Low cost virtual instrumentation using pc printer port for ultrasonic velocity measurements

The most popular and effective technique for ultrasonic velocity measurements is the pulse technique. In the present work, PC based single-pulse sender/receiver system is developed using indigenous components and the bi-directional printer port. A program written in C, under the DOS/WINDOWS environment, controls the pulse generation, detection and travel time measurement. A radio frequency burst of 2 MHz of 5 µs width is obtained from an external source. This pulse is amplified and sent to the transmitting transducer. The received pulse is detected and is used to stop the counter. The number of pulses is counted using a 32 MHz external crystal source. The count is read by printer port and is further used in determining the travel time and to display the ultrasonic velocity of propagation in the medium on the computer screen. The system developed has been tested for ultrasonic velocity measurements in standard liquids. It has been found that the ultrasonic velocity measurement results obtained using the above system match well with those reported in the literature.