LVIT inductive linear sensor for cylinder position feedback requires no magnet

mr-7_position_sensor2Alliance Sensors Group is pleased to announce the MR Series of Linear Position Sensors for use in measuring the ram position of hydraulic and pneumatic cylinders. The MR Series is designed to be a drop-in form, fit, and function replacement for magnetostrictive sensors but with much more robust construction and a lower cost of ownership, specifically targeting port-mounted applications of industrial, mobile, or subsea hydraulic cylinders and large pneumatic actuators. MR Series sensors are based on a patented contactless inductive sensing technology that employs a solid probe construction style which requires only a simple conductive tubular target or a small diameter deep hole gun drilled in the cylinder rod for operation rather than needing a permanent magnet ring or some other type of special target.

Features of the MR series linear position sensor include:
• No magnet required
• Measurement ranges from 1 to 24 in. (100 to 600 mm)
• Operates to 5000 psi or 10,000 feet (3000 m) depth
• IEC IP-67 aluminum or stainless steel housing
• Contactless; no wear-out
• 85 C operation (105 C option)
• DC voltage or current analog output
• SenSet Field Adjustable Scaling

Because these sensors use a simple coil design rather than “time-of-flight” technology, the MR Series sensors can withstand intense shocks and vibration, and operating temperatures up to 85 C for standard products and 105 C for custom units. Resembling a magnetostrictive sensor with its sensor head and male o-ring port threads, an MR sensor has a shorter stroke-to-probe length ratio and can thread into the same o-ring bosses (either SAE J1926-8 or ISO 6149-1 M18) that accept a magnetostrictive sensor. For those applications where an MR is replacing an existing magnetostrictive sensor, the magnet ring can usually be left in place without affecting the performance of the sensor.

MR Linear Position Sensors are available in full ranges from 1 inches to 24 inches (25 mm to 600 mm) with either an analog DC voltage or current output, a linearity error of less than or equal to ±0.1% of Full Scale Output, and a -3dB frequency response of 300 Hz. Being contactless, MR Series sensors are not subject to wear and show no output signal deterioration over the life of the sensors. The MR Series comes standard with a 4-pin M-12 connector or 5-pin DIN connector, or with a 4-conductor cable, but other connectors and cable options are available.

The IP-67 sealed housing uses no trimmer pots for setting Zero and Full Scale. Instead, the SenSet calibration feature permits the user to match the analog output of the sensor to the motion of the actuator or cylinder on a stand-alone basis rather than the user having to scale the sensor’s basic output in an associated control system.

Alliance Sensor Group also offers a similar product line to the MR Series called the the ME Series that is embeddable in the rear housing of a cylinder, plus a full line of heavy duty LVDTs and electronics for measuring position in power plants, industrial manufacturing, and process control applications.