Drift related to the instruments, Electrical Engineering

Assignment Help:

If the instruments has no drift it is perfectly reproducible. No drift means that with a given input the measured values do not vary with time.

Drift may be classified into three categories:

(1) Zero Drift: If the whole calibration gradually shifts due to slippage permanent set or due to undue warming up of electronic tube circuits, zero characteristics with zero drift are shown in fig(a).

(2) Span Drift or Sensitivity Drift: If there is proportional change in the indication all along the upward scale, the drift is called  span drift or sensitivity drift. The characteristics with span drift are shown.

(3) Zonal Drift: In case the drift occurs only over a portion of span of an instrument, it is called zonal drift. There are many environmental factors which cause drift. They may be stray electric and magnetic fields, thermal EMFs changes in temperature, mechanical vibration, wear and tear and high mechanical stresses developed in some parts of the instruments and systems.

Drift is undesirable quality in industrial instruments because it is rarely apparent and cannot be easily compensated for. Thus it must be carefully example, stray electrostatic and electromagnetic fields can be prevented from affecting the measurements by proper shielding. Effect of mechanical vibrating can be minimized by having proper mountings. Temperature changes during the measurement process should be preferably avoided or otherwise be properly compensated for.

 

 


Related Discussions:- Drift related to the instruments

Calculate voltage and current phasors on a phasor diagram, Calculate Voltag...

Calculate Voltage and Current Phasors on a Phasor Diagram A synchronous motor is operated at rated load and unity power factor. The field current is increased by 20%. Show the

Aims of the tariff policy - electricity policies, Aims of the Tariff Policy...

Aims of the Tariff Policy - electricity policies: The aims of the National Tariff Policy are to: 1. Ensure availability of electricity to consumers at reasonable and compet

Schematic diagram of a system in which the d/a converter, Q. Develop a sche...

Q. Develop a schematic diagram of a system in which the D/A converter of Figure can be employed in a digital voltmeter.

Difference between neg and not instructions, Mention how do the NEG & NO...

Mention how do the NEG & NOT instructions differ in their functionality Here, NOT: The one's complement or logical inversion NEG: The two's complement or arith

Describe abrasive grit size, Describe the effect of following parameters. ...

Describe the effect of following parameters. Abrasive grit size. Amplitude and frequency of vibration.

Explain basic control systems, Q. Explain Basic Control Systems? Electr...

Q. Explain Basic Control Systems? Electric energy is widely used in practice, because of the ease with which the system and device performance can be reliably controlled. One o

Identify the key cultural dimensions, This assessment requires you to refle...

This assessment requires you to reflect on an intercultural communication event that you have experienced between yourself and an Australian. a)  Describe the event without eval

Explain about half duplex transmission, Q. Explain about Half Duplex Transm...

Q. Explain about Half Duplex Transmission? Half Duplex Transmission A half-duplex channel can receive andsend, though not at the same instance. It's like a one-lane bridge w

Number of holes in valence band, Number of holes in valence band: Der...

Number of holes in valence band: Derive the expression for number of holes in valence band and Fermi level in an intrinsic semiconductor. (b) By that percentage does the

Demodulation of ssb signals, Demodulation of SSB signals also requires the ...

Demodulation of SSB signals also requires the use of a phase-coherent reference. Figure shows the general configuration to demodulate the SSBsignal.Asmall carrier component, which

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd