Certified Respiratory Therapist Practice Exam

What is the first corrective action if a fuel cell oxygen analyzer reads 18% in ambient air?

1. Replace the sensor immediately

2. Calibrate the sensor

3. Check for leaks

4. Clean the electrode

The correct answer is: Calibrate the sensor

When a fuel cell oxygen analyzer reads 18% in ambient air, which should typically show approximately 21% oxygen, the first corrective action to take is to calibrate the sensor. Calibration is essential because it ensures the analyzer is providing accurate readings based on established standards. An 18% reading indicates that the device may not be functioning properly, but calibration helps ascertain the accuracy of the readings. Calibration allows the technician to adjust the analyzer to account for any discrepancies from the expected measurement, ensuring reliable performance in future measurements. It's a standard procedure for gas analyzers to validate their readings by using known concentrations of gases to fine-tune their accuracy. Regular calibration also helps maintain the longevity and precision of the equipment. While options like replacing the sensor, checking for leaks, or cleaning the electrode may be necessary at some point, they are more involved responses. These actions typically follow calibration if further issues persist, as they investigate more significant problems rather than addressing the immediate calibration needs first.