论文部分内容阅读
超声波在空气中的传播速度ν=(γRT/μ)~(1/2),其中γ=1.402,R=8.31J/K·mol,μ=29×10~3Kg/mol,T为绝对温度,与摄氏温度t的关系为:T=273+t,所以,ν与T~(1/2)成正比。在超声波测距中,如果不考虑温度的影响,所测量的结果会存在误差,在超声波测距计算中,必须进行温度修正。本文介绍一下利用DS18B20温度传感器测温对超声波在空气中传播速度进行修正的方法。 DS18B20功能 DS18B20可编程温度传感器有3个管脚。GND为接地线,DQ为数据输入、输出接口,通过一个上拉电阻与单片机的I/O口线相连,VD为电源接口,也可由数据线提供电源。外部提供电源范围3.0～5.5V。
The propagation velocity of ultrasonic wave in air ν = (γRT / μ) ~ (1/2), where γ = 1.402, R = 8.31J / K · mol, μ = 29 × 10-3Kg / mol, T is the absolute temperature, And Celsius temperature t as: T = 273 + t, so, ν and T ~ (1/2) is proportional to. In the ultrasonic ranging, if you do not consider the impact of temperature, the measurement results will be error, ultrasonic ranging calculation, temperature correction must be carried out. This article describes the use of DS18B20 temperature sensor temperature ultrasonic propagation velocity in the air to be amended. DS18B20 Features The DS18B20 programmable temperature sensor has 3 pins. GND is the ground line, DQ is the data input and output interface, through a pull-up resistor connected with the MCU I / O port line, VD for the power interface, but also by the data line to provide power. External power supply range of 3.0 ~ 5.5V.