User manual HANNA INSTRUMENTS HI 4113

[. . . ] This organic ion exchanger is considered a carrier ionophore in that it is capable of shielding and carrying the charged nitrate ion in it's polar cage freely through the apolar regions of the membrane. A charge imbalance developes between the test solution and internal cell of the sensor. When the ionic strength of the sample is fixed, the voltage is proportional to the concentration of nitrate ions in solution. The sensor follows the Nernst Equation: E = Ea + 2. 3 RT/nF log A ion E = observed potential Ea = Reference and fixed internal voltages R = gas constant (8. 314 J/K Mol) n = Charge on ion (-1) A ion= ion activity in sample T = absolute temperature in K F = Faraday constant (9. 648 x 104 C/equivalent) 3 IV. [. . . ] Drain electrode, disassemble and rinse internal body with deionized water. · If an erratic measurement occurs, check to see if foreign matter is seen trapped near the internal cone. Drain by depressing the electrode cap then refill with fresh fill solution. VIII. Electrode VIII. Electrode Preparation HI 4013 The Hanna HI 4013 is a 2 piece design comprised of a sensor handle (HI 4000-50) and a sensing module (HI 4013-51). Do not touch the sensing membrane with the "H" hole pattern on it. Holding the assembled electrode at the cable end, shake the sensor to ensure internal fill solution that may have separated during shipping is in contact with inner membrane surface. Prepare HI 5315 reference electrode by filling electrolyte reservoir with HI 7078 fill solution. Place sensor and reference electrodes into electrode holder and connect cable connectors to meter. Soak the Nitrate electrodes membrane in a Nitrate containing standard (0. 001M) without ISA before calibration. Unwrap Parafilm® seal found over ceramic junction on inner stem and discard. Do not touch the sensing membrane with the "H" hole pattern on it. Do not over tighten. 8 Deionized Water Remove Parafilm Install sensing module 4. Rinse inner stem with deionized water making certain to wet o-ring found on the inner stem. Reassemble electrode by gently pushing the inner assembly into the outer body, sliding spring down cable, and screwing cap into place. Using the dropper pipette provided, add a few drops HI 7078 fill solution to the electrode. Invert the electrode to wet the o-ring and rinse the fill solution chamber. 9 7. Holding the body of the electrode gently press upper cap with your thumb. Tighten the electrode cap onto the body and fill electrode body until fill solution volume is just below fill hole. Position electrode in a Hanna HI 76404 electrode holder (or equivalent) and connect BNC connector to meter. · · · · · · Quick Check of Electrode Slope Connect electrode(s) to pH/mV/ISE meter Place meter in mV mode. Place reference and measuring half-cell or combination electrode into prepared sample. Record the mV when reading has 10 HI 4113 E NITRAT TION NA COMBI stabilized. [. . . ] Storage and Care of the HI 4013 and HI 4113 electrodes The HI 4013 sensor can be stored in standards that do not contain ISA for short time periods. For long term storage, unscrew sensing module from sensor handle and store dry in the shipping vial. The model HI 4113 combination electrode can be left in dilute standards that do not contain ISA for short time periods. If the electrode will be used frequently and needs to be ready for use, take measures to prevent evaporation of fill solution. [. . . ]