PRINCIPLES OF NAVAL ENGINEERING 



27.350 



Figure 25-18,— Data Logger Section. 



remote indication. The meter is calibrated in the 

 desired scale (PSI). These meters are in most 

 applications d.c. microammeters. 



The pressure switch type transmitter finds 

 its application in the alarm circuitry on the En- 

 gine Room Console. Herein, at a given high or low 

 pressure, electrical contacts within the switch 

 housing are actuated completing or breaking a 

 circuit and actuating an alarm. 



Level Sensors 



Three types of level sensors are gen- 

 erally employed throughout the system. Since 

 pressure may be a function of level the first 

 two devices used are the two detectors men- 

 tioned under pressure; the pressure-to- current 

 for indication and the pressure switch for 

 alarm. 



646 



