How long after calibration are PO2 readings noted?

• A. 15-20 minutes
• B. 1-2 minutes
• C. 30-40 minutes
• D. 5-10 minutes

Answer: (A)

Stabilization time is required for the PO2 sensor to reach a steady, accurate reading after calibration. When you calibrate, the device sets a reference based on known gas values and the sensor’s electronics begin re-equilibrating with those conditions. The sensor can take several minutes to warm up and for the membranes, chemical reactions, or optical components to settle so temperature compensation, drift, and response time are correct.

About 15 to 20 minutes allows the system to achieve this stable baseline, minimizing drift and ensuring that subsequent PO2 measurements reflect true gas tension rather than transient sensor effects. Shorter times, like a few minutes, may capture an unstable or drifting signal, while much longer times aren’t typically necessary and would delay measurements.

So, the best practice is to note PO2 readings after a 15–20 minute stabilization period following calibration.