User manual HANNA INSTRUMENTS HI 98202

[. . . ] pNa HI98202 Soft Water Tester GENERAL INFORMATION: The pNa tester utilizes a sodium ion-selective electrode to determine the activity of free sodium in solution. pNa = -log aNa In dilute solutions, the activity coefficient is nearly 1 and in such solutions pNa is a good indicator of the sodium ion concentration. [. . . ] · After use, switch the meter off and rinse the electrode with water to minimize contamination. · Large differences in pNa readings (±0. 5 pNa) could be due to a dry electrode or lack in calibration. · To improve performance, immerse the meter in HI7080 solution up to the maximum immersion level at least once a week. Manufacturers since 1978 pNa HI98202 Soft Water Tester SPECIFICATIONS: RANGE 0. 0 3. 0 pNa (23 0. 023 g/L Na+) RESOLUTION 0. 1 pNa ACCURACY (@20°C/68°F) ±0. 2 pNa TYPICAL EMC DEVIATION ±0. 1 pNa ENVIRONMENT 0 to 50 C (32 to 122 F); 95% RH BATTERY TYPE 4 x 1. 5V alkaline (included) BATTERY LIFE approx. 800 hours of continuous use DIMENSIONS 175x41x23 mm (7. 9x1. 8x1") WEIGHT 78 g (2. 7 oz. ) CALIBRATION: · Immerse the tester in HI7080 calibration solution, without exceeding the maximum immersion level. · Allow the reading to stabilize and with a small screwdriver turn the calibration trimmer until the display shows "1. 0" pNa. MAINTENANCE: In case of erroneous reading even after an accurate calibration, the reference junction can be contaminated or clogged. Pull out 2 mm (1/8'') of the cloth junction to renew the electrode reference (it is recommended to cut the cloth leaving always at least 2 mm -1/8'' over the reference compartment) and repeat the calibration procedure. After that, the electrode can be replaced (see the Electrode Replacement section). BATTERY REPLACEMENT: If display fades or the pNa switches off, the batteries must be replaced. Slide off the battery compartment cover and replace all four 1. 5V batteries while paying attention to their polarity. The internal circuit is connected to the electrode trough two wires (one for the glass sensor and one for the reference). Remove the two small screws (2 & 3) which fasten the two connecting wires to their sockets. · Remove the electrode and replace it with a new HI73202. ACCESSORIES: HI 7080L 2. 3 g/L Na solution (460 mL bottle) HI 7080M 2. 3 g/L Na solution (230 mL bottle) HI 7061M Electrode cleaning solution (230 mL bottle) HI 73202 Spare electrode HI 731326 Calibration screwdriver (20 pcs) Internal circuit: ONE YEAR WARRANTY AND SERVICEABLE: Covered by one year warranty against defects in workmanship and materials, this tester is now completely serviceable. [. . . ] Make sure they are placed properly before reinserting the circuit into the plastic casing. · Reinsert the internal circuit complete with the new electrode into the plastic casing. [. . . ]