User manual HANNA INSTRUMENTS HI 9142

[. . . ] Four 1. 5V AA batteries provide power and make the instrument completely portable. The meter is housed in a rugged water-resistant case for maximum protection in the field as well as in the laboratory. ISO 9000 Certified Company since 1992 The dissolved oxygen probe has a membrane covering the polarographic sensors and a built1 in thermistor for temperature measurements and compensation. The thin permeable membrane isolates the sensor elements from the testing solution, but allows oxygen to enter. When a voltage is applied across the sensor, oxygen that has passed through the membrane reacts causing current to flow, allowing the determination of oxygen. [. . . ] · Switch the meter on by pressing the ON/OFF key Zero Calibration: · Dip the probe into HI 7040 zero oxygen solution and stir gently for 2-3 minutes. Note The zero calibration screw is located close to the probe connector. Slope Calibration: It is suggested to perform the slope calibration in satured air. · Rinse the probe in a large amount of clean water to remove any residual zero oxygen solution. · Dry the probe tip and allow a few minutes for the LCD readout to stabilize. · Adjust the slope trimmer on the top of the meter to read "100%" on the LCD (while still holding the CAL button). Note The slope calibration screw is located farthest from the probe connection. · Release the CAL key and the LCD will display the value in ppm of oxygen. CAL ON/OFF · For an accurate calibration, it is recommended that you wait at least 15 minutes to ensure precise conditioning of the probe. probe. % The zero calibration of the HI 9142 is very stable, therefore this procedure needs only to be performed whenever the probe is replaced. However, because the slope calibration is more critical, it is recommended to perform this procedure every week. 6 7 TAKING MEASUREMENTS Make sure the meter has been calibrated and the protective cap has been removed. For accurate dissolved oxygen measurements a water movement of 0. 3 m/sec is required at a minimum. This is to ensure that the oxygendepleted membrane surface is constantly replenished. To quickly check if the water speed is sufficient, wait for the reading to stabilize and then move the D. O. If the reading is still stable, the measurement conditions are right, while if the reading increases the water movement is not adequate. During field measurements, this condition may be met by manually agitating the probe. During laboratory measurements, the use of a magnetic stirrer to ensure a certain velocity in the fluid is recommended. In this way, errors due to the diffusion of the oxygen present in the air in the solution are reduced to a minimum. At all times, time necessary for thermal equilibrium to occur between the probe and the sample must be allowed (a few minutes for temperature difference of several degrees). ALTITUDE & SALINITY COMPENSATION If the sample contains salts or if you are performing the measurements at a different altitude than sea level, the readout values must be corrected, taking into account the lower degree of oxygen solubility. ALTITUDE COMPENSATION All the readouts are referred at sea level, thus the displayed measurements are higher than the actual values. The following table reports the oxygen solubility at various temperatures and altitudes, based on sea level barometric pressure of 760 mm Hg. Altitude, Meters above Sea Level °C 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 0m 300 m 600 m 900 m 1200 m 1500m 1800m °F 32. 0 35. 6 39. 2 42. 8 46. 4 50. 0 53. 6 57. 2 60. 8 64. 4 68. 0 71. 6 75. 2 78. 8 82. 4 86. 0 89. 6 93. 2 96. 8 100. 4 104. 4 14. 6 13. 8 13. 1 12. 4 11. 8 11. 3 10. 8 10. 3 9. 9 9. 5 9. 1 8. 7 8. 4 8. 1 7. 8 7. 5 7. 3 7. 1 6. 8 6. 6 6. 4 14. 1 13. 3 12. 7 12. 0 11. 4 10. 9 10. 4 9. 9 9. 7 9. 2 8. 8 8. 4 8. 1 7. 8 7. 5 7. 2 7. 1 6. 9 6. 6 6. 4 6. 2 13. 6 12. 9 12. 2 11. 6 11. 0 10. 5 10. 1 9. 6 9. 2 8. 7 8. 5 8. 1 7. 8 7. 5 7. 3 7. 0 6. 8 6. 6 6. 3 6. 2 6. 0 13. 2 12. 4 11. 9 11. 2 10. 6 10. 2 9. 7 9. 3 8. 9 8. 6 8. 2 7. 8 7. 5 7. 3 7. 0 6. 8 6. 6 6. 4 6. 1 5. 9 5. 8 12. 7 12. 0 11. 4 10. 8 10. 3 9. 8 9. 4 9. 0 8. 6 8. 3 7. 9 7. 7 7. 3 7. 0 6. 8 6. 5 6. 4 6. 2 5. 9 5. 7 5. 6 12. 3 11. 6 11. 0 10. 4 9. 9 9. 5 9. 1 8. 7 8. 3 8. 0 7. 7 7. 3 7. 1 6. 8 6. 6 6. 3 6. 1 6. 0 5. 7 5. 6 5. 4 11. 8 11. 2 10. 6 10. 1 9. 6 9. 2 8. 8 8. 3 8. 0 7. 7 7. 4 7. 1 6. 8 6. 6 6. 3 6. 1 5. 9 5. 8 5. 5 5. 4 5. 2 This gives an idea of the error that can be introduced at different altitudes and allows you to calculate the quantity to be subtracted to correct your reading. 8 9 SALINITY COMPENSATION The table below shows the influence of salt in the measurement of oxygen. In HI 9142 all the readouts are referred to 0 g/l of salinity value. For your reference the table below reports the oxygen solubility at various temperatures and salinity. From the table you can calculate the quantity to be subtracted to correct your reading. PROBE & MEMBRANE MAINTENANCE The oxygen probe body is made of reinforced plastic for maximum durability. A thermistor temperature sensor provides temperature measurements of the sample tested. [. . . ] When shipping any instrument, make sure it is properly packaged for complete protection. To validate your warranty, fill out and return the enclosed warranty card within 14 days from the date of purchase. All rights are reserved. Reproduction in whole or in part is prohibited without the written consent of the copyright owner. Hanna Instruments reserves the right to modify the design, construction and appearance of its products without advance notice. 14 15 OTHER PRODUCTS FROM HANNA · CALIBRATION AND MAINTENANCE SOLUTIONS · CHEMICAL TEST KITS · CHLORINE METERS · CONDUCTIVITY/TDS METERS · DISSOLVED OXYGEN METERS · HYGROMETERS · ION SPECIFIC METERS (Colorimeters) · MAGNETIC STIRRERS · pH/Na/NaCl METERS · pH/ORP/Na ELECTRODES · PROBES (DO, µS/cm, RH, T, TDS) · PUMPS · REAGENTS · SOFTWARE · THERMOMETERS · TITRATORS · TRANSMITTERS · TURBIDITY METERS · Wide Range of Accessories Most Hanna meters are available in the following formats: · BENCH-TOP METERS · POCKET-SIZED METERS · PORTABLE METERS · PRINTING/LOGGING METERS · PROCESS METERS (Panel and Wallmounted) · WATERPROOF METERS · METERS FOR FOOD INDUSTRY For additional information, contact your dealer or the nearest Hanna Customer Service Center. You can also e-mail us at: tech@hannainst. com. CE DECLARATION OF CONFORMITY Recommendations for Users Before using this product, make sure that it is entirely suitable for the environment in which it is used. [. . . ]