MEASURING OF AIR. 



447 



Total m.m. 131 397 

 Total Inches 5.16 15.63 



■5.39 



TABLE \1I. (f) 

 Stimmarv of Pressure Drops across Orifices. 



The pressures at the discharge orifice have been measured 

 with a standard spring pressure gauge, which was compared 

 with a dead weight (Crosby) tester. It is presumed that these 

 dead weights (masses) give the correct pressure at the standard 

 value of g and, therefore, the indicators of such an instrument 

 have to be corrected by multiplying by the ratio of local g and 

 standard g. 



Tables VIII a to VTII e give the statement of the observ- 

 ations and the reduction to pounds per sq. inch absolute at 

 the standard value of g. The pressure at the terminus of the 

 compressor and at the orifice would in the ordinary working 

 only differ by a small amount. On the test part of the regula- 

 tion was done at the valve between the two, so that by dropping 

 the density of the air at the orifice, nearly the same orifice head 

 was dbtained at all loads. 



