Abstract: A transmission measuring system includes a subject for transmission measurement for outputting, in response to a start signal for measurement from a central processing unit, an output signal including information on a transmission time to be measured. An analog-digital converter converts the output signal into digital data. The central processing unit processes the digital data to obtain the transmission time required for propagating the signal through the subject. A clock signal source provides a clock signal to the central processing unit, and a variable delay unit is interposed between the clock signal source and the analog-digital converter. The central processing unit delivers a delay time control signal to the variable delay unit so that the delay time of the clock signal of the analog-digital converter may be varied with time relative to the start signal for measurement.

Abstract: To provide an industrially advantageous transmission measuring system of sufficiently high time resolution, i. e. the system that can make measurement in high accuracy without using expensive analog-digital converter.

Abstract: A transit-time difference type ultrasonic flowmeter comprises a pair of ultrasonic transducers mounted on a flow tube at an upstream side and a downstream side respectively, a switching device for switching the operational mode of each of the transducers alternatively to its transmitting or receiving mode, an amplifier for amplifying the signal received by the transducer of the receiving side, and a data reduction equipment includes an analog-digital converter and a digital signal processor; the converter converts the waveform into a plurality of voltage-time data sets; and the processor picks up an object peak of the voltage-time data sets on the basis of the time, or the data on the voltage, or determines the peaks of maximum voltage included within the waveform of the voltage-time data sets as an object peak, estimates at least one zero-cross point confined by the object peak or a peak adjacent to the object peak through the calculation made on the plurality of voltage-time data sets distributing along the

Abstract: The amplifying gain is controlled by means of a data reduction equipment on the basis of the control signal input into the amplifier for amplifying the received signal propagated through the fluid and received in the ultrasonic transducer in the receiving side. The data reduction equipment includes an analog-digital converter, a processor, and a memory, wherein converted into digital data are waveform data including a peak value of each of the received signals, and the obtained digital data are stored in the memory.

Abstract: The amplifying gain is controlled by means of a data reduction equipment on the basis of the control signal input into the amplifier for amplifying the received signal propagated through the fluid and received in the ultrasonic transducer in the receiving side. The data reduction equipment includes an analog-digital converter, a processor, and a memory, wherein converted into digital data are waveform data including a peak value of each of the received signals, and the obtained digital data are stored in the memory.

Abstract: A transit-time difference type ultrasonic flowmeter comprises a pair of ultrasonic transducers mounted on a flow tube at an upstream side and a downstream side respectively, a switching device for switching the operational mode of each of the transducers alternatively to its transmitting or receiving mode, an amplifier for amplifying the signal received by the transducer of the receiving side, and a data reduction equipment includes an analog-digital converter and a digital signal processor; the converter converts the waveform into a plurality of voltage-time data sets; and the processor picks up an object peak of the voltage-time data sets on the basis of the time, or the data on the voltage, or determines the peaks of maximum voltage included within the waveform of the voltage-time data sets as an object peak, estimates at least one zero-cross point confined by the object peak or a peak adjacent to the object peak through the calculation made on the plurality of voltage-time data sets distributing along the