GE PT878GC Manual De Usuario

April 2004

Electronics Package

The TransPort consists of circuits that generate, receive, and 
measure the travel time of the ultrasonic pulses. It also contains a 
microcomputer that controls operation and calculates flow 
measurement parameters. Specific circuits function as follows:

A. TRANSMIT SIGNAL GENERATOR - The transmit signal 

generator, under control of the microcomputer and timing 
circuit, synthesizes the signal that drives the transmitter.

B. TRANSMITTER - The transmitter amplifies the signals from 

the transmit signal generator to a signal that drives the 
transmit transducer.

C. RECEIVER - The receiver amplifies the received signals to a 

level suitable for the data acquisition circuitry.

D. DATA ACQUISITION - The data acquisition circuitry 

digitizes the received signal and stores it in a buffer for 
processing by the microcomputer.

E. TIMING CIRCUIT - The timing circuit generates the 

transmitter frequency, receive window, controls the data 
acquisition circuit and the direction of the transmission.

F.  MICROCOMPUTER - The microcomputer controls the 

TransPort flowmeter’s operation and calculates flow 
measurements derived from the transmitted and digitized 
received signals. Also, the microcomputer continually checks 
for faults and allows the use of built-in diagnostics for 
troubleshooting.

G.  INPUT/OUTPUT - The input/output circuitry allows the 

flowmeter to indicate the measured flow with the 
0/4 to 20-mA current loop, and to output to a printer or other 
remote device.