文献翻译——热电偶冷端补偿.doc

外文文献资料
Implementing Cold-pensation in Thermocouple
Applications
Abstract: Thermocouples are one of the most widely used temperature-measurement devices because of their ruggedness, repeatability, and fast response time. This application note discusses the basic operation of a thermocouple, which includes the definition and function of a reference (cold) junction. The note also gives guidelines for selecting a device for cold-junction temperature measurement based on application needs. Three circuit examples are shown.
Introduction
Of the many transducers available for temperature-measurement applications, thermocouples are among the mon. Thermocouples are found in everyday systems such as automobiles and home appliances. They offer a cost-effective means for measuring a much wider range of temperatures than mon solutions like resistance temperature devices (RTDs), thermistors, and temperature-sensing integrated circuits (ICs). In addition, ruggedness, repeatability, and fast response time make thermocouples a popular choice in many environments.
There are, however, some disadvantages to using thermocouples, notably its lack of linearity. Although thermocouples can be used over a wider range of temperatures than RTDs and temperature-sensing ICs, they are far less linear. Also, RTDs and temperature-sensing ICs typically offer better sensitivity and accuracy, two desirable characteristics for more precise applications. Thermocouple signals are very low-level and often require amplification or a high-resolution data converter to process the signals.
Despite the above disadvantages, overall cost, ease of use, and wide temperature range still make thermocouples popular.
Thermocouple Basics
Thermocouples are differential temperature-measurement devices. They are constructed with two wires made from dissimilar metals. One wire is predesignated as the positive side, and the other as the negative. Table 1 lists the four mon thermocouple types, the metals or alloys us