To understand the concept of errors in measurement, we must know the two terms that define error and these two terms are written below:
True Value:
It is not possible to determine the exact value of a quantity by experimental means. The true value can be defined as the average value of an infinite number of measured values when the average deviation due to a varying contributing factor will approach zero.
Measured Value:
It very well may be characterized as an estimated worth of the genuine worth. This not entirely settled by taking various estimated readings during an examination, making suitable presumptions on states of being.
We are currently in a situation to characterize static mistake. Static blunder is characterized as the contrast between the deliberate worth and the genuine worth of the amount.
Numerically we can compose the mistake articulation, dA = Am – where, dA is the static blunder Am is the deliberate worth and At is the genuine worth.
It ought to be noticed that the outright worth of the mistake not entirely set in stone because of the way that the genuine worth of the amount can’t still up in the air.
We should consider a couple of terms connected with blunders.
Limiting Errors or Guarantee Errors:
If we study this type of error by considering an example, the concept of warranty errors can be clarified. Suppose there is a manufacturer who manufactures an emitter, now he must promise or declare that the emitter he is selling does not exceed the specified limit. This margin of error is known as bounding errors or margin of error.
Types of Errors:
Essentially there are three sorts of blunders on the premise; they might emerge from the source.
Gross Errors:
This category of errors includes all human errors during reading, recording and reading. Errors in calculating errors also fall into the same category. For example, taking a reading from the instrument’s meter, he may read 21 as 31. All these types of defects fall under this category. Common errors can be avoided by using two appropriate methods and they are listed below:
- A legitimate consideration ought to be taken in perusing, recording the information. Likewise computation of mistake ought to be done precisely.
- 2. By expanding the quantity of experimenters we can diminish the gross blunders. On the off chance that every experimenter takes different perusing at various places, by taking normal of additional readings we can diminish the gross mistakes.
Systematic Errors:
To understand these types of errors, let us classify systematic errors.
Instrumental Errors:
These errors may be due to improper construction, calibration of measuring instruments. This type of error can be due to friction or due to hysteresis. These types of errors include loading effect and misuse of equipment. Improper use of the instrument results in failure of the zero adjustment of the instrument. Various correction factors should be applied to reduce the gross errors in the measurements and in extreme cases the instrument should be carefully re calibrated.
Environmental Errors:
This type of error is caused by external conditions of the device. The external condition includes temperature, pressure, humidity or may include an external magnetic field. Following steps should be taken to reduce environmental errors:
- Try to keep the temperature and humidity of the laboratory constant by making some arrangements.
- Ensure that there should be no external magnetic or electrostatic fields around the device.
Observational Errors:
As the name suggests, these types of errors are caused by incorrect observations. Inaccurate observations may occur due to PARALLAX. Highly accurate meters are required to minimize PARALLAX error, provided with mirror scales.
Random Errors:
After calculating all the systematic errors, it turns out that there is still some error in the measurement. These errors are known as random errors. Some of the reasons why these disorders appear are known, but still others are unknown. So we cannot completely eliminate these types of errors.
