The SHINKAWA MP-2T is a passive electromagnetic sensor, commonly referred to as a magnetic pickup (MPU). Its primary function is to monitor the rotational speed of machinery without making physical contact. This is achieved by mounting the sensor in close proximity to a rotating ferrous target, such as a gear tooth or a slotted shaft. As each tooth passes the tip of the MP-2T, it causes a change in the magnetic flux within the sensor, which in turn induces a voltage pulse in the internal coil. The frequency of these pulses is directly proportional to the RPM of the rotating shaft.
Because the MP-2T is a passive device, it does not require an external power supply to generate its signal. The energy for the output pulse is derived entirely from the movement of the target through the magnetic field. This simplicity makes the MP-2T inherently reliable and suitable for use in extreme environments where electrical failure of active components might be a concern.
The internal construction of the SHINKAWA MP-2T consists of a permanent magnet, a pole piece, and a fine wire coil, all housed within a rugged stainless steel body. The sensor is hermetically sealed to protect the delicate internal components from industrial lubricants, moisture, and dust. The tip of the sensor is designed to provide a focused magnetic field, which allows for precise detection even at high speeds or with small target geometries.
The output of the MP-2T is a quasi-sine wave signal. As the speed increases, both the frequency and the amplitude of the voltage pulses increase. This signal is typically sent to a tachometer, a governor, or a vibration monitoring system (such as the Shinkawa VM series). These systems process the raw frequency into a digital RPM value. The high sensitivity of the MP-2T ensures that it can provide a usable signal even at low rotational speeds, provided the air gap between the sensor and the target is correctly maintained.

Shinkawa specializes in monitoring equipment for high-performance rotating machinery, such as steam turbines, gas turbines, and large compressors. Consequently, the MP-2T is built to withstand extreme mechanical stress. It features high resistance to vibration and shock, ensuring that the signal remains stable even when the machine is operating at its limits. The stainless steel housing is resistant to corrosion, making it suitable for marine applications and offshore platforms.
The temperature rating of the MP-2T is another critical technical advantage. It can operate in environments where temperatures reach levels that would destroy standard industrial sensors. This high-temperature capability is essential for sensors mounted near turbine bearings or inside engine housings. The cable connection is often reinforced or features specialized insulation to ensure that the electrical signal is not degraded by the heat or by electromagnetic interference from nearby power equipment.
Proper installation is the key to the performance of the SHINKAWA MP-2T. The sensor is usually threaded into a mounting bracket, allowing for fine adjustment of the air gap. If the air gap is too large, the signal amplitude will be too low for the monitoring system to detect; if it is too small, there is a risk of mechanical contact with the rotating target. Shinkawa provides precise specifications for the air gap to ensure optimal signal-to-noise ratios.
Maintenance of the MP-2T is minimal due to its lack of moving parts and passive nature. However, periodic checks of the sensor tip for the accumulation of metallic debris (which can distort the magnetic field) and inspections of the cable integrity are recommended. Because of its critical role in overspeed protection systems, the MP-2T is often used in redundant pairs or trios, ensuring that the machinery can be safely shut down if a single sensor fails or if an actual overspeed event is detected.



