577 
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A. acne ee | 
Housing 
Top View 
SING Ones 
Figure 4 - Modification of Quartz Gage for Attachment to a Surface 
A nut is soldered to the bottom of the housing, and a threaded stud is soldered 
to the surface at which the pressure is to be measured. 
The brass housing of the quartz gage lends it great durability, and 
thus the gage will last for a very large number of explosions. This advan- 
tage is offset by the vibrations set up in the quartz mount when the gage is 
subjected to explosions. The observed frequency of the mount is of the order 
of 7 x 10* cycles per second, not high enough to prevent the introduction of 
an error in the determination of the peak pressure. A quartz gage of modi- 
fied design which should possess a considerably higher natural frequency is 
under construction at the Taylor Model Basin. 
The quartz mount can be readily adapted to the measurement of ex- 
plosion pressures at the surface of an underwater structure. This is accom- 
plished by silver-soldering a nut to the bottom of the mount, and attaching a 
threaded stud to the surface in question; see Figure 4. 
THE TMB TOURMALINE GAGE 
The TMB form of tourmaline pressure gage differs from the one devel- 
oped by the Underwater Explosives Research Laboratory at Woods Hole chiefly 
