In a low-oxygen environment, which factor most directly affects sensor readings?

• A. Ambient humidity
• B. Battery level
• C. Oxygen deficiency
• D. Ambient temperature

Answer: (C)

In sensors that measure oxygen, the output directly tracks how much oxygen is present—the concentration or partial pressure of O2 in the surrounding environment. When oxygen is deficient, there is simply less of the target gas for the sensor to detect, so the reading drops accordingly. The other factors can influence readings in less direct ways: humidity or temperature can alter sensor chemistry or diffusion, and battery level can limit the device’s performance, but they don’t reflect the actual oxygen content as directly as the amount of oxygen available does. So, the oxygen deficiency itself is the primary driver of the sensor reading in a low-oxygen environment.