Speed Pickup Sensors

Speed Sensors Magnetic Pickup

For sensing rotational Speed

To control the rotational speed of a prime mover, speed controls compare actual speed to desired, or set, speed. When a magnetic material (usually a gear tooth driven by shaft) passes through the magnetic field at the end of the magnetic pickup, a voltage is developed. The frequency of this voltage is measured by the speed control.

Installation

Magnetic speed pickup is usually mounted radially to the gear, either through the housing or on a rigid bracket. Sensor must be mounted off the face of the gear, be sure to check For gear end play in addition to gear run out. Petro davvar energy have installation manuals For each sensor.

Types of Magnetic pickups

Petro Davvar Energy is manufacturing Magnetic pickups in different lengths and mounting thread sizes according to API 670. See some of Our magnetic pickups require a connector which you can see on catalog.

Setting the Gap

The gap between the end of the sensor and the gear tooth is set at 0.25 to 1.4 mm (0.010 to 0.055 inch) at the closest point. The sensor will be damaged if it touches the moving gear. A properly installed sensor will provide as much as 50 Vac (rms); most turbine controls require a minimum of 1.5 Vac at the lowest speed. Voltage decreases as the sensor is moved farther from the gear. If the gap between the pickup and the gear cannot be measured directly, it can be determined by counting the number of turns the pickup is backed away from the gear. One full turn counterclockwise will move the sensor out 0.055 inch (1.4 mm For example For Solar centaur gas turbine).