Answer :
Final answer:
A low gas reading could be due to various issues such as improper calibration of the monitor, cracks or leaks in the sample line, or a faulty water trap or filter. The option regarding the exhaust port being calibrated is irrelevant to the cause of a low reading.Option A is the correct answer.
Explanation:
If a student observes that only one gas reading is low, there are multiple possible reasons for this occurrence. One reason, suspect that the monitor is not properly calibrated, suggests that the device used to measure the gas concentration might be giving inaccurate results due to the lack of a recent or proper calibration.
Another possibility could be a crack on the sample line or a leak in the sample line, which could cause the gas to escape before being measured. Also, problems could arise from the water trap or filter is leaking, implying that the gas might be mixing with the air or contaminants due to faulty equipment.
The last provided option, that the exhaust port is calibrated, does not seem relevant to the situation as it does not pertain to an actual malfunction that could lead to a low reading of gas concentration. It should be noted that under normal conditions, the gas is not leaking out, and the cylinder does not change size; thus, a low reading would likely indicate a measurement or equipment issue rather than a physical change in the gas sample volume.
