Which factor can lead to unreliable readings in oxygen-deficient environments?

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

Answer: (C)

Oxygen readings from many detectors rely on a chemical reaction that uses ambient oxygen to produce a measurable signal. When the environment is oxygen-deficient, there’s less oxygen available for that reaction, so the sensor’s signal becomes very small, often approaching its noise level, and the response can be slow or drift away from the true value. In short, the lack of oxygen directly undermines the sensor’s ability to generate an accurate, reliable reading, which is why oxygen deficiency itself is the factor that leads to unreliable measurements. Other factors like humidity, battery level, or temperature can affect readings in some cases, but the most direct cause of unreliability in an oxygen-deficient environment is the scarcity of the very species the sensor is designed to measure.