1. VENTILATORY FUNCTION TESTS. II. FACTORS AFFECTING THE VOLUNTARY VENTILATION CAPACITY
2. Mica spring exhalation valve (R.M.277) obtainable from Safety and Medical Equipment Co., Johannesburg, South Africa and from Draegerwerk, Luebeck, Germany.
3. Manufactured by Liston-Becker Instrument Co., Inc., Springdale (Stamford), Conn. Model 16.
4. These values represent the characteristics of one sample of each valve type and are not necessarily representative of the type as a whole.