M. Greenspan and C. E. Tschiegg 
TABLE 5.1. Calibration of Laboratory 
Velocimeters 
Model TR-2(NBS) 
Circuit type transistor 
Path invar steel (316) 
No. of points 57 9 
Temperature extremes, °C 0.8 to 83.2 0.6 to 50.4 
Effective length, 1 
Value, cm 14.6941 20.4848 
St. dev., cm 0.0010 0.0068 
Time delay, ¢t, 
Value, sec 0.7188 0.3713 
St. dev., psec 0.0004 0.0464 
Std. dev. of 1/ f data 
psec 0.0018 0.0045 
ppm 18 32 
Std. dev. of prediction ppm 2.4 11 
97 
Fig. 5.8. Transducer mounts for the sound head of Fig. 7. 
