Automatic adjusting system and method for ultrasonic signal of gas ultrasonic flowmeter

Abstract

The invention discloses an automatic ultrasonic signal adjusting system and method for a gas ultrasonic flowmeter, which are applied to the technical field of gas flow instruments and comprise a microprocessor, a voltage-adjustable DC-DC (Direct Current-Direct Current), an excitation circuit, a switching circuit, a first transducer, a second transducer, a gain-adjustable amplifier, a signal peak detection circuit and a comparator. On one hand, the excitation voltage is adjusted according to the signal amplitude of the received wave amplified by the amplifier and the gain value of the amplifier, so that the intensities of the excitation wave and the received wave are adjusted, the moderate gain of the amplifier is ensured, the amplified signal is not distorted and has a relatively high signal-to-noise ratio, the accurate zero-cross detection is ensured, and the possibility of wave hopping is reduced; the accuracy and the reliability of flow measurement are improved; on the other hand, excitation voltage is reduced as much as possible on the premise of ensuring moderate amplifier gain, so that power consumption is reduced, and the service life of a battery is prolonged.

Description

technical field [0001] The invention relates to the technical field of gas flow meters, in particular to a system and method for automatically adjusting ultrasonic signals of a gas ultrasonic flow meter. Background technique [0002] Gas ultrasonic flowmeters are more and more favored by users because of their advantages such as wide flow range, no rotating parts, less maintenance, and small pressure loss. Gas ultrasonic flowmeters for urban gas metering generally require internal battery power supply. The power consumption is low, so the time difference method based on zero-crossing detection is mostly used as the measurement principle. When the ultrasonic waves pass through different types of gases with different temperatures and pressures, the energy attenuation degree is very different. If the same excitation voltage is used, the signal amplitude of the received wave is very different under different medium conditions. [0003] At present, the gas ultrasonic flowmeters ...

AI Technical Summary

Problems solved by technology

[0003] At present, the gas ultrasonic flowmeters on the market all use a fixed excitation voltage, and only adjust the amplifier gain to achieve the expected signal amplitude to meet the needs of zero-crossing detection. The measurement reliability is low, the requirements for the measured medium conditions are high, and the medium adaptability is poor

At the same time, the power consumption is large and the battery life is short

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