ASTM: (Formerly known as The American Society for Testing and Materials) An international standards developing organization that develops and publishes voluntary technical standards for a wide range of materials, products, systems, and services.
气压: The force exerted per unit area by the weight of the atmosphere.
英国热门单位（BTU）: The amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. Melting a pound of ice at 32°F requires 143 BTU.
BSPT: British Standard Pipe Thread.
Capacitance: A measure of the amount of electric charge stored (or separated) for a given electric potential. The most common form of charge storage device is a two-plate capacitor.
Cavitation：随着压力开始增加，控制阀内流动液体坍塌的蒸汽气泡的过程。
闭环: A control system that provides feedback to a controller on the state of the process variable.
冷端: The end of thermocouple that is kept at a constant temperature in order to provide a reference point.
联系人：用于机械制造或打破电路的元素。
Critical Pressure: The ratio of upstream to downstream pressure where the gas velocity out of the valve is sonic and further decreases in downstream pressure no longer increase the flow.
CV或阀门流量系数：60°F的水每分钟每分钟每分钟的加仑数量，将通过阀门，压降1psi。
Deadband：交换机致动和脱模之间的测量值。
密度：每单位体积的给定物质的质量。
Derivative Control: A method of changing the output of a controller in proportion to the rate of change of the process variable.
露天: The temperature to which air must be cooled for the air to be saturated with water.
介电：电容器的导体之间的绝缘材料。
介电常数：材料绝缘能力与真空绝缘能力的比率。
din: Deutsches Institut für Normung e.V., The German national organization for standardization and is that country’s ISO member body. DIN and mini-DIN connectors, as well as DIN rails are several examples of older DIN standards that are today used around the world.
Direct Current (DC)：具有恒定极性的电流。
双极双掷（DPDT）开关: Two separate switches that operate simultaneously, each with a normally open and a normally closed contact and a common connection.
漂移: A gradual change in an element over time when the process conditions are constant.
干灯泡温度: The ambient air temperature measured by a thermometer that is freely exposed to the air but shielded from other heating or cooling effects.
Emissivity: The ratio of energy radiated by the material to energy radiated by a black body at the same temperature. It is a measure of a material’s ability to absorb and radiate energy.
Form-C Contact：具有常开和常闭触点的接触。
模糊逻辑：一种使用基于模拟输入的模糊集的数学或计算推理的系统。
Gage Pressure (psig): The measure of force per area exerted by a fluid using atmospheric pressure as the zero reference.
Gain：输出变化与进程输入变化的比率。
热门交界处: The joined end of the thermocouple that is exposed to the process where the temperature measurement is desired.
湿度: The amount of water vapor in a given volume of air or gas.
Laminar Flow: Smooth fluid flow that has a parabolic flow profile with no mixing between streamlines.
线性: Ability of a measuring instrument to provide an indication having a linear relationship with a defined quantity other than an influence quantity. [IEC 60050-300]
注意: The method of expression of lack of linearity is different for different kinds of instruments and is established in each particular instance.
Long-Term Span Drift: The amount of change of a measured reading with 90% of full scale range pressure applied and constant ambient conditions over a given period of time which is typically quoted as an annual figure. [IEC 61298-2]
Long-Term Zero Drift：测量读数的变化量，零压力施加零压力和恒定的环境条件，在给定的时间段内通常引用为年度数字。
Low Pressure Steam: As defined by ASME, steam under 15 psi pressure.
手动重置：在从警报状态下将返回其正常状态之前必须具有人类输入的控制。
Maximum Surge Pressure：开关外壳的安全压力，但这可能通过连续或重复应用损坏机制。
3-A: 3-A Sanitary Standards Inc., A non-profit association representing equipment manufacturers, processors, regulatory sanitarians, and other public health professionals that creates standards and accepted practices for dairy and food processing equipment and systems.
Total Pressure：速度和静压之和。
传感器：任何从物理测量产生电信号的设备。
发射机: A device that translates the low-level output of a sensor or transducer to a higher level signal suitable for transmission to a site where it can be further processed.
Turbulent Flow: Fluid flow in which the flow profile is a flattened parabola, the streamlines are not present, and the fluid is freely mixing.
调低比: The ratio of the maximum to minimum measurable value that can still produce full-scale output.
Velocity Pressure (Dynamic Pressure): The pressure exerted by the velocity of a fluid. Can be measured by the difference between total and static pressure.
