Magnetic Speed Sensors - Insights

Different rare earth metals and other metals that make up the magnets for the speed sensors, to control size and price and temperature range of operation. Green energy.

1_For power generation in Gas generators the valve of the Gas inlet is controlled depending on the crank shaft's speed measured using the speed sensor which is quite sensitive because an incorrect value might result in fire or explosion! 2_ For NDT testing of large metal pipes sensors with a convergent electro-magnetic beam are required to detect the crack precisely. 3_ Increasing range for application on baggage processing to identify whether the baggage has metallic objects above a threshold... I would name it as 'thresholding sensors.'

Model airplane engine synchronization - using speed sensors and simple logic to synchronize multi-engine scale model applications.

Magnet encapsulated in flow meter rotor exposed to 100 deg C of oil which has to activate hall switch mounted on flowmeter body when distance between magnet & hall sensor is 4 to 5 mm.

Poor electrical installation, poor grounding practices, poor mechanical installations, too far from target, too close to target, too much vibration, too much heat.

Over rating for temperature especially with respect to long term usage.

Hall switch should operate with lowest possible Gauss value (weakest rare earth magnet of 3mm dia operating at 100 deg C where magnet is about to lose its magnetic field strength).

Faraday effect sensor, velocity range 0 - 5 m/s, low cost OEM device, standard instrumentation interface, non-corroding in saltwater, OK at 20 bar, compact, reliable, robust, calibrated.

- completely robust (dust proof, water proof, shock prof etc ) - its wire should not break as much as you stretch it... I learned it at an auto-parts manufacturing plant where the wire used to get broken because of hardening over time. - range should be 1 cm at-least and directly focused in-front of the head, not around the head. - easily installable - pnp/npn type selector switch should be there on the sensor - sensitivity control knob should be there on the sensor - digital output etc

Yes, talk to an application engineer before selecting a gear for pulse generation. Also make sure that the speed range meets the demand.

Follow manufacturer's guidelines for installation and range to target. Use proper grounding techniques to avoid noise and false signals.

Develop thorough requirements specifications - pay particular attention to environmental specs (temperature, shock, exposure to solvents, etc.).