User manual HANNA INSTRUMENTS C 125

[. . . ] If the instrument is to be returned to Hanna Instruments, first obtain a Returned Goods Authorization number from the Customer Service department and then send it with shipping costs prepaid. When shipping any instrument, make sure it is properly packaged for complete protection. TABLE OF CONTENTS Preliminary examination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Principle of operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [. . . ] · The mark on the cuvette cap should point towards the LCD. 8 · Press the READ/ key and the LCD will display a blinking "SIP" (Sampling In Progress). The limpidity value will appear after approximately 25 seconds. SOURCES OF INTERFERENCE · Presence of floating debris and coarse sediment which settle out rapidly will give false readings. · The infrared light source used for C125 limpidity meter can effectively minimize errors due to coloured dissolved substances. This effect, named "true colour", is a common interference for most commercially available instruments operating in the range of visible light. · Air bubbles and the effect of vibrations that disturb the surface of the sample will give false results. · Dirty glassware could also affect readings along with scratched or edged cuvette. 9 CALIBRATION If repeated measurements differ more than an acceptable value, check if the meter calibration status by measuring a standard solution. Anyway, it is recommended to perform a monthly calibration of the meter, or more frequently for greatest accuracy. To check the date of last calibration, press and hold the DATE/ key down for few seconds. CALIBRATION PROCEDURE · Turn the meter on and wait for the display to show "----". · Press the CAL key once, the "CAL" message will blink on the display for about 6 seconds, then the calibration mode stops. · While the "CAL" message is still blinking, press CAL again. The instrument is now in the calibration mode and a "CL" will appear on the lower part of the display. The date of calibration can be edited now by simply pressing the DATE/ key. To scroll to the correct number press the READ/ key. The first blinking parameter is the month, on the left hand of the display (MM. DD). · To confirm the displayed data values and to go to the next step, press the CAL key once. A blinking "ZERO" message will appear. · Fill the measurement cuvette with HI 93703-0 standard (@ ZERO FTU, or turbidity-free water). Note: In order to minimize any error introduced by the cuvette, it is recommended to use the same cuvette during calibration and for measurements. · Insert the cuvette with the ZERO FTU standard solution (or turbidity-free dilution water) into the measurement cell and press the CAL key. 10 "SIP" and "CL" will start blinking. After approximately 50 seconds the instrument will ask for the HI 93703-10 standard solution (10 FTU) by displaying "10. 0". · Fill the cuvette the HI93703-10 standard, insert into the measurement cell and press the CAL key again. [. . . ] (03) 3258. 9565 · Fax (03) 3258. 9567 Korea: Tel. (02) 2278. 5147 · Fax (02) 2264. 1729 Malaysia: Tel. (603) 5638. 9940 · Fax (603) 5638. 9829 Singapore: Tel. 6296. 7118 · Fax 6291. 6906 South Africa: Tel. [. . . ]