User manual HANNA INSTRUMENTS HI 4115

[. . . ] HI 4115 SILVER/SULFIDE COMBINATION HI 4015 SILVER/SULFIDE Instruction Manual HI 4015 HI 4115 Silver/Sulfide Ion Selective Electrode Half-cell Combination 1 HI 4015 Silver/ Sulfide Half-cell HI 4115 Silver/ Sulfide Combination Electrode I. Introduction: The Hanna HI 4015 and HI 4115 are ion selective electrodes designed for the measurement of Silver/ Sulfide ions in aqueous solutions. The HI 4015 is a solid state half-cell sensor that requires a separate reference. The HI 4115 is a combination ion selective electrode. [. . . ] · Place electrode (s) into prepared sample. · Add 1 mL of a standard (0. 1 M or 1078. 7 ppm standard) to beaker. · Add an additional 10 mL of standard to the solution. Record the mV when reading has stabilized. This value should greater than the previous noted (more positive). · Determine the difference between the two mV values. An acceptable value for this slope is 56 ± 4 mV. If sensor does not have appropriate mV change, corrective action must be taken. S 2· Connect sensors to pH/mV/ISE meter. · Place 50 mL of deareated water into a beaker with 50 mL of the premixed SAOB, Hanna HI 4015-00. · Place electrode (s) into prepared sample. · Add 1 mL of the titrated standard to beaker. · Add an additional 10 mL of standard to the solution. Record the mV when reading has stabilized. This value should less than the previous noted (more negative). · Determine the difference between the two mV values. An acceptable value for this slope is -28± 4 mV for freshly made solution. Solution exposed to air will be degraded and lower slopes will be observed. If sensor does not have appropriate mV change, corrective action must be taken. 10 X. Corrective action · Verify protective cap has been removed. (HI 4015) · Verify plastic film has been removed from inner stem. (HI 4115) · Verify electrodes are connected properly to meter and meter is powered. · Verify dilute standards are freshly made and stored. · Verify SAOB was added to sulfide standards and they have been stored appropriately. [. . . ] During the titration the sensor follows the decrease in the halide concentration while small additions of silver nitrate titrant are added. The silver reacts with the chloride ions forming a precipitate of silver chloride. At the stoichiometric end point, a large change in mV occurs as the silver is in excess. Measurements may be automated by use of the Hanna Titrator HI 901 or titrated manually. [. . . ]