User manual HANNA INSTRUMENTS HI 96719C

[. . . ] Instruction Manual HI 96719C Magnesium Hardness ISM www. hannainst. com 1 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. TABLE OF CONTENTS PRELIMINARY EXAMINATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] · It is possible to take multiple readings in a row, but it is recommended to take a new zero reading for each sample and to use the same cuvette for zeroing and measurement. · After the reading it is important to discard immediately the sample, otherwise the glass might become permanently stained. · All the reaction times reported in this manual are referred to 20°C (68°F). As a general rule of thumb, they should be doubled at 10°C (50°F) and halved at 30°C (86°F). · In order to maximize accuracy, prior to a measurement follow the validation procedure to be sure that the instrument is properly calibrated. If necessary, calibrate the instrument. STARTUP Prepare the instrument for measurement as follows: · Unpack the instrument by removing the dust protection sleeve from the instrument cuvette holder. · Place the battery in the instrument as described in the "BATTERY REPLACEMENT" chapter. · Place the instrument on a flat table. · Do not place the instrument under direct sun light. MEASUREMENT PROCEDURE To compensate the meter for the sample turbidity or color, the measurement takes place in two phases. First, the meter is zeroed using the unreacted sample. After the reagents are added the reacted sample is measured. · Turn the meter on by pressing ON/OFF. The display briefly shows all tags on. 12 · When the beeper sounds briefly and the LCD displays dashes, the meter is ready. The blinking "ZERO" indicates that the instrument needs to be zeroed first. · Fill a graduated beaker with 50 mL of sample. · Add 0. 5 mL of HI 93719A-0 Magnesium indicator solution, then swirl to mix. · In the same beaker add 0. 5 mL of HI 93719B-0 Alkali solution for Magnesium, then swirl to mix. · Fill two cuvettes with 10 mL of sample each. · Add 1 drop of HI 93719C-0 EDTA solution to one cuvette, replace the cap and swirl the solution. · Add 1 drop of HI 93719D-0 EGTA solution to the second cuvette, replace the cap and swirl the solution. · Place the blank into the cuvette holder and ensure that the notch on the cap is positioned securely into the groove. · Press ZERO/CFM and the lamp, cuvette and detector icons will appear on the display, depending on the measurement phase. [. . . ] If a valid measurement was displayed before auto-shut off, the value is displayed when the instrument is switched on. The blinking "ZERO" means that a new zero has to be performed. One fresh battery lasts for around 750 measurements, depending on the light level. The remaining battery capacity is evaluated at the instrument startup and after each measurement. [. . . ]