译文：
阀门定位器伴随着控制阀的应用已有几十年的历史了，由于阀门定位器的出现，使控制阀的控制精度、抗干扰能力、响应时间、流量特性等得到了大大地改善，现在几乎所有的控制阀都使用了阀门定位器，它已经成为控制阀不可缺少的搭档，在自控元件中起着越来越重要的角色。本文主要介绍SAMSON 阀门定位器的工作原理和功能，通过列举模拟和数字阀门定位器，使大家能够比较全面地掌握阀门定位器，其目的是为了我们更好地理解和应用阀门定位器。 虽然阀门定位器由最初的气/气阀门定位器、电/气阀门定位器发展到现在的数字阀门定位器、区域总线阀门定位器，但它们的基本原理和主要功能都没有大的改变。 SAMSON的阀门定位器也跟随着控制技术的发展，经历了由气动、电动、数字、发展到现在的区域总线阀门定位器。在世界同类产品中，SAMSON 的阀门定位器以它的结构紧凑、耗气量低、工作可靠、定位器中可选附加功能多等优势得到了大家广泛的好评。 为了便于大家讨论，我们首先复习一下定位器中的基本自控元件。 定位器中基本自控元件介绍——电/气转换器原理 随着仪表技术的发展，气动仪表领域已逐步被电动仪表和计算机控制所占领，现在只有在一些特殊的场合还在使用气动仪表，作为仪表中的阀门附件“定位器”也由原来的气动阀门（P/P）定位器逐步由电/气（E/P）阀门定位器所代替。 那么在电/气阀门定位器中输入的电信号是如何转换成气信号的呢？我们以SAMSON 6111 型电/气转换器为例介绍一下它的工作原理 气动功率放大器（8）在设计时；选用合适的弹簧力（8.2），使当输入信号为0 mA 时保持输出PA 在100mbar ，这样输出的压力通过恒节流孔（8.4）使喷嘴（7）内有一定的背压。 当输入的信号增加时；通电的线圈（2）切割{yj}磁铁（3）的磁力线，产生向上的力→挡板（6）靠近喷嘴（7）使背压（PK）增加→膜片（8.3）↓→打开阀芯（8.5）→输出PA↑。 当输入信号减少时；挡板（6）离开喷嘴（7）→背压（PK）减少→输出压力（PA）作用下膜片（8.3）↑→阀芯（8.5）关死→输出压力通过阀芯（8.5）释放。 当PA 同PK 平衡时输出压力保持不变；这时电信号在线圈（2）中产生的力也同背压（PK）取得平衡。 这样输入的电信号就转换成气信号了。 定位器的组成 1.反馈杆（1） 2.反馈弹簧（6） 3.反馈风箱（7） 4. 气动功率放大器（7下部） 5. 电/气转换器（21） 定位器工作原理 1. 模拟定位器我们还是以SAMSON的4763定位器为例（参考图3）。我们设：调节阀为FC（气开）；定位器为正作用 A）阀位根据输入信号成比例动作 输入信号↑→Pe 点气压↑→反馈风箱中连杆（9）向左动作→压紧弹簧（6），挡板（10.2）靠近喷嘴（10.1）→输出风压↑→阀杆（对于气开阀）↑→压紧弹簧（6）→反馈风箱中连杆（9）向右动作→挡板（10.2）离开喷嘴（10.1）→输出气压（Pst）↓。当反馈弹簧的力与反馈风箱的力平衡时，阀位保持与输入信号对应的位置。 B）定位 当输入信号不变时：由于工艺条件变化导致阀杆↑→压紧执行器弹簧→压紧弹簧（6）→反馈风箱中连杆（9）向右动作→挡板（10.2）离开喷嘴（10.1）→输出气压↓→由执行器向下的弹簧力使阀位回到原来的地方。 由于工艺条件变化导致阀杆↓→放松执行器弹簧→放松弹簧（6）→反馈风箱中连杆（9）向左动作→挡板（10.2）靠近喷嘴（10.1）→输出气压↑→使执行器向上运动使阀位回到原来的地方。 2.数字阀门定位器 数字阀门定位器与模拟阀门定位器的主要区别是：偏差计算、反馈信号处理、输入/输出信号处理等采用了数字集成电路和微处理器进行处理。 定位器的输入模拟信号经A/D转换后至微处理器（2）；阀门的变化信号经过位置感应传感器（5）和A/D转换也同时到达微处理器。微处理器根据输入信号和阀位信号的偏差经过计算和输出控制信号使供气电磁阀3和排气电磁阀4工作，使阀位与输入信号相对应。通信用的HART信号是经过解调器（1）后至微处理器。 3.HART 定位器 HART定位器同模拟定位器的主要区别是： 1）定位器在接收4~20mA 模拟信号的同时，还可接收到在4~20mA 模拟信号上叠加的一个带有HART 传输协议的交流信号。 2）模拟的4~20mA 信号用于控制阀位，定位器可以用模拟信号发生器进行阀位调校。 3）HART 信号主要用于定位器的设定和组态以及阀门的故障诊断（取决于定位器功能）。 4.PROFIBUS 和Fieldbus 定位器 主要特点是： 1）信号的传输是通过PROFIBUS 或Fieldbus 协议的区域总线进行的。 2）定位器不能直接接受4~20mA 的模拟信号。 3）定位器中含有符合相关协议的输入，输出及PID 控制模块。 4）检查和调校定位器；必须用能与定位器进行通讯和含有应用软件的设备进行。 定位器的基本功能 1. 比例动作和定位作用 比例动作：根据输入的信号，使阀门的阀位与输入信号相对应。定位作用：当输入信号固定时，阀位不受工艺条件的变化而变化。 2. 功率放大 针对气动输入信号而言，定位器可将输入的气信号；通过定位器中的气动功率放大器进行放大，使微小的信号就可以控制阀门动作。 3. 提高阀门的控制精度 由于定位器是根据输入信号与阀门位置的偏差对输出信号进行调整的，一旦输入信号与阀门位置有偏差，定位器将自动调整输出信号以改变阀位，直到阀位与输入信号相对应为止，这样大大提高了阀门的控制精度。 4. 克服摩擦力 由于定位器本身的定位闭环控制，当摩擦力变化时（指阀杆的填料、执行器的密封等部分的摩擦力）；定位器可以根据由摩擦力造成的位置偏差，自动增加或减少输出到执行器的压力，以克服摩擦力对阀门开度造成的影响。 5. 改变作用方式 通过定位器我们可以改变阀门的作用方式。 根据阀门的作用方式我们可按表1来设定定位器的正、反作用。 6.改变阀门特性曲线 阀门的流量特性，除了在阀门制造时通过改变阀芯/座的形状来实现外；我们还可以在定位器中，通过改变反馈量（模拟定位器）和设定参数（数字定位器）来改变阀门的流量特性。SAMSON 定位器中只有数字定位器（3730-2/3，3780，3785，3787）和在角行程应用时的3767模拟定位器；可以通过定位器改变阀门的流量特性。用定位器改变阀门流量特性的实质是：通过改变定位器输入信号和阀位的关系来改变阀门的开度，实现不同的阀门流量特性。我们通过表2看一下通过阀芯形状实现等百分比特性和通过定位器实现等百分比特性有何不同呢？ 从表2我们可以发现：当利用阀芯形状改变调节阀的流量特性时，无论线性和等百分比特性的阀门，它们的开度（行程指示牌）同输入的信号是相对应的。（但实际阀门内部的开度是不同的）而通过定位器实现等百分比特性的阀门开度；相对线性特性而言，其输入信号同阀位的关系有明显的不同，而且它们关系与阀门的结构和类型以及阀门固有的流量特性有关。如果阀门的固有流量特性是线性特性，我们就可以利用定位器很方便地改变它们的特性，反之我们要慎重行事。 7.信号转换/分程控制 我们可以通过定位器实现电/气转换，也可以利用定位器来实现阀门的分程控制。 8. 阀门故障诊断（数字定位器） 在数字定位器中，我们可以利用定位器实现对阀门的故障进行诊断。 9. 整合其它功能（回讯开关，电磁阀，位置变送器等） 利用定位器我们可以将：回讯开关，电磁阀，位置变送器等整合在一起，这样可使阀门的附件之间的连接更加紧凑和可靠，同时也可提高定位器的性能价格比。 定位器分类 SAMSON 阀门定位器有多种类型和功能，我们按主要类型归纳如下： 1.气动阀门定位器 气动阀门定位器有：Type 3760，4765，3766，3761。 2.电/气阀门定位器 模拟定位器有：Type 3730-1，3760，3761，3766，4763；数字定位器有：Type 3730-2，3730-3（HART），3780（HART），3785（PROFIBUS），3787（Fieldbus）。 3.电动阀门定位器 模拟电动阀门定位器：已经整合在3274，5824 等电动执行器中。 结束语 由于定位器在阀门使用中起着举足轻重的作用，如何在实际应用中选用好定位器，对阀门的性能价格比，过程控制的稳定性有很大关系，我们只有充分理解和了解定位器，才能充分发挥它的作用。

“ Electric valve positioner SAMSON control valves to improve performance ”是由提供的国际阀门新闻，译文仅供参考。另外，中国控制阀网还提供相关产品搜索：、、、、等。

原文：
Valve positioner associated with the application of control valves has a history of several decades, due to the emergence of the valve positioner to control the precision control valves, anti-interference ability, response time, flow characteristics have been greatly improved Now almost all of the control valves are used in valve positioners, control valves, it has become an indispensable partner in self-control devices are playing an increasingly important role in. In this paper, the valve positioner SAMSON working principle and function, through the list of analog and digital valve positioner, so that we can more fully grasp the valve positioner, its purpose is to better our understanding and application of valve positioner device. Although the valve positioner from the initial air / gas valve positioners, electric / gas valve positioner to today's Digital valve positioner, the regional bus valve positioner, but their basic principle and main functions are not a big change. SAMSON valve positioner and followed the development of control technology, experienced by the pneumatic, electric, digital, to today's regional bus valve positioner. Similar products in the world, SAMSON valve positioner to its compact structure, gas consumption low, work reliable locator of optional additional features and other advantages over everyone widely praised. To facilitate discussion, we first review the basic look locator controlled components. Locator introduces the basic automation components - electric / gas converter principle With the development of instrument technology, pneumatic Ling Yu 已 gradually by the electric Yibiao and Jisuan Ji Kong Zhi Zhan Ling, Xian Zai only in some special occasions Haizaishiyong pneumatic instruments, valves Fujian Zuo Wei Instrument "Locator" also increased from pneumatic valve (P / P) positioner progressively electricity / gas (E / P) valve replaced locator. Well, electric / pneumatic valve positioner input signal is converted into air signal to it? We SAMSON 6111 type electric / gas converter as an example describe how it works Pneumatic power amplifier (8) in the design; appropriate choice of spring force (8.2), so that when the input signal is 0 mA to maintain the output PA in 100mbar, so the pressure output through the constant orifice (8.4) so that the nozzle (7) There are some back pressure. When the input signal increases; power of the coil (2) Cutting the permanent magnet (3) the magnetic field lines, resulting in upward force → baffle (6) near the nozzle (7) to back-pressure (PK) increased → diaphragm (8.3) ↓ → open spool (8.5) → output PA ↑. When the input signal to reduce the time; baffle (6) leave the nozzle (7) → back pressure (PK) → reduced output pressure (PA) under the action of diaphragm (8.3) ↑ → spool (8.5) shut out the pressure through the valve → core (8.5) release. When the PA output pressure equilibrium with the PK remained unchanged; time signals in the coil (2), also with the back pressure generated force (PK) balance. This input signal is transformed into gas signals. The composition Locator 1. Feedback lever (1) 2. Feedback spring (6) 3. Feedback bellows (7) 4. Pneumatic power amplifier (7 bottom) 5. Electric / gas converter (of 21) Locator works 1. Positioner we were still the 4763 positioner SAMSON example (see Figure 3). We set: control valve for the FC (open air); positive role Locator A) valve position is proportional to the input signal moves Input signal ↑ → Pe point pressure ↑ → feedback bellows connecting rod (9) to the left action → compression spring (6), baffle (10.2) near the nozzle (10.1) → ↑ → Output pressure valve stem (for open air valve) ↑ → compression spring (6) → feedback bellows in the connecting rod (9) to the right action → bezel (10.2) from the nozzle (10.1) → output pressure (Pst) ↓. When the feedback strength and feedback spring bellows of the force balance, the valve position to maintain the position corresponding to the input signal. B) Positioning When the input signal is constant: As the changes in process conditions lead to stem ↑ → → compression actuator spring compression spring (6) → feedback bellows in the connecting rod (9) to the right action → bezel (10.2) from the nozzle (10.1 ) → ↓ → output pneumatic actuator downward by the spring force to valve position back to the original place. As conditions change leading to the actuator stem ↓ → Spring → relax relaxing spring (6) → feedback bellows in the connecting rod (9) to the left action → bezel (10.2) near the nozzle (10.1) → ↑ → output pressure to actuator upward movement of the valve position back to the original place. 2. Digital Valve Positioner Digital valve positioner and analog valve positioner The main difference is: deviation of the feedback signal processing, input / output signal processing using digital integrated circuits and microprocessors for processing. Locator input analog signal by the A / D converted to the microprocessor (2); valve position sensor changes the signal through the sensor (5) and A / D conversion at the same time to reach the microprocessor. Microprocessor to the input signal and valve position signal deviation has been calculated and output control signals to supply solenoid valve 3 and exhaust valve 4, the work of the valve position corresponding to the input signal. Communication with the HART signal is the result demodulator (1) to the microprocessor after. 3.HART Locator HART analog Locator locator with the main difference is: 1) Locator receiving 4 ~ 20mA analog signal, this can also receive the 4 ~ 20mA analog signal with a superimposed HART protocol communication signal. 2) 4 ~ 20mA analog signal used to control the valve position, locator analog signal generator can adjust the valve position. 3) HART signal is mainly used for positioning device settings and configuration, and troubleshooting the valve (depending on the locator function). 4.PROFIBUS and Fieldbus Locator Main features are: 1) The signal transmission is through PROFIBUS Fieldbus protocol or the regional bus. 2) Locator can not directly accept the 4 ~ 20mA analog signal. 3) Locator comply with the relevant agreement contains the input, output, and PID control module. 4) Check and adjust the positioning device; must be able to communicate with the positioning device and a device with application software. The basic functions of locator 1. The proportion of movement and positioning of the role of The proportion of action: According to the input signal to the valve and valve position corresponding to the input signal. Position effect: when the input signal is fixed, valve position changes from changes in process conditions. 2. Power Amplifier For pneumatic input signal, the locator signal can be input gas; through the pneumatic positioner power amplifier amplifies the signal so tiny you can control the valve action. 3. To improve the control precision valve Since locator is based on input signal and valve position deviation adjustment of the output signal, once the input signal and valve position biased, locator will automatically adjust the output signal to change the valve position, valve position and the input signal until the corresponding So far, this has greatly enhanced the precision control valves. 4. To overcome the friction As the locator positioning itself closed-loop control, when the friction force changes (referring to the valve stem packing, sealing and other parts of the actuator friction); positioner can position error caused by the friction to automatically increase or decrease in output to actuator pressure to overcome the friction on the impact of valve opening. 5. Change the mode of action We can change through the valve locator mode of action. According to mode of action of the valve that we can form a set locator is, reaction. 6. To change the valve characteristic curve Valve flow characteristics, in addition to the time of manufacture by changing the spool valve / seat shape to achieve things; we can Locator, by changing the amount of feedback (analog Locator) and setting parameters (figure Locator) to change the valve flow characteristics. SAMSON, only the number locator Locator (3730-2/3, 3780,3785,3787) and rotary application of the 3767 simulation locator; can change the valve positioner flow characteristics. Valve with positioner to change the flow characteristics of the substance is: by changing the positioning input signal and valve position to change the relationship between the valve opening to achieve a different valve flow characteristics. We look through the Table 2 through the disc shape of the realization by the percentage of features and positioning devices such as the percentage of properties to achieve any different? We can see from Table 2: When using spool valve to change the shape of the flow characteristics, the characteristics of both linear and equal percentage valves, opening them (stroke signs) with the input signal is the corresponding. (But within the actual valve opening is different) and the realization by the percentage of Locator features of valve opening; relatively linear characteristics, its input signal with the relationship between valve position significantly different, and their relations The structure and type of valve and valve flow characteristics inherent in the. If the valve is linear characteristics inherent traffic characteristics, we can use the locator to easily change their properties, otherwise we have to be careful. 7. Signal conversion / Split Control We can achieve through locator electricity / gas conversion, you can also use locator to achieve the sub-process control valves. 8. Valve fault diagnosis (Digital Locator) In the digital locator, we can use the locator to realize the fault diagnosis of valve. 9. Integration of other functions (echo switch, solenoid valve, position transmitter, etc.) We can use locator: echo switch, solenoid valve, position transmitter and so together, so make the connection between the valve attachment is more compact and reliable, but also can improve the cost performance locator. Category Locator SAMSON valve positioner has a variety of types and functions, we have summarized the main types according to the following: 1. Pneumatic valve positioner Pneumatic valve positioner with: Type 3760,4765,3766,3761. 2. Electric / Gas Valve Positioner Positioner are: Type 3730-1,3760,3761,3766,4763; digital positioner has: Type 3730-2,3730-3 (HART), 3780 (HART), 3785 (PROFIBUS), 3787 (Fieldbus). 3. Electric valve positioner Simulation of electric valve positioner: already integrated in 3274,5824 and other electrical actuators. Conclusion As used in valve positioners play an important role, how to use in practical applications a good locator, the cost performance of the valve, process control, much to the stability, we can only fully appreciate and understand Locator can fully play its role.