Instruments used to measure angular velocity

Angular velocity is measured using devices called tachometers.Tachometers are instruments that measure angular speed by registering anyone of the following

Number of rotations during the contact period (or)

• Number of rotations per minute (rpm)
• Tachometers are classified as follows:

Mechanical Tachometers

1. Revolution counter and timer
2. Tachoscope
3. Hand speed indicator
4. Slipping clutch tachometer
5. Centrifugal force tachometer
6. Vibration reed tachometer

Electrical tachometers

• Drag cup tachometer
• Commutated capacitor tachometer
• Tachogenerators
• DC – Tachogeneraor
• AC – Tachogeneraor

Contact Less Electrical Tachometers

1. Inductive pick up tachometer
2. Stroboscope tachometer
3. Photoelectric tachometer
4. Capacitor tachometer