User manual HANNA INSTRUMENTS HI 96785C

[. . . ] 5 SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 PRINCIPLE OF OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 FUNCTIONAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 ERRORS AND WARNINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] The cuvette 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) cuvettes, are optically identical to provide the same measurement conditions. Whenever possible use the same cuvette for both. It is necessary that the surface of the cuvette is clean and not scratched. This to avoid measurement interference due to unwanted reflection and absorption of light. It is recommended not to touch the cuvette walls with hands. Furthermore, in order to maintain the same conditions during the zeroing and the measuring phases, it is necessary to close the cuvette to prevent any contamination. PRINCIPLE OF OPERATION Absorption of Light is a typical phenomenon of interaction between electromagnetic radiation and matter. When a light beam crosses a substance, some of the radiation may be absorbed by atoms, molecules or crystal lattices. If pure absorption occurs, the fraction of light absorbed depends both on the optical path length through the matter and on the physical-chemical characteristics of the substance according to the Lambert-Beer Law: -log I/Io = c d or A = c d Where: -log I/Io Io I c d = = = = = = Absorbance (A) intensity of incident light beam intensity of light beam after absorption molar extinction coefficient at wavelength molar concentration of the substance optical path through the substance 6 7 FUNCTIONAL DESCRIPTION INSTRUMENT DESCRIPTION 1) 2) 3) 4) 5) CAL key READ key ON/OFF key Liquid Crystal Display (LCD) Cuvette holder ERRORS AND WARNINGS The instrument shows clear messages when erroneous condition appears. Messages are also displayed when the obtained values are outside expected range. a) on calibration Light High: There is too much light to perform a measurement. Please check the preparation of the calibration cuvette. KEYPAD DESCRIPTION · ON/OFF: to turn the meter on and off. · CAL: to calibrate the meter prior to measurement. OPERATING MODES · Measurement mode: default operation mode, enables both calibration and measurement. DISPLAY ELEMENTS DESCRIPTION b) on sample reading Light Low: There is not enough light to perform a measurement. Please check the preparation of the calibration cuvette. No Light: The instrument cannot adjust the light level. Please check that the calibration cuvette does not contain any debris. Inverted Cuvettes: The sample and the calibration cuvette are inverted. 1) The measuring scheme (lamp, cuvette, detector), appears during different phases of zero or reading measurement 2) Error messages and warnings 3) The battery icon shows the charging level of the battery 4) The hourglass appears when an internal checking is in progress 5) Status message 6) Four digit main display 8 CAL: A Calibration reading was not taken. Follow the instructions of the measurement procedure for calibrating the meter. 9 Under range: A blinking "0" indicates that the sample absorbs less light than the calibration reference. Check the procedure and recalibrate the instrument. Over Range: A flashing value of the maximum concentration indicates an over range condition. The concentration of the sample is beyond the programmed range. GENERAL TIPS FOR AN ACCURATE MEASUREMENT The instructions listed below should be carefully followed during testing to ensure best accuracy. · Use matched square cuvettes, having 4 clear faces and 10 mm path length. [. . . ] · Turn the instrument upside down and remove the battery cover by turning it counterclockwise. · Extract the battery from its location and replace it with a fresh one. · Insert back the battery cover and turn it clockwise to close. 14 Recommendations for Users Before using these products, make sure that they are entirely suitable for your specific application and for the environment in which they are used. Operation of these instruments may cause unacceptable interferences to other electronic equipments, this requiring the operator to take all necessary steps to correct interferences. [. . . ]