Measurement is a scientific process that is used to compare the measurement of an object or phenomenon with another that has an equal physical magnitude.
That is, the measurement types allow calculating the number of times a pattern is contained in a specific quantity.
In this way the pattern works to obtain the unit of measure to be used. This measure must be unalterable, universal (that can be used anywhere in the world) and easy to reproduce.
However, it should be mentioned that sometimes the measurements may be inaccurate due to the instruments used, which may present failures in the measurement process.
It is the one obtained directly from the instrument used in the measurement process and which has the ability to compare the variable to be measured with a specific standard.
For example, some instruments that perform a direct measurement can be:
- The ammeter, to measure the amperage of an electrical circuit;
- The caliper, to measure the length of an object,
- The stroboscope, to measure the frequency of vibration and rotation of an object.
Indirect measurement is one that is obtained from the calculation of the data set collected from one or more different physical quantities, which were previously calculated through direct measurement. Therefore, indirect measurement is not obtained through a particular instrument.
Some examples of indirect measurement would be the following:
- Speed of an object: measurements of time and distance are used for its calculation.
- Value of a resistance: direct measurement instruments are used, such as the ammeter (which measures current), and the voltmeter (which measures voltage), and the data necessary to calculate the value of a resistance are obtained by applying Ohm's law.
A reproducible measure is one that can be repeated and reviewed several times by different researchers and always obtain the same result. In this type of measurement, it is important that non-destructive tests are carried out. For example, when measuring the length of a large object several times, such as a bed, desk, among others.
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