Quality control in the pulmonary function laboratory.

Quality control and proficiency testing are well recognized as means for evaluating equipment accuracy and technical proficiency use of spirometry in physicians' offices, clinics, and industry has brought attention to the need for standardization of calibration and testing techniques in pulmonary function testing. Minimum specifications for equipment accuracy provide the basis for consistency of interlaboratory measurements, and familiarity with operation, calibration, and maintenance procedures enhances personnel proficiency.