User manual HANNA INSTRUMENTS HI 9146

[. . . ] The ppm and the % saturation are both compensated for changes in solubility of oxygen in water and for permeability of the membrane as well as the temperature effect. 3 Salinity compensation in water allows determination of mg/L of dissolved oxygen in salty waters and the altitude compensation readjusts for the altitude variance. Four 1. 5V AA alkaline batteries provide power and make the instrument completely portable. HI 9146 is also designed to be used with a battery recharger or a 12 Vdc power supply. [. . . ] Whenever measurements are taken with a non-polarized probe, the oxygen level indicated is that of the test solution as well as any oxygen present in the electrolyte solution. The Hanna oxygen meter shown here automatically polarize the probe when they are switched on. Calibration is simple and is recommended every time the meter is switched on. · Make sure the probe is ready for measurement (see page 5), i. e. the membrane is filled with electrolyte and probe is connected to the meter and properly polarized. · "COND" appears on the display to inform you that ON/OFF the probe is in auto-conditioning (automatic polarization) mode. · Once "COND" disappears the probe is polarized and instrument can be calibrated. · For an accurate calibration, it is recommended to wait an additional 5 or 10 minutes to ensure optimum conditioning of the probe. "----" appears on the larger LCD together with "CAL" to indicate that the instrument is in calibration mode. The instrument will automatically standardize itself to the actual saturation value. 1 minute it will show "100%" on the LCD and a small "SAMPLE" to indicate that the calibration is complete. CAL CAL SAMPLE % °C · Press FACTOR and ensure F1 and F2 are set to the appropriate altitude and salinity values (pages 10-11). Notes: · The instrument must be calibrated whenever the probe, membrane or the electrolyte is changed. · The display may be switched from readings in % saturation to mg/ CAL L without recalibration, by simply pressing RANGE. RANGE 8 9 MEASUREMENT Make sure the meter has been calibrated and the protective cap has been removed. Immerse the tip of the probe in the sample to be tested and ensure that the temperature sensor is also immersed. To display values in % saturation, press RANGE. RANGE If the sample contains significant salinity or if the measurement is taken at a higher altitude than sea level, the read-out values must be corrected (by taking into account the lower degree of oxygen solubility in such conditions - see below). Set the altitude and/or the salinity before calibration and taking mg/L measurements. The meter will automatically compensate for these factors. For accurate dissolved oxygen measurements, a water movement of at least 30 cm (12")/sec is required. This is to ensure that oxygen depleted on the membrane surface is constantly replenished. During field measurements, this condition may be obtained by manually stirring the probe. During laboratory measurements, the use of a magnetic stirrer to ensure a certain agitation of the fluid is recommended. This way, any errors due to the presence of air bubbles on the membrane surface are minimized. For an accurate measurement, allow sufficient time for thermal equilibrium between the probe and the measurement sample (a few minutes if the temperature difference is several degrees). % O2 SATURATION READINGS The % O2 reading provides the rate of oxygen saturation with reference to 100. 0% at sea level. TEMPERATURE READINGS The lower part of the display will show the measured temperature in Celsius degrees. SAMPLE % °C Allow the probe to reach thermal equilibrium with the sample before taking any measurement. The greater the difference between the ambient temperature and the temperature of the sample, the longer it will take the probe to acclimatized itself to the sample. mg/L READINGS The mg/L readings make it possible to read the concentration of the dissolved oxygen directly in ppm. 10 11 ALTITUDE COMPENSATION SALINITY COMPENSATION Press FACTOR and "F1" will be displayed. SAMPLE FACTOR ppm F1 Use the UP and the DOWN keys to set the altitude from 0 and 4. 0 km (4000 m), in steps of 0. 1 km (100 m). or Press FACTOR twice and "F2" will be displayed. Install a new membrane and fill it with fresh electrolyte following the instructions above. [. . . ] If the repair is not covered by the warranty, you will be notified of the charge for repair or replacement. If the instrument is to be returned to Hanna Instruments, please obtain a Return Goods Authorization from the Customer Service Department and then send it with shipment cost prepaid. When shipping any instrument, make sure it is properly packaged for complete protection. Recommendations for Users Before using these products, make sure that they are entirely suitable for the environment in which they are used. Operation of this instrument in residential area could cause unacceptable interference to radio and TV equipment, requiring the operator to take all necessary steps to correct interferences. [. . . ]