How to Measure the Speed of Centrifugal Pump

How to measure the Centrifugal pump speed, how to measure the pump speed
The speed measurement can be used to determine the rotational speed of the object. A different method can be used to measure the pump speed.
     So how to measure the Centrifugal pump speed?
     1, magnetic induction speed sensor. The magnetic field lines through the sensor coil change, during sensing
     The periodic voltage is generated in the coil. The voltage process is counted. Measured the speed of the pump.
     2, manual vortex tachometer with the end of the shaft or motor shaft at the end of the tachometer.
     3, the electronic counter (in the high precision when used). The pulse signal proportional to the pump speed can be transmitted from the pump shaft of the centrifugal pump to the counter without contact (flash method or magnetic method).
     4, slip meter (slip coil or magnetic needle). Install at a distance from the motor at a certain distance.