# 25 Types of Measuring Instruments and Their Functions

A measuring instrument is a tool used to measure the unit value of a quantity. The quantities here vary, such as weight, temperature, length, time, and so on. For example, to measure the length of a branch, you can measure it by using a ruler, which means the quantity measured here is the length and the measuring instrument is a ruler.

Measuring instruments that are wrong in their use will result in measurement errors. For this reason, new users of certain measuring instruments need to read the guidelines for using measuring instruments first.

There are various types of measuring instruments that have their respective functions. Some measuring instruments are commonly used by the general public and some other measuring instruments are used by a certain group of people only. In this article, various types of measuring instruments and their functions will be presented along with pictures so that you will know more about measuring instruments that you may use someday.

## 1. Ruler

A ruler is a long measuring instrument that is used to measure the length of an object. Generally, rulers are made of iron, mica or wood. This measuring instrument is commonly used by the community and is even considered a necessity for children at school. There are 10 cm- to 100 cm-length rulers. The most common length for a ruler is 30 cm.

## 2. Roll Meter

The roll meter is an instrument for measuring the length of an object. This tool is similar to a ruler, except that the roll meter has a longer measuring distance of up to 50 meters. This tool is used in the furniture industry to measure wood or planks for furniture. There is also a roll meter measuring up to 100 meters, but the shape is slightly different from the picture above.

## 3. Elbow Ruler

The elbow ruler is a measuring instrument used to measure the length as well as to ensure that the right angle is equal to 90o. In the picture, the elbow ruler can only check the 90o angle, but there is another form of the elbow ruler that has been equipped with an angle-adjusting feature so that it can be rotated to check the angle of the object. This instrument is usually used in the furniture industry.

## 4. Angle Ruler

This instrument is generally used by children at school to measure the angle of an object or to draw angles. Angle arcs are often found during math lessons and are used to solve math problems. Those who are still at school must have had carried or held this instrument.

## 5. Calipers

A caliper is an instrument used to measure the length, thickness, diameter, and depth of an object. It has a measurement accuracy of 0.1 mm. For example, if we want to measure glass with this tool, we will have the following results:

• The utter diameter using the instrument’s part no. 1
• The inner diameter using the instrument’s part no. 2
• The glass wall thickness with the instrument’s part no. 1
• The depth of the glass using the instrument’s part no. 3

## 6. Micrometer

A micrometer is also used to measure the diameter and thickness of an object. However, this tool has a higher accuracy than calipers with an accuracy of 0.01 mm. Therefore a micrometer is used to measure the diameter and thickness of smaller objects, such as coins.

## 7. Scale

The scale is a measuring instrument used to measure the weight or mass of an object. There are various kinds of scales such as sitting scales, body scales, three-arm scales, digital scales, hanging scales, and others. The scale in the image is a type of sitting scale that is generally used to measure the weight of food ingredients and other commercial objects. Scales are also available in various units depending on the type.

## 8. Thermometer

A thermometer is an instrument that can measure temperature. The temperature read in a thermometer is Celsius (oC). There are several types of thermometers. The picture above is an example of the most commonly used type of thermometer in hospitals or in the laboratory. There is also a type of thermometer that may be encountered during the COVID-19 pandemic, namely an infrared thermometer that is used to measure body temperature before entering a crowded place.

## 9. Beaker Glass

Beaker glass is a volume measuring instrument for measuring the volume of a liquid. This tool is generally used in the laboratory and is used to measure the volume of liquid chemicals before being researched. On the beaker glass, there is a scale in the form of a line that shows the volume size. This tool is available in various sizes, usually the unit is ml.

## 10. Stopwatch

A stopwatch is a measuring instrument used to measure time in seconds. This instrument is usually used to determine runner speed, reaction time, heating time, or time to work on something that is under one hour. This instrument is sometimes replaced by a watch, but the accuracy of the stopwatch is higher than that of a watch.

## 11. Barometer

Barometer is used to measure the pressure of a place or room. This tool is placed in a chemistry or biology laboratory which helps determine the pressure when there is a reaction or the planting of bacteria that is affected by pressure.

## 12. Voltmeter

As the name suggests, a voltmeter is used to measure the amount of electric voltage in units of volts. The method of measurement is by connecting the voltmeter in parallel with the object, then the needle will move according to the object’s electrical voltage.

## 13. Ammeter

The ammeter is almost the same as a voltmeter. Its shape is almost the same, too. However, this instrument is used to measure the electric current of an object in amperes. In addition, the method of measuring with an ammeter must be connected in series with the object.

## 14. KWH Meter

This measuring instrument is often found in front of houses and in boarding houses to measure how much power is used per hour. This tool is a benchmark to see how much electricity bills will be paid by residents of the house or boarding house.

## 15. Dial Indicator

A dial indicator is used to measure the flatness of a flat area. It is generally used in the manufacturing industry to measure the flatness of tools, as well as in workshops which are usually used to measure the flatness of the disc brake in a car. This instrument has an accuracy of 0.01 mm.

## 16. Sound Level Meter

A sound level meter is used to measure the noise level of a place. It is generally used in noise-prone areas such as in industry, aviation, shooting training locations, and so on. Noise needs to be measured to ensure that in that place the noise is within normal limits because noise affects ear health.

## 17. Theodolite

A theodolite is a measuring instrument that serves to map the distance from one point to another. This instrument determines the horizontal and vertical angles between the two points. Usually, this instrument is used by civilian workers to build a building.

## 18. Manometer

A manometer is used to measure gas pressure in a gas area such as a pipe or tube. This tool is used in industries that run on gas or industries that produce gas. This tool can also be found and installed by housewives in gas cylinders.

## 19. Densitometer

This instrument is used to measure the amount of light absorbed by an object or the level of darkness of an semitransparent object or in the form of a film. It can be used simply by pressing the reset button and placing the object on the densitometer. Then, the darkness value will appear on the display.

## 20. Waterpass

A waterpass is a measuring instrument used to determine the alignment of objects or the alignment of objects with other objects both horizontally and vertically. Inside the waterpass, there is water which is the basis for the alignment of objects. If the bubble has fallen between the lines and is no longer moving, then the object is aligned. This instrument is used when constructing building foundations or objects that require alignment.

## 21. Hygrometer

Hygrometer is a measuring instrument used to measure the humidity of a room. Usually, this instrument is used in places that pay attention to humidity such as in the food industry, to prevent high humidity which results in the growth of mold on food.

## 22. pH Meter

pH meter is used to measure the pH of a material. pH here is the level of acidity or wetness of a material. It can be used simply by dipping the pH meter electrode (which is shaped like a pen) into the object as shown in the picture.

## 23. Speedometer

A speedometer is a speed measuring instrument on a vehicle which is usually in units of km/hour. This instrument can be found in motorized vehicles. There are two types of speedometers, namely analog and digital types.

## 24. Anemometer

Anemometer is a measuring instrument for the wind speed of a place. The speed measurement is then used by the geophysical meteorological agency or weather forecasting agency to predict the future weather. The bowl-shaped propeller will rotate when it gets windy and then it is converted by the instrument into a speed value.

## 25. Altimeter

The altimeter is used to measure the height above sea level. This tool is used in climbing, flight, parachuting or activities related to height. Currently the altimeter can be combined with a watch so that it is multipurpose for climbers.

So, those are 25 types of measuring instruments that can add more insight to your knowledge. There are still so many measuring instruments that have not been mentioned in this article. Even in the future, it is possible to find new measuring instruments that have never been predicted before.