3120-300 Product Description Product Overview 3120-300 is a part of the Bently series of eddy current preamplifiers. It is an important signal conversion and conditioning unit in the state monitoring system for rotating machinery. This device is specifically designed to be used with eddy current sensors and adopts a compact industrial circuit architecture. It operates stably and has strong anti-interference capabilities. It can adapt to complex industrial site conditions and supports 7×24-hour continuous operation. The preamplifier mainly provides a stable power supply for the front-end sensors, receives the weak sensing signals transmitted by the sensors, completes amplification, shaping, and linearization processing, converts the original signals into standard industrial signals, and then transmits them to the subsequent monitoring module. It is the core transfer device connecting the sensing probe and the monitoring host, directly determining the signal quality and measurement accuracy of the entire acquisition loop. It is widely used in various large-scale rotating machinery online monitoring scenarios. Basic Information This product follows the industrial field instrument design specifications. Its overall structure is compact and the shell is made of high-strength flame-retardant material. It has the characteristics of dust-proof, oil-proof, and resistance to slight mechanical impact. It can be directly installed in the local cabinet of equipment, near the bearing seat, on the site wiring box, etc. The electrical interface of the equipment is standardized. The input end can directly connect to the same series eddy current sensors and extension cables, and the output end is compatible with various vibration and displacement monitoring modules. The wiring method is simple and clear. The internal circuit has been precisely calibrated at the factory, with good parameter consistency. After installation, it can be put into use without complex debugging. The product is compatible with conventional industrial power supply conditions. The circuit protection design is complete, capable of withstanding minor fluctuations in the power grid and on-site electromagnetic interference. It is compatible with all series of sensors and monitoring modules of Benitez, and is convenient for later maintenance and spare parts replacement. Functions and Positioning This equipment mainly undertakes three functions: power supply, signal conditioning, and signal transmission. Firstly, it provides a constant working voltage for the front-end eddy current sensors to ensure their stable oscillation and normal data collection; secondly, it receives the weak alternating signals output by the sensors, amplifies, filters, and performs linear compensation processing on the signals, correcting the non-linear deviation caused by eddy current measurement characteristics, and ensuring that the output signal maintains a precise linear relationship with the measured displacement and vibration quantity; finally, it transmits the processed standard signals over a long distance to the subsequent monitoring unit. The equipment has basic circuit monitoring capabilities and can cooperate with the system to identify circuit faults such as sensor breakage and line short circuit. As the core of the sensing link, it is mainly used for signal conversion, level matching, and line driving scenarios in the eddy current measurement circuit, establishing a reliable electrical link between the front-end acquisition and the subsequent monitoring, ensuring the accuracy and continuity of parameter measurement such as vibration and axial displacement. Core Performance Parameters The equipment's output power supply voltage is stable, with a low ripple coefficient, providing a pure working power supply for the sensors. The signal conditioning has a wide linear range, with the full-scale linear error controlled within the industry standard range, high measurement repeatability, and no obvious zero drift or range shift during long-term operation. The internal circuit integrates multiple filtering and electromagnetic shielding circuits, which can effectively suppress electromagnetic interference generated by frequency converters, high-power motors, and high-voltage lines, avoiding signal noise, jumps, and distortion. The signal response is fast, the transmission delay is extremely low, and it can synchronously restore the dynamic running state of the rotating shaft. The circuit conversion efficiency is high, the working heat generation is low, the heat dissipation performance is good, and the performance remains stable in high and low temperature environments. The electrical insulation strength meets the standards, the input and output circuits are isolated reliably, and it has basic electrical protection functions such as overcurrent and short circuit, which can protect itself and the front-end equipment in case of abnormal lines. The working temperature and humidity range covers the industrial local equipment area, junction boxes, cabinets, etc., with strong environmental tolerance, and the overall mechanical and electrical service life meets the requirements of industrial long-term operation. General Compatible Accessories Installation and fixation can be combined with standard installation brackets, fixing screws, shock-absorbing pads, etc., to achieve stable installation of the equipment and weaken the impact of mechanical vibrations in the site. Wiring construction can use shielded signal cables, wiring terminals, cable clips, waterproof connectors, etc., to standardize the wiring layout, improve the protection level of the lines and the stability of signal transmission. The system requires matching with the same specification eddy current sensors and extension cables to form the front-end acquisition unit, and the output end can be connected to vibration monitoring modules, axial displacement monitoring modules, TSI system racks, etc., as the subsequent equipment. The easy-to-damage accessories such as wiring terminals and seals of the product are of standard specifications, and spare parts procurement and replacement are convenient. Daily inspection, circuit testing, and fault troubleshooting can be completed using conventional industrial electrical tools. Applicable Equipment Fields The product is widely used in power generation, petrochemicals, coal chemical industry, metallurgy, oil and gas extraction, heavy equipment manufacturing, etc., in industrial fields. It is mainly used in the condition monitoring systems of large and medium-sized rotating mechanical equipment such as steam turbine generators, gas turbines, centrifugal compressors, flue gas turbines, large draft fans, high-pressure pump sets, and heavy-duty gearboxes. It is usually installed nearby in the wiring boxes of the equipment's bearing areas or in the local control cabinets, cooperating with eddy current sensors to complete the signal conditioning of parameters such as shaft vibration, axial displacement, and rotational speed, providing reliable signal support for the monitoring of the entire unit, fault early warning, and safety interlock systems, ensuring the safe and stable operation of the core power equipment.