FDE型射频导纳高煤位装置
FDE model of radio- frequency transadmitted high coal level equipment
一、概述
FDE-1型射频导纳物位计采用日本富士仪表公司同类产品的先进技术和制造工艺而设计生产的物位测量仪表。该仪表是用于检测料仓、料槽或其它容器中带粘附性的液体、固体颗粒、粉尘、其它混合浆料等料位的位式控制仪表。亦可用于两种不同液体之间界面测量，如油水界面测量。
FDE-1型射频导纳物位计具有校准简单快捷、产品性能稳定、各种型号通用性强、安装方便、外形美观等优点。可广泛用于石油、化工、冶金、电力、医药、食品、造纸、建材等工业领域。且控制器可与PLC可编程控制器或DCS集散控制系统配套使用，实现工艺流程的自动检测和自动控制。
1.     overview
FDE-1 model of radio-frequency transadmitted material level meter is a kind of material level measuring instrument,which adopts advanced and fabricated technology of the same products of Japan Fuji Instrument Company and is designed and producted. These instruments are stepping control meters used to dectect the level of liquid, rigid granules and other mixed sizing agent which are inclined to adhere to the storage hopper, slot and other containers .they are also used to measure the interface between two different kind of liquid, such as measurement of interfiace between oil and water.
RF series of radio frequency transadmitted level meter have excerllent features such as simple and quick calibration, stable performance, easy combination on all the types, easy installation and attractive appearance  est. . it is widely used in Petroleum, chemical , electrical, pharmaceutical, food, papermaking, est. industrial field.
二、结构及工作原理
2.mechanism and principle
1). FDE-1型射频导纳物位计是利用高频技术，由电子线路产生一个小功率射频信号于探头上，探头作为敏感元件，将来自物位介电常数引起的信号变化反馈给电子线路；由于这些变化包括电容量和电导量的变化，因而电子线中处理的是电抗（容抗和阻抗）的综合变化的信号；
1).FDE-1 model of radio frequency transadmitted material level meter  take advantage of high frequency technique.  Electric circuit generates A miniwatt radio frequency signal directing on probe, a sensitive element, which feedback the signal variation generated from medium parameter for material level to electric circuit. Since the variation include the change of electric capacity and conductive capacity, what is processed in the electric circuit is conprehansive signal variation of reactance(condenser components and impedance) ;
2).电抗的变化又引起了极棒上高频信号的相位发生变化。因此极棒和的高频信号与电子线路中的基准信号的相位差也随之发生变化，该变化经处理后，驱动输出电路发出报警信号，从而达到检测料仓有无料位。
2) variation of reactance cause the corresponding variation of high frequency signal on electrode bar. So that the phase difference between the high frequency on the electrode bar and the reference signal in the circuit varies accordingly.  After the variation processed, drive outgoing circuit generate alarm signal, so that material level is detected.
3). FDE-1型射频导纳物位计采用三端Cote – Shield 技术，排除探测极棒上粘附物位对控制作用的影响。电子线路中产生的高频信号，一路直接送往探测极棒，另一路经过一个电压跟随器送往防粘附保护套上。其大小相位都是与加在探测极棒上的信号相同。当有物位粘附在探头上时，由于保护套与仓壁之间构成一个电容，所以加在保护套上的高频信号就会使该电容趋向饱和，以致探头上的高频信号就无法通过粘附层流入容器壁，当容器内大量物位接触探头时，探头上的电流绕过饱和区流向容器壁，从而产生有料位存在信号。
3). FDE-1 model of radio frequency transadmitted material level meter adopt three terminal Cote-shield technique to exclude the influence on control function from material adhered on the detective bar.  The high frequency generated from the electric circuit is sent to detective bar directly in one way, and sent to anti-adhesive cover through a voltage follower on the other way. Both max. and min. phase are same as the signal on detective bar. When material is adhered on the probe,  since protective cover and container wall make up a capacitance, high frequency signal on the protective cover will make the capacitance tend to saturation, so that the high frequency signal on the probe can not go through layer with adhesine material to container wall. When plenty of material contact  the probe in the container, the electric current on  the probe will round the saturation area to the container wall, thus the signal indicating the existance of material is generated.
三、主要技术参数
工作电源：24VDC；220VAC
相对湿度：≤85%
输出信号：两组常开、常闭触点
触点容量：AC220V，5A; DC24V，3A
环境温度范围：-40℃~+60℃
介质温度：-180℃~+500℃
延迟时间：0.2S（0.2~30S可调）
防护等级：IP65
探头材质：316不锈钢、四氟乙烯、高温塑料、陶瓷
防爆等级：ExdIIBT4
连接方式：3/4″管螺纹；3/4″NPT螺纹；1 – 1/ 4″NPT螺纹；法兰（可选）
安装方式：顶装、侧装
3.main technical parameter
power supply: 24VDC ; 220VAC
relative humidity(RH): <=85%
outcoming signal: double frequently opening or closing contact
contact carrying rating: AC220V,5A;  DC24V,3A
Ambient temperature range: -40C --+60C
Medium temperature: -180C --+ 500C
Delay period: 0.2s (0.2-30s adjustable)
Protection grade: IP65
Probe material: 316 stainless steel , perfluoroethylene, hot plastics, ceramics
Explosion grade: ExdIIBT4
Connection way: 3/4” pipe thread,  3/4” NPT  screwthread, 1-1/4 NPT screwthread; flange (optional) .
Way of installation:  top installing , side installing