User manual HANNA INSTRUMENTS HI 83742

[. . . ] Instruction Manual HI 83742 COLOR & PHENOLS ISM for wine analysis MAN83742R3 04/06 w w w . h a n n a i n s t . c o m www. hannainst. com This Instrument is in Compliance with the CE Directives Dear Customer, Thank you for choosing a Hanna product. This manual will provide you with the necessary information for the correct use of the instrument. Please read it carefully before using the meter. If you need additional technical information, do not hesitate to e-mail us at tech@hannainst. com. [. . . ] Accuracy is defined as the nearness of a test result to the true value. Although good precision suggests good accuracy, precise results can be inaccurate. Given that the absorption of a compound strictly depends on the wavelength of the incident light beam, a narrow spectral bandwidth should be selected as well as a proper central wavelength to optimize measurements. The optical system of Hanna's HI 83000 series colorimeters is based on special subminiature tungsten lamps and narrow-band interference filters to guarantee both high performance and reliable results. · Replace the cap and shake gently to mix. This is the diluted red wine sample. Block diagram (optical layout) · Take another empty cuvet and use the 5 mL syringe to add exactly 5 mL of HI 83742A-0 reagent to an empty cuvet. Note: in order to measure exactly 5 mL of reagent with the syringe, follow the instructions on page 11. 23 6 MEASUREMENT · Press "RANGE" to select the parameter code "P4" for total phenols, white wine (see page 13). · Fill an empty cuvet with deionized water and replace the cap. · Insert the zero cuvet into the holder and close the lid. #1 (Zero) · Press ZERO and "----" will blink on the display. · After a few seconds the display will show "-0. 0-". The meter is now zeroed and ready for measurement. · Remove the cuvet from the instrument. · Insert the sample (cuvet #2) into the holder and close the lid. A microprocessor controlled special tungsten lamp emits radiation which is first optically conditioned and beamed to the sample contained in the cuvet. The optical path is fixed by the diameter of the cuvet. Then the light is spectrally filtered to a narrow spectral bandwidth, to obtain a light beam of intensity Io or I. The photoelectric cell collects the radiation I that is not absorbed by the sample and converts it into an electric current, producing a potential in the mV range. The microprocessor uses this potential to convert the incoming value into the desired measuring unit and to display it on the LCD. The measurement process is carried out in two phases: first the meter is zeroed and then the actual measurement is performed. The cuvet has a very important role because it is an optical element and thus requires particular attention. It is important that both the measurement and the calibration (zeroing) cuvets are optically identical to provide the same measurement conditions. Whenever possible use the same cuvet for both. It is necessary that the surface of the cuvet is clean and not scratched. This to avoid measurement interference due to unwanted reflection and absorption of light. [. . . ] · The instrument directly displays the color density on the Liquid Crystal Display. #2 (Sample) INTERFERENCES Suspended matter should be removed by centrifugation or prior filtration. Use an adequate filter material that does not absorb color. 12 17 COLOR DENSITY, RED WINE SPECIFICATIONS Range Resolution Precision Light Source Method 0. 00 to 15. 00 0. 01 ±0. 20 @ 5. 00 Tungsten lamp with narrow band interference filters @ 420 and 520 nm Direct reading. Quantity/test 8 mL 8 mL [optional reagent] OPERATIONAL GUIDE MEASUREMENT PROCEDURE · Turn the instrument on by pressing ON/OFF. [. . . ]