Pipet 100.0 ± 0.1 mL of potassium permanganate solution and 100 mL of the sulfuric acid solution into a 250-mL beaker. Bring this mixture to 25°C quickly and add it immediately to the disintegrated test specimen, simultaneously starting a stopwatch. Rinse out the beaker, using not more than 5 mL of distilled water, and add the washings to the reaction mixture. The total volume should be 1000 ± 5 mL.