08湿度传感器系统毕业论文中英文资料外文翻译文献 (1).docVIP

湿度传感器系统 中英文资料外文翻译文献 英文: The right design for a relative humidity sensor system Optimizing the response characteristics and accuracy of a humidity sensor system 1 Overview To make the right choice when selecting a relative humidity sensor for an application, it is important to know and to be able to judge the deciding factors. In addition to long-term stability, which is a measure on how much a sensor changes its properties over time, these factors also include the measurement accuracy and the response characteristics of the sensor. Capacitive humidity sensors are based on the principle that a humidity-sensitive polymer absorbs or releases moisture as a function of the relative ambient humidity. Because this method is only a spot measurement at the sensor location, and usually the humidity of the surroundings is the desired quantity, the sensor must be brought into moisture equilibrium with the surroundings to obtain a precise measurement value. This process is realized by various transport phenomena (cf. the section titled The housing effect on the response time), which exhibit a time constant. Accuracy and response time are thus closely dependent on each other, and the design of a humidity measurement system becomes a challenge. Measurement accuracy The term measurement accuracy of a humidity sensor is understood primarily to refer to the deviation of the value measured by the sensor from the actual humidity. To determine the measurement accuracy, references, such as chilled mirror hygrometers, whose own tolerance must be taken into account, are used. In addition to this trivial component, humidity sensors require a given time for reaching stable humidity and temperature equilibrium (the humidity is a function of temperature and decreases with increasing temperature; a difference between sensor and ambient temperature leads to measurement errors). This response time thus has a significant effect on the value measured by the sensor and thus on the deter