The Milwaukee ORP 200–275 mV Solution is a lab-grade standard designed to verify and maintain the accuracy of ORP electrodes and meters. Certified to fall within the 200–275 mV range at 25 °C, this 230 mL solution ensures reliable, repeatable readings for water quality applications. The sealed, air-tight, tamper-proof bottle protects the solution from light and contamination, enabling fast on-site battery of ORP systems. Ideal for routine checks in potable water, wastewater, pool maintenance, and industrial treatment, it supports consistent measurement performance.