User manual HANNA INSTRUMENTS HI 83749

[. . . ] (401) 765. 7500 · Fax (401) 765. 7575 For e-mail contacts and a complete list of Sales and Technical offices, please see www. hannainst. com. Instruction Manual Australia: China: Egypt: Turbidity & Bentocheck HI 83749 Germany: Greece: Indonesia: Japan: Korea: Malaysia: Singapore: South Africa: Taiwan: Thailand: MAN83749R1 11/05 United Kingdom: USA: w w w. c o m 40 1 Dear Customer, Thank you for choosing a Hanna Instruments product. This manual will provide you with the necessary information for correct use of the instrument. Please read this instruction manual carefully before using the instrument. [. . . ] When average or continuous mode is selected, the "NTU" tag blinks for each new displayed value. 7) Four digit secondary display. A long beep indicates an error or an invalid key pressed. 9 GENERAL TIPS FOR AN ACCURATE MEASUREMENT GENERAL TIPS · · · · The instructions listed below should be carefully followed to ensure best accuracy. Always cap the cuvets to avoid spillage of the sample into the instrument. Keep the lid of the instrument closed when it is not used to prevent dust or dirt entering. Put always the instrument on a flat, rugged surface when taking measurements. SET EPA COMPLIANCE MODE When EPA compliance reading is on, "EPA" message is displayed on the secondary LCD and the reported values are rounded to meet EPA reporting requirements. CUVET The cuvet is part of the optical system and measurements can be affected by the glass imperfections, dirt, dust, scratches, or fingerprints present on the cuvet surface. · To edit the EPA mode, press CAL/RCL when EPA compliance reading panel is displayed. · Press the UP or DOWN keys to set the EPA compliance mode on or off. The new selected option of the parameter will be displayed on the LCD. Alternatively, press CAL to exit without saving the new settings. CUVET HANDLING · Any cuvet with visible scratches must be discarded. · Always store the cuvets in separate boxes or with separators between them to avoid scratches on the surface. · Whenever a cuvet is placed into the instrument, it must be dry outside, free of fingerprints or dirt. Wipe it thoroughly with HI 731318 (tissue for wiping cuvets, see Accessories Section, page 39) or a lint-free cloth prior to insertion. or CUVET OILING · For low turbidity readings (<1. 0 NTU) the cuvets should be oiled outside with the supplied HI 93703-58 Silicone Oil. Use only one single drop of oil and then wipe the cuvet thoroughly with a lint-free cloth. SET BEEPER The HI 83749 has a built-in beeper that signals the tag read, the key press and the error conditions. · To set the beeper on or off, press CAL/RCL when set beeper panel is displayed. The beeper status and the CFM tag will start blinking. SAMPLING TECHNIQUE When you make turbidity measurements it is important to take a representative sample. · Samples should be analyzed immediately after collection because turbidity can settle or change in time. · Pay attention when working with cold samples that no condense is formed on the outside of the cuvet. 31 or · Add HI 83749-0 Bentocheck reagent, mix and wait for 1 minute. · If the difference between T1 and T2 is less than 10%, the instrument gives a beep of 1 second and displays alternating the turbidity value (NTU) and the difference (%). · If the difference between T1 and T2 is more than 10%, the instrument just displays T2 in the primary LCD and T1 in the secondary LCD. REMOVING AIR BUBBLES alternated with Air bubbles present in the sample will cause erroneous high turbidity readings. · To remove air bubbles fill the cuvet with wine sample and close the cap tightly. Allow the cuvet to stand for a few minutes and gently invert it several times. [. . . ] Replace the cap and wipe the cuvet thoroughly with a lint-free cloth (see General Tips for an accurate measurements, page 10). The meter continues updating the readings until the "Lamp and Read Status" indicator turns off. · At the end of the measurement, the instrument directly displays turbidity in NTU. · Use the 1000 µL automatic pipette to add exactly 1 mL of HI 83749-0 Bentocheck reagent to the cuvet. [. . . ]