PRINCIPLES OF NAVAL ENGINEERING 



(1) Differential Pressure-to-Current Transmitter 



(2) Pressure-to-Current Transmitter 



(3) Float Switch 



(4) Differential Pressure Switch 



(5) Pressure Switch 



140.92 



Figure 25-20.— Pressure and Level Sensors. 



program contact, controlled by the scanner, sets 

 up the comparison values for the signal as well 

 as any adjustments to the signal required during 

 conversion and scaling. 



If the information is requested and/or the 

 point is in alarm, the A/D converter then trans- 

 fers the values via the Word Distributor (24) to 

 the scaling module. If neither of the previously 

 mentioned conditions exist, the scanner executes 

 branch back and picks up the next address and 

 repeats the process. 



After the information leaves the A/D con- 

 verter it is sent to the scaling module which 

 scales all signals into a zero to 1000 scale. This 

 information is in the form of pulses numbering 

 from zero to 1000 according to the value of the 

 input signal to the A/D converter. The address 

 information is then placed in the necessary reg- 

 isters and along with inputs from the Real Time 

 Clock (40) and Digital Inputs (43) and made ready 

 to be sent to the log Printout Buffer (37) and on 

 to the Typewriter Drive (38) for printing. 



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