When calibrating a gas meter, which reading would you expect for oxygen?

When calibrating a gas meter, which reading would you expect for oxygen?

• A. 100%
• B. 0%
• C. 50%
• D. 75%

Answer: (A)

When calibrating a gas meter, you set the instrument against a known reference concentration so its readings match that value. For oxygen, the reference is pure oxygen, which marks the top end of the scale. Exposing the sensor to oxygen gas should drive the reading to 100% oxygen, establishing the maximum on the instrument. The other options would only occur if you were using a gas with less than full oxygen content or performing a different calibration step, not the full-scale oxygen calibration. So the expected reading is 100%.

When calibrating a gas meter, you set the instrument against a known reference concentration so its readings match that value. For oxygen, the reference is pure oxygen, which marks the top end of the scale. Exposing the sensor to oxygen gas should drive the reading to 100% oxygen, establishing the maximum on the instrument. The other options would only occur if you were using a gas with less than full oxygen content or performing a different calibration step, not the full-scale oxygen calibration. So the expected reading is 100%.