| 品牌 | FISHER | 型号 | 4210,4211，4212，4215,4220，4221，4222 |
| 类型 | 变送器 | 测量范围 | 仪表阀 |
| 输出信号 | 4-20（mA） | 电源 | 无 |
| 材质 | 多种材质 |
一.简介
the 4200 series electronic position transmitters combinefisher’sfield-proven electronic and mechanicalexpertise in a versatile,accurate instrument thatsenses the position of a device, and sendsa standard(4 to 20 milliampere)output signal to an indicatingdevice.the instrument is available as a transmitter withintegralhigh and low electronic travel limit alarms, as atransmitter only,or with electronic travel limit alarmsonly.
the instrument can sense the position of rotary or slidingstemvalves, vents, dampers or other devices.when the instrument ismounted, a potentiometershaft is mechanically connected to thedevice to sensemechanical motion. for a standard instrument,asingle potentiometer is provided for position input, or anoptional dual element potentiometer is available to allowindependent electrical operation of the transmitter and alarmcircuits.
the instrument has standard, or long stroke (see figure 5),capabilities for sliding stem actuator applications.
for long stroke applications, a multiturn potentiometer attached toa cable/pulley assembly is used to sense linear motion of theactuator stem or other devices. the instrument with standardcapabilities can also be used on quarter-turn actuators.
for instruments equipped with electronic travel limit alarms,individual electronic high and low alarm circuits
drive separate high and low alarm spdt relays. the user adjusts thetrip point and deadband of the high and low alarms to the desiredtravel limits. when the sense potentiometer voltage is higher thanthe high trip point, the electronic high alarm circuit de-energizesthe high alarm relay. when the sense potentiometer voltage is lowerthan the low trip point, the low alarm circuit de-energizes the lowalarm relay. the low trip point may be offset from the high trippoint by as little as 5% of the remaining span. in the event of apower loss to the alarm circuits, both alarms are tripped (bothrelays are de-energized). this indicates a availableconfigurations.
二.具体型号及分类
应用于角行程的有：4210，4211，4212，4215
应用于直行程的：4220，4221，4222