Patient Monitor Calibration 2026: ECG, NIBP, SpO2, Respiration, Invasive Pressure and NABL Requirements Short answer: Patient monitor calibration evaluates individual measurement channels rather than treating the monitor as one generic instrument. NABL 126 identifies heart-rate accuracy, respiration-rate accuracy, NIBP leak, NIBP static pressure, NIBP pressure relief, dynamic NIBP repeatability, SpO2 and invasive pressure within its patient-monitor framework and lists an electrical-safety analyzer plus patient-monitor simulator as reference equipment. In 2026, pulse-oximeter equipment is covered by the new ISO 80601-2-61:2026 Edition 3, while multifunction patient monitors are covered by IEC 80601-2-49:2018+A1:2024. A bedside monitor can display several physiological quantities at the same time, but those channels do not all work on the same measurement principle. ECG heart rate is an electrical-signal measurement. NIBP uses pressure and an algorithm. SpO2 uses optical puls...