Table of Contents
What is damping in measuring instruments?
Damping is the amount of time required to reach 63.2 percent of the transmitter’s final value after a step change has been applied to the input, in addition to the update time. The damping of transmitters can be adjusted from 1 to 32 seconds.
Why is damping necessary?
Damping is a way to limit vibrations and is essential for protecting the system in which it operates. This is what happens with door or drawer springs, where damping prevents blows when opened/closed, preserving them and protecting the system.
Which type of damping is preferred in analog meters?
Eddy current damping ‘or’ Electromagnetic Damping: It is the most efficient type of damping.
Which type of instrument is used with their function damping?
Therefore, this type of damping is used in moving iron and dynamometer type of instruments where the operating magnetic field is weak and is likely to be get distorted with the introduction of a permanent magnet.
What is the purpose of damping torque in Pmmc meter?
Damping – The damping torque is used for keeping the movement of the coil in rest. This damping torque is induced because of the movement of the aluminium core which is moving between the poles of the permanent magnet.
What are the different types of damping system for analog instruments?
There are four ways of producing damping torque, and they are:
- Air friction damping.
- Fluid friction damping.
- Eddy current damping.
- Electromagnetic damping.
What is the role of damping factor in the vibrations?
Damping is responsible for the eventual decay of free vibrations and provides an explanation for the fact that the response of a vibratory system excited at resonance does not grow without limit.
Why does damping occur in oscillating system?
Damping occurs when a force is exerted on the oscillating object that causes the amplitude of its oscillations to get smaller and smaller over time. If a driving force is applied at the same frequency as the natural frequency, then the amplitude of the oscillations can increase dramatically.
Which damping is more efficient?
Eddy current damping: When a conductor moves in a magnetic field an emf is induced in it and if a closed path is provided, a current (known as eddy current) flows….4.6.
| Type of damping | Instruments used |
|---|---|
| Eddy current damping | PMMC and induction type (which are used permanent magnet) |
| Electromagnet damping | Flux meter |
What is a damping force?
damping, in physics, restraining of vibratory motion, such as mechanical oscillations, noise, and alternating electric currents, by dissipation of energy. Unless a child keeps pumping a swing, its motion dies down because of damping.
How is damping provided in majority of instruments?
In the majority of instruments, damping is provided by eddy current damping. Eddy current damping: This torque is proportional to the strength of the magnetic field and the current produced.
Why is damping torque necessary for an analog type instrument?
In a measuring instrument, the damping torque is necessary to bring the moving system to rest to indicate steady reflection in a reasonable short time. Similar to friction, it only acts when a system is in motion, and is not present if the system is at rest.
What does it mean when an instrument has too much damping?
If the damping torque is more than what is required for critical damping, the instrument is said to be overdamped. In an overdamped instrument, the moving system moves slowly to its final steady position in a lethargic fashion.
What is damping in process transmitters and learning instrumentation?
Most transmitters incorporates a sensor which measures the input variable and gives out an output of which 4 – 20m A is common. Of critical importance in the performance of a transmitter is a concept called damping. As the input variable changes, the transmitter output must update and change accordingly.
What is the damping time on a radio?
Transmitter damping is adjustable from 1 to 32 seconds. Damping reduces the effects of electrical noise and any other insignificant transient noise that may influence the transmitter output signal.
When is damping not needed in a process?
In the absence of electrical or transient noise, damping may not be required in processes that are slow and have inherent lag time e.g temperature control loops. Damping should be minimized in fast changing process conditions.