摘要
介绍了用集成锁相环路解码器LM567作为超声波检测元件,以89C51单片机作为主控元件的超声波液位测量的原理、电路及测控程序。用超声波测量液位具有不与被测介质接触、可测量低温介质、无可动部件、寿命长等优点;以LM567作为超声波检测元件可降低系统的价格,提高超声波捕捉能力;采用单片机来控制超声波的发射与接收,并且计算出液位,使检测具有更高的智能性。对由于超声波声速变化及LM567输出延时引起测量误差的原因作了详细的分析,并提出了提高调整波速精度及调整输出延时的措施。实验表明:该液位测量仪具有较高的准确度和可靠性,并且价格低廉,具有广泛的用途。
The theory,the circuit,and the program were introduced using LM567 as the component to detect the ultrasonic and using the MCU 89C51 as the main control component.The advantages of keeping clear of the medium which is detected,being likely to detect low temperature medium,no movable component,longevity and so on can be obtained when using the ultrasonic to detect the liquid-level.The system's price can be reduced and the ability to catch the ultrasonic can be improved with LM567 as the detecting component of the ultrasonic.The more intelligent can be obtained when using the MCU to control the emission and receive and to calculate the liquid-level.The causes by the ultrasonic velocity's variety and the delay of the LM567's output to bring the measuring errors were analyzd in detail and the method to reduce it is by hieghtening the precision when adjusting the ultrasonic velocity and the delay was also put forward.This meter has a highly accuracy,credibility and by the experiment,and it can be used widely in many aspects.
出处
《仪表技术与传感器》
CSCD
北大核心
2004年第6期8-9,14,共3页
Instrument Technique and Sensor
