Abstract: A calibration system for a flow meter includes a flow simulator, the flow simulator including a receiver configured to receive flow meter transducer signals from a flow meter. A simulation subsystem is configured to create simulated transit time signal pulses, and to transmit the simulated transit time signal pulses to the flow meter at preselected time intervals. A calibration subsystem is configured to receive from the flow meter a transit time differential value generated by the flow meter based on the simulated transit time signal pulses and output a calibration factor to the flow meter.

Abstract: A calibration system for a flow meter includes a flow simulator, the flow simulator including a receiver configured to receive flow meter transducer signals from a flow meter. A simulation subsystem is configured to create simulated transit time signal pulses, and to transmit the simulated transit time signal pulses to the flow meter at preselected time intervals. A calibration subsystem is configured to receive from the flow meter a transit time differential value generated by the flow meter based on the simulated transit time signal pulses and output a calibration factor to the flow meter.

Abstract: A simulating circuit (2), for testing a transit-time flowmeter (1) according to an embodiment of the invention, comprises an interface circuit (20) connecting with the transit-time flowmeter. The interface circuit receives driving signals from the transit-time flowmeter and generates a trigger signal on a rising or falling edge of the driving signals. An oscillator (21) outputs a clock signal. A delay generator (221) generates a preset time delay. A Digital to Analog Converter (DAC, 25) retrieves preset digitalized waveform. The DAC is enabled by the oscillator on ending of the preset time delay and converts the preset digitalized waveform into analog waveform output. The analog waveform output is sent back to the transit-time flowmeter, and thus a transit time or and a waveform through flowing fluids is simulated.

Abstract: An automated method and system for calculating the transit time of a pulsed signal transmitted from a first ultrasonic transducer to a second ultrasonic transducer is provided. The method includes measuring the amplitude of the pulsed signal received at the second transducer from the first transducer; measuring the amplitude of any noise proximate to the received pulsed signal; and calculating the signal to noise ratio of the received pulsed signal and the noise, respectively. If the signal to noise ratio is above a predetermined threshold, a first technique is automatically implemented for calculating the transit time of the received pulsed signal. If the signal to noise ratio is less than the predetermined threshold, a second different technique is automatically implemented for calculating the transit time of the received pulsed signal.

Abstract: An apparatus and method for measuring gas flow velocity through a high stack employs ultrasonic transducers. The transducers are placed on opposite ends of a diameter several hundred feet up, with a small vertical separation L between the transducers. Apparatus for measuring acoustic velocity in the stack gas over short path lengths is also included.