【作者】 肖已文；

【导师】 丁喜波；

【作者基本信息】 哈尔滨理工大学 ， 测试计量技术及仪器， 2005， 硕士

【摘要】 湿度是我们日常生活中经常接触的物理量,湿度的检测需要采用湿度传感器来进行。在我国,各行各业对湿度传感器的需求量很大,但是测试的低效率限制了产量的进一步提高。因此如何解决传感器的自动批量测试问题成为制约生产效率提高的主要因素。本文介绍了电容式湿度传感器复数电压法测量原理,建立了基于DSP技术的湿度传感器复数电压法测量模型,并将此模型应用于电路设计,简化了电路,减少了误差环节,为实现高精度快速测量提供了理论依据。本文设计了湿度传感器的测试系统,使用TMS320LF2407A作为主控器件对硬件电路设计;利用高速SPI接口的D/A芯片MAX5722产生正弦波;利用USB接口芯片PDIUSBD12进行高速USB总线传输;利用数字电子开关CD4051进行多路通道选择设计,增强了系统的灵活性、适应性与扩展性。本系统实现了32路电容式湿度传感器的性能参数电容值(C)和品质因数值(Q)的高精度、高速测量,在对30~100pF的电容性元件进行测量时,其引用误差为0.2%。该系统的实现解决了湿度传感器生产过程中检测误差大和速度慢的问题,也为组建其它类似的检测系统提供了可以借鉴的方法和系统构架。更多还原

【Abstract】 Humidity is a physics quantity that is often encountered in our daily life. The humidity measurement is accomplished by the humidity sensor. In our country, there is a very high demand for humidity sensor in every field. But the low efficiency of the measurement restricts the further growth of the production. Therefore, how to solve the problem of automatic batch measuring becomes the chief factor that restricts the improvement of production efficiency. The paper introduced the measurement theory of capacitive humidity sensor complex number voltage and establishes humidity sensor complex number voltage measure mathematics model based on DSP technology which is used in circuit design to simple the circuit and reduce the error segment. All of these were provided a theory to realization high precision and high speed measurement. The paper designs humidity sensor measure system which uses TMS320LF2407A as the main control device to realize hardware circuit design; using high speed SPI interface D/A chip MAX5722 bring sine wave; uses USB interface chip PDIUSBD12 for high speed bus communication and uses digital electronic switch CD4051 for multi-route channels selection design. They are improved agility, adaptability and expansibility of the system. The system accomplishes the measurement of capacitance(C) and quality factor(Q) of the 32-route capacitive humidity sensor with high speed and high accuracy. In the measurement of 30~100pF capacitance, the quote error is 0.2%. The accomplishment of this system not only solves the problem of high error and low speed in the process of producing humidity sensor but also provides reference of method and system frame for designing similar measure system.更多还原