User manual HANNA INSTRUMENTS HI 96730

[. . . ] Follow the instructions of the measurement procedure for zeroing the meter. Under range: A blinking "0. 00" indicates that the sample absorbs less light than the zero reference. Check the procedure and make sure you use the same cuvette for reference (zero) and measurement. Over Range: A flashing value of the maximum concentration indicates an over range condition. [. . . ] 6· After a few seconds the display will show "-0. 0-". The meter is now zeroed and ready for measurement. 7· Fill one graduated mixing cylinder up to the 25 mL mark with sample. 8· Add the content of one packet of HI 93730A-0 Molybdenum reagent, close the cylinder and invert it several times until the powder is completly dissolved. 9· Add the content of one packet of HI 93730B-0 Reagent B to the cylinder, close it and invert several times until the powder is completely dissolved. 10·Add the content of one packet of HI 93730C-0 Reagent C to the cylinder, close and shake it vigorously. 11·Fill a cuvette with 10 mL of the reacted sample up to the 10 mL mark and replace the cap. 12·Place the cuvette into the cuvette holder and ensure that the notch on the cap is positioned securely into the groove. 13·Press and hold READ/ /TIMER for three seconds and the display will show the 13 countdown prior to measurement or alternatively wait for 5 minutes and press READ/ /TIMER. An audible "beep" indicates the end of countdown period. In all cases the lamp, cuvette and detector icons will appear on the display, depending or on the measurement phase. 14·At the end of measurement, the instrument directly displays concentration in mg/L of molybdenum on the LCD. INTERFERENCES: Interference may be caused by: Aluminum above 50 mg/L 14 Chromium above 1000 mg/L Copper above 10 mg/L Iron above 50 mg/L Nickel above 50 mg/L Nitrite, as NO2 Sulfate above 200 mg/L Highly buffered samples or with extreme pH may exceed the buffering capacity of the reagents. ­ 9· At the end of the measurement the display will show the validation standard value. The reading should be within specifications as reported on the CAL CHECKTM Standard Certificate. If the value is found out of specifications, please check that the cuvettes are free of fingerprints, oil or dirt and repeat validation. If results are still found out of specifications then recalibrate the instrument. 9 11·Then the date of last calibration (e. g. : "01. 08. 2009") appears on the display, or "01. 01. 2009" if the factory calibration was selected before. In both cases the year number is blinking, ready for date input. 12·Press GLP/ to edit the desired year (2009-2099). If the key is kept pressed, the year number is automatically increased. 13·When the correct year has been set, press ZERO/CFM or READ/ /TIMER to confirm. Now the display will show the month blinking. Calibration 14·Press GLP/ to edit the desired month (01-12). If the key is kept pressed, the month number is automatically increased. [. . . ] For accurate validation and calibration results, please perform tests at room temperature (18 to 25°C; 64. 5 to 77. 0°F). Use the Hanna CAL CHECKTM cuvettes (see "Accessories") to validate or calibrate instruments. Validation 16·Press GLP/ to edit the desired day (01-31). If the key is kept pressed, the day number is automatically increased. [. . . ]