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1、制冷空调专业英语,Unit Two,Lesson 5 Fluid Lesson 6 Level Measurement Lesson 7 Measuring Rate of Fluid Flow Lesson 8 What Is Humidity,New Words & Expressions Text Notes to the Text Exercise,Lesson 6 Level Measurement,New Words & Expressions,Lesson 6,confuse vt.,搞乱, 使糊涂,unconsciously adv.,无意中, 不知不觉,presume vt.
2、,假定, 假设, 认为,hypothesis n.,假设,confirmed adj.,证实的, 惯常的, 慢性的,especially adv.,特别, 尤其,uniform adj.,统一的, 相同的, 均衡的,straightaway n.,直线跑道,measurement n.,测量法, 度量, 度量单位制,appropriate adj.,适当的,Lesson 6,New Words & Expressions:,不透明物 /不透明的, 不传热的,realization n.,实现,categories n.,种类, 别, 逻范畴,corrosive adj.;n.,腐蚀的, 腐蚀性
3、的/腐蚀物, 腐蚀剂,rigid adj.,刚硬的, 刚性的, 严格的,disadvantage n.,不利, 不利条件, 缺点, 劣势,obvious adj.,明显的, 显而易见的,isolated adj.,隔离的,孤立的, 单独,moistening n.,润湿,pneumatic signal,气动信号,transparent tube,透明管,opaque n.;adj.,Text,In the control of many industrial processes quantity and level are often unconsciously confused with
4、each other. Probably because one presumes that the dimensions of a tank are constant, one considers that the fluid level in that tank are the image of the quantity it contains.1,在过程工业控制中常常容易将数量和液位相互混淆。因为人们常假设储罐的尺寸是一定的，所以觉得其液位可以看作是储罐所储存的数量。,Lesson 6,Text:,Now this hypothesis is not always confirmed e
5、specially when the tank section is not uniform from top to bottom of the tank. We shall therefore draw the readers attention straightaway to the end result of the measurement he wishes to make; the measurement of the level will not always be the one which is most appropriate.,Lesson 6,现在这种假设不一定成立，特别
6、是当储罐从顶部到底部的截面不均匀时。因此我们将注意力直接放到测量的最终结果上；液位的测量方法不一定是最适当的。,Text:,Methods of measuring levels are very varied, both in conception and realization. Nevertheless they can be divided into four categories; direct measurement, measurement by float, measurement of pressure and special measurement processes. I
7、n any one application the choice of a measurement method will depend on many factors - is the tank open or closed? is it pressurised or under vacuum? is the fluid to be measured solid or liquid? Corrosive or non-corrosive? heated or cold? etc. 2,Lesson 6,液位的测量方法在理论和实际操作中都是变化多端的。可以将液位测量方法分为四类：直接测量法、浮
8、子测量法、压力测量法和特殊测量法。在任何应用中液位测量方法的选择取决于很多因素储罐是封闭的还是开放的？是带压的还是真空的？测量的是固体还是液体？有腐蚀性还是没有腐蚀性？热的还是冷的？等等。,Text:,The measuring principle of direct measurement equipment is extremely simple. It consists of introducing into the tank a rigid graduated rule , of taking it out and visually recording the graduation m
9、ark to which the instrument is wet. 3 An experienced operator may obtain a reading which is accurate to 1/10 of a millimeter. The disadvantages of this method are obvious.,Lesson 6,直接测量方法的设备非常简单。它包括一个导入罐内的刚性刻度尺，从罐内取出从而真实地反映出读数，该测量装置是湿的。一个有经验的操作者能获得一个精确到1/10毫米的读数。这种方法的缺点是显而易见的。,Text:,It involves an i
10、solated (and not continuous) reading of the level, it is limited to moistening non-volatile liquids, and most of all it involves only a visual reading therefore, not one which is converted into an electric or pneumatic signal which can be used in a control loop. 4 Advantages: accuracy and very low c
11、ost.,Lesson 6,它是一个单独的位量读数并且不连续，仅限于非挥发性的液体。大多数情况下只能得到一个直接的读数，而不能转化为可用于控制回路的电动信号或气动信号。其优点是精确和成本低。,Text:,Fig6-2 illustrates another direct measurement technique used when it is possible to fit a graduated transparent tube to the side of a tank. 5 This device gives a direct visual indication but cannot
12、be used when the fluid measured is opaque and leaves a permanent deposit on the transparent tube. However, this method has the advantage of being able to be used in pressurised tanks, which is not the case for the first method.,Lesson 6,图6-2给出了另一种直接测量技术，用在可以在储罐的一侧安装带刻度的透明玻璃管的场合。这种测量装置可以给出直观的读数，但是当被测
13、流体不透明及有沉淀物长久附着在透明管上时不适用。而其优点是适用于带压的储罐，第一种方法不适用于此。,Text:,Moreover, it is possible to read some minimum and maximum levels electrically by placing several photo-electric cells along the transparent tube.,Lesson 6,此外，可以通过在透明管边放置几个光电传感器来直接读取最小值和最大值。,Notes to the Text,Lesson 6,Notes to the Text,1.Probabl
14、y because one presumes that the dimensions of a tank are constant, one considers that the fluid level in that tank are the image of the quantity it contains.,Lesson 6,在句中，because one presumes that the dimensions of a tank are constant为原因状语从句，其中one 为从句的主语，presumes 为谓语，that the dimensions of a tank ar
15、e constant是宾语从句，one considers that the fluid level in that tank are the image of the quantity it contains为主句，其中one 是主语，considers为谓语， that the fluid level in that tank are the image of the quantity it contains为宾语从句，it contains是定语从句，修饰the quantity，其中it 代替 tank。,Notes to the Text,2.In any one applicati
16、on the choice of a measurement method will depend on many factors - is the tank open or closed? Is it pressurised or under vacuum? is the fluid to be measured solid or liquid? corrosive or non-corrosive? heated or cold? etc.,Lesson 6,在句中，choice是主语，will depend on是谓语，factors是宾语，is the tank open or closed? Is it pressurised or under vacuum? is the fluid to be measured solid or liquid? corrosive or non-corrosive? heated or cold? 都是factors 的同位语。 Depend是不及物动词，通常与 on, upon 连用，意为依靠, 依赖，相信, 信赖，取决于
