575 
LOTTE 
<— TMB 9078 
Figure 2 - Three Stages in the Evolution of the TMB Quartz Pressure Gage 
A is an early model with plastic mount; 
B is a double-crystal model with brass mount; and 
C is a single-crystal model, shown in greater detail in Figure 3. 
All three of the gages are reproduced here in approximately their natural size. 
to one electrode on the quartz; the other side of the crystal is groundéd to 
the mount. The brass tube is soldered to a long copper tube which serves as 
a cable. 
The sensitivity of the pickup is determined by the area of the crys- 
tal and its total capacitance, the distributed cable capacitance, and any 
lumped capacitance that may be added. The output of the quartz crystal used 
is approximately 
