27-06-2012, 02:32 PM
Vibration Measuring Instruments
[attachment=25769]
Generally in vibration measurement scheme, motion (dynamic force) of the vibrating body is
converted into an electrical signal using a vibration transducer or a pickup. A transducer is a
device that transforms changes in mechanical quantities such as displacement, velocity,
acceleration or force into changes in electrical quantities such as voltage or current. Since the
output of a transducer is too small to record directly, a signal conversion instrument is used to
amplify the signal to the required level.
Transducers
Transducer is a device that transforms values of the physical variable into equivalent
electrical signals. Several types of transducers are available. Some of the transducers used in
vibration measurement are discussed in the following sections.
Vibration Pickups
When a transducer is used in conjunction with another device to measure vibrations, it is
called a vibration pickup. The commonly used vibration pickups are known as seismic
instruments. A seismic instrument consists of a mass-spring-damper system mounted on a
vibrating body. The vibratory motion is measured by finding the displacement of the mass
relative to the base on which it is mounted.
[attachment=25769]
Generally in vibration measurement scheme, motion (dynamic force) of the vibrating body is
converted into an electrical signal using a vibration transducer or a pickup. A transducer is a
device that transforms changes in mechanical quantities such as displacement, velocity,
acceleration or force into changes in electrical quantities such as voltage or current. Since the
output of a transducer is too small to record directly, a signal conversion instrument is used to
amplify the signal to the required level.
Transducers
Transducer is a device that transforms values of the physical variable into equivalent
electrical signals. Several types of transducers are available. Some of the transducers used in
vibration measurement are discussed in the following sections.
Vibration Pickups
When a transducer is used in conjunction with another device to measure vibrations, it is
called a vibration pickup. The commonly used vibration pickups are known as seismic
instruments. A seismic instrument consists of a mass-spring-damper system mounted on a
vibrating body. The vibratory motion is measured by finding the displacement of the mass
relative to the base on which it is mounted.