FBM201d Foxboro FOXBORO Controller, Shanghai Sijian Intelligent Technology Co., Ltd. is engaged in technical development, technical consultation, technical transfer in the fields of intelligent technology, information technology, and automation technology, as well as the sales of electrical equipment, automation equipment, electronic products, communication products, and electromechanical products. Industrial automation products include: PLC, DCS, sensors, frequency converters, encoders, relays, servo drives, soft starters, and touch screens. The brands involved in the products are: Eurotherm, Schneider, Siemens, ABB, SICK, P+F, E+H, Yokogawa, Yamakawa, Mitsubishi, Emerson, Honeywell, FANUC, GE, Eaton Electrical, CT. The local indication function of the FT200 drum level gauge is mainly based on the principles of magnetic coupling and buoyancy to detect liquid level or interface level. Inside a non-magnetic chamber (external float chamber), there is a magnetic float that always remains suspended at the liquid or interface level. The position of the float changes synchronously with the drum level. Outside the float chamber is an indicator, which is a vacuum-sealed glass tube containing a magnetic fly flag or magnetic flap indicator. Through magnetic coupling, it attracts and synchronizes with the float inside the chamber, indicating the corresponding position of the float, i.e., the height of the liquid or interface level, thereby achieving synchronous indication of the liquid or interface level.
FBM201d Foxboro FOXBORO Controller, The remote control function of the drum level gauge primarily utilizes the magnetostrictive principle, where the intersection of two different magnetic fields generates a strain pulse signal to accurately measure position. The measuring element is a waveguide tube, and the components inside the waveguide tube are made of special magnetostrictive material. The measurement process begins with the generation of a current pulse in the sensor's electronic chamber. This current pulse travels through the waveguide tube, creating a circumferential magnetic field outside the tube. When this magnetic field intersects with the magnetic field generated by a movable magnetic ring (which changes position along the waveguide tube), a strain mechanical wave pulse signal is produced inside the waveguide tube due to magnetostriction. This strain mechanical wave pulse signal travels at a fixed speed of sound and is quickly detected by the electronic chamber. Since the transmission time of this strain mechanical wave pulse signal in the waveguide tube is proportional to the distance between the movable magnetic ring and the electronic chamber, measuring the time allows for highly accurate determination of this distance. Because the output signal is a true signal rather than a proportional or amplified one, there is no signal drift or value change, and no periodic recalibration is required.
The high and low liquid level alarm function of the drum level gauge mainly uses the magnetic induction principle. Magnetic switches are installed at the high alarm point and low alarm point on the measuring float chamber to detect the float. When the float reaches the low point, the magnetic field of the magnetic switch detects the magnetic field of the float, generating a fixed, strong mechanical wave pulse signal. The magnetic switch circuit then issues a control command, identifying it as a low liquid level alarm. When the float reaches the high point, the magnetic field of the magnetic switch detects the magnetic field of the float, generating a fixed, strong mechanical wave pulse signal. The magnetic switch circuit then issues a control command, identifying it as a high liquid level alarm.