Analytical balance

November 1, 2021

When we talk about the analytical balance, we are talking about the most accurate balance that we can find in a laboratory , capable of measuring below 0.1 milligrams. For this reason, it is an instrument widely used by physicists and chemists, to find the most reliable data on the weight of a material or substance.

The origin of the analytical balance dates back to 1750, it was designed and used for the first time by the chemist Joseph Black , originally from Scotland. At that time it was extremely novel and, due to the precision of its data, since then it has been the most widely used weight measurement instrument, when it comes to low-weight quantities. Today we have updated models based on electronic mechanisms.

This balance is capable of measuring between 200 grams and 0.1 milligrams, although in more modern models, it has the ability to measure up to 0.01 milligrams.

What is the Analytical Balance?

The analytical balance is a laboratory instrument, used mainly in the area of ​​chemistry, which provides the exact measurement of very small masses or liquids . Its main use and the purpose for which it was designed is to measure materials with a weight below the milligram, with absolute accuracy.

This type of balance is very useful for science, being practically an obligation to have it within the inventory of any scientist in the area of ​​chemistry. The reason is that it is very reliable to measure materials in small proportions, essential data in experimentation and testing of solid or liquid substances that will be subjected to mixtures or changes in temperature.

As this instrument is designed to measure very small masses, below the gram, it is of utmost importance to keep the interaction with the environment at zero , since a gentle breeze, radiated heat from direct contact of sunlight, dust, among others, it may affect the accuracy of the instrument.

For this reason, this instrument is equipped with a protector called a box, commonly, that covers the entire structure of the balance, allowing an environment free of variations when weighing the material.

What is the Analytical Balance for?

This instrument is specifically used to measure the weight of materials, from 0.1 milligrams to 200 grams. As technology is in constant development, these balances, as time goes by, are capable of detecting the weight of even less heavy materials, reaching 0.01 milligrams , with the aim of reaching the real data of the weight of any material.

For this reason, the analytical balance is very useful in the field of chemistry, where the accuracy of the components is necessary to obtain the desired result. As well as the portions must be exact to avoid unexpected reactions, which could threaten the laboratory or the integrity of the scientist.

How does the Analytical Balance work?

This instrument consists of an electromagnetic system, a photocell, a plate and an electromagnet, these being its main components.

It works from the photocell that detects the pan and the movements it makes due to changes in weight, when the material is placed on top of it, causing the electromagnet to balance the force exerted by the load on the pan. In this way, the force is measured, which is interpreted and then displayed on the electronic screen.

Whereas in the original design they worked on the basis of counterweights to measure the weight of materials, today’s analytical balances work with electromagnetic systems, to give an accurate result in degrees of weight even less than a milligram.

Uses of the Analytical Balance

This instrument, like some others, has a specific use that is none other than to quantify the weight of materials . Said like this, it could be taken as a weight or scale, but it really is not, since it differs from these by its impressive degree of sensitivity, capable of capturing the change in weight of objects less than 0.01 milligrams without problem and giving weight data accurately.

Its use for objects between 200 grams and 1 gram is simple. It will be enough to just place the material on the plate to be weighed, the data is marked by an electronic screen so the reading is extremely simple.

While when dealing with weights less than 10 milligrams, it is necessary to take measures to start the measurement , since vibrations, no matter how low they are, can affect the calculation, as well as dust among other things. Therefore, on the one hand, it must be located in a suitable place and be kept there in a fixed way and, on the other, it must be calibrated to correctly quantify the measurements below 10 milligrams.

Knowing how an analytical balance works will facilitate its use in the laboratory, guaranteeing the obtaining of reliable and precise results that favor scientific practice.

Types of Analytical Balances

There are different types of analytical balances, depending on their precision. In addition, they are subdivided according to the type of fine precision, as well as another division on spatial precision that, in general, talks about the amounts of weight that you can accurately quantify, but that you do not need to explain.

On the other hand we have the types of analytical balances according to the technology they use, a more interesting point to take to a description.

  • Mechanical analytical balance

These balances work by means of mechanical parts , characterized by having one or two pans, where the material to be weighed is deposited and some counterbalanced weights on the other side of the apparatus.

Although these balances are taken as analytical, they lack the ability to measure light materials, so they are not used in laboratories for small-scale experiments.

These work with small weights that exert a force contrary to the material on the pan, in order to calculate its weight , making the balance stable between the weight exerted by the material and the weight exerted by the small weights.

  • Electronic analytical balance

Of the two types of balances, this is the one most used in laboratories , as its potential does not far exceed the capabilities of reading the weight of materials, offering accurate data on objects or substances of 200 grams. As well as in liquids or solids of less than 0.01 milligrams without any problem or madness in checking the weight, which is why they practically replaced their more classic sisters, mechanical analytical balances.

These consist of an electromagnetic system that, with an electromagnet, balances the force exerted by whatever is on the saucer. Since it measures very low weights, it is necessary to calibrate it to get the exact measurement of what you are weighing.

Although the original idea was based on the use of small weights to measure how much the materials weighed, time went by and new technologies were designed to improve and optimize the instrument, to such an extent that when talking about the analytical balance, it is commonly referred to as the electronic balances, given that these are the ones that best meet the needs within a laboratory.

Characteristics of the Analytical Balance

This scale has very interesting characteristics, which differentiate it from any other weight measuring instrument, such as its design, capacity, location requirements, among others.

Therefore, it is very useful to know its characteristics and thus take into account both its benefits and certain needs that the instrument has, to work properly.

  • Design

It is a characteristic that stands out when observing this instrument, as they are generally equipped with a glass box as a protector against the outside environment that benefits the balance with an airtight environment when weighing the materials.

  • Measurement Capability

We have talked about measuring between 200 grams and 0.01 milligrams, but actually this scale has updated models capable of measuring up to 0.001 milligrams exactly. It is a very precise level of measurement but, when working with chemical materials or strong reaction substances, it is very helpful to be able to handle very small portions.

  • Requirements for good performance

This instrument does not need to be located in a special room, but if you need to be on a weight firm and , since the vibrations alter the measurement results. Keeping covered with the glass box is important, as the accumulation of dust, no matter how small, causes variations in the measurement.

Attention must be paid to the temperature of the material to be measured or of the environment where we are when making the measurement, since heat can generate distortions when weighing. Similarly, if it receives direct sunlight, it can generate enough heat to make the interpretation of the weight of the material inaccurate.

These are the main characteristics that differentiate the analytical balance from the common balance. Among its characteristics we can also note how useful this balance is and all the benefits that are obtained within the laboratory.

Importance of the Analytical Balance

The analytical balance is capable of measuring all those substances or materials whose low weight cannot be measured by common balances, offering data below the milligram, with total accuracy.

It depends on the analytical balance that we can obtain correct figures, which correspond to the weight of the materials. For this reason, it is widely used by chemists, who when conducting experiments or tests, find it necessary to make sure that the proportions and quantities are exact to obtain positive results.

Another point to highlight, which increases its importance in laboratories, is its design. This scale is equipped with a transparent glass box in order to cover it completely so that at the time of making the measurements, this barrier keeps the material to be measured completely free from alterations by the environment and in this way to have an exact weight calculation.

This instrument is, without a doubt, fundamental in the scientific area, focused primarily on the area of ​​chemistry and biology. It provides us with real and reliable data on the weight of any material subjected to the measurement test.

Dr. Loony Davis5
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Born and raised in Brussels in an English family, I have always lived in a multicultural environment. After several work experiences in marketing and communication, I came to Smart Water Magazine, which I describe as the most exciting challenge of my career.
I am a person with great restlessness and curiosity to learn, discover what I do not know, as well as reinvent myself daily, someone who is curious about life and wants to know. I enjoy sharing knowledge.
This is my personal project but I also collaborate in other blogs, it is the case, the most important web on water currently exists in the US, if you are interested you can read my articles here.

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