Xll 



CONTENTS 



1-23. Capacitive Transducers 



(a) Change-of -distance Systems 



(b) Change-of -area Systems 

 1-24. Thermal, Displacement Transducers 



(a) Bolometer Systems 



(b) Positio7i Convectron 

 1-25. Piezoelectric Transducers . 

 1-26. Miscellaneous Transducer Systems 



(a) Vibrating -string Transducer 



(b) Electronic Displacement Transducers 



(c) Ionization Transducer 



(d) Mechanic-Optical Transducers 

 1-3. Transducers for Velocity or Acceleration . 



(a) Differentiating Systems 



(b) Induction Transducers 



(c) Separate Measurements of As and At 

 1-4. Liquid-level Transducers .... 



1-41. Resistive Methods 



(a) Contact Systems 



(b) Electrolytic Resistance 

 1-42. Inductive Method 

 1-43. Capacitive Methods 



(a) Direct Capacitance 



(b) Electrode-to- Liquid Surface Capacitance 

 1-44. Thermal Method .... 



1-5. Pressure Transducers .... 

 1-51. Resistive Pressure Transducer 

 1-52. Capacitive Pressure Transducers 

 1-53. Piezoelectric Pressure Transducer 

 1-54. Electrokinetic Pressure Transducer 

 1-55. Pressure Transducers Based upon Electric Gas Dis 



charges .... 



1-56. Thermal Gauges . 

 1-57. Ionization Gauges 



(a) Thermionic Gauge 



(b) Radioactive Ionization Gauge 



(c) Philips-Penning Ionization Gauge 

 1-6. Transducers Responding to Flow Velocity of Liquids 



1-61. Resistive Transducer Systems for Liquid Flow Ve 

 locity ...... 



(a) Electrolytic-tracer Method 



(b) Electrolytic-dilution Method 

 1-62. Liquid flow Induction Transducer 

 1-63. Thermal-flow-velocity Transducer 

 1-64. Sonic Method .... 

 1-65. Radioactive -tracer Methods 

 1-66. Transducers Responding to Gas Flow Velocity 



Thermal Systems . 



(a) Thomas Method. 



(b) Hot-wire Probe . 



66 

 66 

 69 

 72 

 72 

 73 

 74 

 83 

 83 

 85 

 86 

 89 

 91 

 91 

 92 

 93 

 95 

 95 

 95 

 96 

 97 

 98 

 98 

 99 

 100 

 101 

 102 

 104 

 105 

 106 



108 

 109 

 112 

 112 

 114 

 116 

 117 



118 

 118 

 120 

 120 

 123 

 125 

 126 



127 

 127 

 129 



