There are two methods for performing dimensional measurements: direct measurement and indirect measurement. With direct measurements, measuring instruments such as Vernier calipers, micrometers, and
Direct method of measurement. Fundamental method of measurement. Substitution method of measurement. Comparison method of measurement.
The three measures are descriptive, diagnostic, and predictive. Descriptive is the most basic form of measurement.
Measurement begins with a definition of the quantity that is to be measured, and it always involves a comparison with some known quantity of the same kind. If the object or quantity to be measured is not accessible for direct comparison, it is converted or “transduced” into an analogous measurement signal.
Fundamental Method
The Fundamental Method of measurement determines the value of the quantity being measured by using a basic principle or law of physics. The Fundamental Method is most often used to measure fundamental physical quantities such as length, mass, or time.
Direct method of measurement:
This is a simple method of measurement, in which the value of the quantity to be measured is obtained directly without any calculations. For example, measurements by using scales, vernier callipers, micrometers, bevel protector etc. This method is most widely used in production.
The two systems used for specifying units of measure are the English and metric systems.
Modern instruments used to measure distance can be digital or manual. Industries that pertain to construction or architecture may use laser distance meters. They measure distance without physical contact with the object.
The three standard systems of measurements are the International System of Units (SI) units, the British Imperial System, and the US Customary System. Of these, the International System of Units(SI) units are prominently used.
An Overview of the Measurements
There were formerly four basic measurements such as mass (weight), distance or length, area and volume (liquid or grain).
In the direct method of measurement, the quantity to be measured is compared directly with a standard (an agreed unit of measurement), i.e. the value is determined directly on the part being measured.
Level of measurement or scale of measure is a classification that describes the nature of information within the values assigned to variables. Psychologist Stanley Smith Stevens developed the best-known classification with four levels, or scales, of measurement: nominal, ordinal, interval, and ratio.
The earliest weights seem to have been based on the objects being weighed, for example seeds and beans. Ancient measurement of length was based on the human body, for example the length of a foot, the length of a stride, the span of a hand, and the breadth of a thumb.
The metric system is a system of measurement that uses the meter, liter, and gram as base units of length (distance), capacity (volume), and weight (mass) respectively. To measure smaller or larger quantities, we use units derived from the metric units.
1 Radioactive dating – to know age of fossil fuels rocks etc. 2 Atomic clocks – used to note periodic vibrations taking place within two atoms.
What is a Standard Unit of Measurement? The standard unit of measurement is a value that is fixed and cannot be changed. It is needed to have uniformity in measurement. The measurement is measured as feet, inches, and pounds in the United States and meters, centimetres, and kilograms in the metric system.
The need for various systems of measuring values has come from the nature of the property to be measured and the objectivity in quantifying it. This means that the same quantity can be represented by different scales based on several factors.
The metric system is the primary system of measurement used through much of the world and in science.
In ancient times, the body ruled when it came to measuring. The length of a foot, the width of a finger, and the distance of a step were all accepted measurements. Inch: At first an inch was the width of a man's thumb.
Standard Methods of Measurement (SMMs)
These consist of guidance and a set of rules for the basis of measurement, to ensure that the same items are included (or excluded) in each rate, so that costs for that element can be accurately applied.
(1) Primary Measurements: The measurement obtained directly by observation and comparison is called primary measurement, It needs no convertion, e.g., measuring length, time, mass of a bodv etc. (2) Secondary Measurements: These measurements involve one conversion. e.g. measurement of pressure.
A Nominal Scale is a measurement scale, in which numbers serve as “tags” or “labels” only, to identify or classify an object. This measurement normally deals only with non-numeric (quantitative) variables or where numbers have no value. Below is an example of Nominal level of measurement.
Indirect measurement is a method of using proportions to find an unknown length or distance in similar figures. Two common ways to achieve indirect measurement involve (1) using a mirror on the ground and (2) using shadow lengths and find an object's height.
Measurement methods identify how data will be gathered to measure project progress. They are an important component of a project logframe. Measurement methods are divided into two categories: quantitative and qualitative.