If calibration results for a spirometer using a 3.0 L syringe show a maximum variance outside 2.85 L - 3.15 L, what does this indicate?

When calibration results for a spirometer using a 3.0 L syringe show a maximum variance outside the range of 2.85 L to 3.15 L, this indicates inaccurate measurement. The purpose of calibration is to ensure that the spirometer provides accurate measurements of lung volumes.

The expected range for a properly calibrated spirometer when using a 3.0 L syringe is very specific; it should fall within ±5% of the target volume, which translates to 2.85 L to 3.15 L for a 3.0 L syringe. If the calibration results fall outside this range, it signifies that the spirometer is not giving reliable readings and may be underestimating or overestimating the lung volumes.

Inaccurate measurement can lead to misdiagnosis or inappropriate treatment decisions, as clinicians rely on accurate spirometric values when assessing respiratory function and making decisions on patient care. Therefore, the indication of inaccurate measurement is critical for maintaining quality and safety in respiratory assessments.