TISSOT APPARATUS WITHOUT AUTOMATIC COUNTERPOISE. 



225 



From the results of these comparisons it may be seen that with the 

 Tissot 200-liter spirometer, with a pressure on the air inside the bell 

 varying from +0.4 mm. to 0.4 mm. of water, it is not necessary to 

 counterpoise the spirometer bell exactly and automatically by the use 

 of water in the counterpoise tube. These variations in pressure are 

 too small to affect the respiratory exchange. 



TABLE 42. Variations of average results obtained without automatic counterpoise from those 

 obtained with automatic counterpoise Tissot apparatus. 



CARBON DIOXIK ELIMINMED- 



OXYGEN ABSORBED 



RESPIRATORY OUOTIENT- 



RISPIRATIOM RATE- 



- TOTAL VENTILATION VOLUME FtR RESPIRATI 



9SE 



WITHOUT AUTOMATIC 

 COUNTERPOISE 



fib 



t 



V 



V 



\ 



V 





^ 





6 7 8 9 10 I I I a 13 14 15 I 2 3 4 5 6 7 8 9 10 II 12 r3 |4 15 



PER CENT OF VARIATION 



FIG. 74. Probability curves for the series of comparison experiments with and without the 



counterpoise on the Tissot spirometer. 



The ordinates indicate the percentage of the total number of periods and the abscissa? repre- 

 sent the percentage of variation from the average. 



