外文翻译1

An Automatic Measuring System Based on Atmospherical Measurement Used for Temperature Relay For temperature relay, it is very important to measure its temperatures for action and reversion. In this paper, anautomatic measuring system based on atmospherical measurement is discussed, which is very simple and precise in practical application. In atmospherical measurement, it is crucial to design a favorable temperaturefield. The resistance stove is designed for simulating temperature field. The even temperature is improved bylong-time warm-up and placing orifice-board in testing room. According to the enactment controlling temperature curve, the algorithm of fuzzy control is used to control the temperature in temperature field. The regulating voltage mode of double-direction Bi-directional thyristors is used for controlling temperature. The system consists of the console and the resistance stove，and the console includes software platform and hardware platform. In this system, The method of grouping the resistance wire of resistance stove according to the power is put forward, and the performance of resistance stove is improved based on this method. The measuring precision is improved by using the minimum two-multiplication to calibrate the error. At present, the system has been practically applied in manufacture, which has gained obvious economy benefit and will be widely applied in the future.

1. Introduction

The temperature relay is one of common relays, which takes action when the outside temperature arrives at the given temperature. The temperature relay performs lots of functions, such as temperature control, fire alarm, automatic ignition, wiring heat-protection, so it is widely used in scientific research, industry and defense industry etc. For temperature relay, it is very important to measure its temperatures for action and reversion. But in the current manufacture, the manual measuring methods, such as spot-check method, mercuric thermometer method etc, dominate the measuring methods. However there are some inescapable short comings in these methods, such as low efficiency, large labor intensity and bad precision etc. Thus

measurement has become the bottleneck of the quality of temperature relay. With the perpetual progress in the technology, the need for product quality gets more and more strict and the degree in manufacture automatization gets more and more deep. For temperature relay, today the manual measuring methods have become unfitted for the need for manufacture and will be necessarily replaced by the automatic measuring methods. In this paper, an automatic measuring system based on atmospherical measurement is discussed, which is very simple and precise in practical application.

2. Measuring principie

Two kinds of metals whose inflated coefficient make a great deal of difference are hard composed together, and then the dishing twin-sheet metal comes into being.When the temperature relay arrives at a certain given value, one upward curving force will come into being in twin-sheet metal as a result of big expanding for nether metal and small expanding for upper metal. When the twin-sheet metal bends at a certain extent, it will drive the electric contact and switch on or switch off the circuit. When the temperature relay reduces at a certain given value, the twin-sheet metal gradually involutes. When the twin-sheet metal resumes at a certain extent, it will 3rd International Symposium on Instrumentation Science and Technology Aug. 18~22, 2004, Xi’an. China drive the electric contact in inverse direction and switch on or switch off the circuit. The working principle of dishing twin-sheet metal is described as Fig1:1-the initiatory state(room temperature), 2-the state after heated or cooled, 3-displacement.

The temperature relay takes action due to the rising of ambience temperature or the heating of passing current.The resistance of relay is very small. So compared with the temperature rising caused by ambience temperature, the temperature rising caused by current heating also is very small and can be ignored. Thus measuring temperatures for action and reversion is implemented by controlling the environment temperature. There are three methods for measuring temperatures for action and reversion, which are liquid measurement, atmospherical measurement and testing-block measurement in GJB1517-92.