传感技术学报2019，Vol.32Issue(1)：36-42,7.DOI:10.3969/j.issn.1004-1699.2019.01.007
阻抗匹配抑制时差式气体超声波流量计零漂
Restraining Zero Drift of Time-Difference Gas Ultrasonic Flowmeter by Impedance Matching
郑晓宇 1杨鸣 1金定飞 2聂西利3
作者信息
- 1. 宁波大学信息科学与工程学院, 浙江 宁波 315211
- 2. 浙江天信超声技术有限公司, 杭州 310016
- 3. 金卡高科技股份有限公司, 杭州 310016
- 折叠
摘要
Abstract
In flow measurement the zero drift of time-difference ultrasonic gas flowmeter would be too high, decreasing measurement accuracy of the whole system. Aiming at this occurrence, a method that restrains zero drift by matching the input impedance of sensor in transmitting state and the output impedance of the same sensor in receiving state in the channel is proposed. Use chip capacitors to raise the impedance of signal stimulation port, disengaging it from virtual ground state. Therefore, preclude the same sensor from circuit structure variation with upstream and downstream swapping. Keep the resonance frequency of the sensor unchanged. So the inherent delay of transmitting-receiving circuit of ultrasonic sensors are equal in upstream and downstream measurement. Utilize cross-correlation method to make the inherent delay in upstream and downstream cancelled out. Practical measurement shows that impedance matching effectively restrains zero drift, and zero error is restrained below 0.000 48 m3/h at 20 ℃, conforming with grade 1.5 Gas Flowmeter National Standard.关键词
气体超声波流量计/零漂/零点误差/阻抗匹配Key words
ultrasonic gas flowmeter/zero drift/zero error/impedance match分类
信息技术与安全科学引用本文复制引用
郑晓宇,杨鸣,金定飞,聂西利..阻抗匹配抑制时差式气体超声波流量计零漂[J].传感技术学报,2019,32(1):36-42,7.
