. A thermistor temperature sensor provides temperature measurements of the sample. To replace the membrane or refill with electrolyte, proceed as follows: · Remove the protective cap by gently twisting and pulling it off the body of the probe (see fig. · Unscrew the membrane cap by turning it counTWIST terclockwise (see fig. 2). AND · Wet the sensor by soaking the bot tom 2½ PULL cm (1") of the probe in electrolyte (HI 7041S) fig. · Rinse the new membrane cap (HI 76407A) supplied with the meter with electrolyte solution while shaking it gently. · Gently tap the sides of the membrane cap with your finger tip to ensure that no air bubbles remain trapped. [. . . ] The secondary LCD section will show "50. 0°C". Press the CFM key to confirm the baud rate setting. Setting the Command Prefix In the View Settings Mode, press the UP or DOWN arrow keys to display the command prefix; 16 is the factory setting. · Immerse the D. O. · Wait for about 30 seconds until the "CFM" indicator starts blinking. · The temperature calibration procedure is now completed. Press the CAL key to enter the change setting mode, the command prefix will start blinking. [. . . ]