Mastering the Art of Measuring with a Beam Balance: A Comprehensive Guide

Are you tired of unreliable measuring tools that make your recipes or experiments a hit or miss? Then, it's time to switch to a beam balance. Beam balances are one of the oldest and most accurate measuring tools that can measure weights up to a precision of 0.01 grams. In this guide, we will explore everything you need to know about using a beam balance effectively.

Beam balances are mechanical devices that work on the principle of counterbalancing weights. They have been used for centuries in various fields such as science, medicine, cooking, and jewelry making. Despite the advent of digital scales, beam balances are still preferred by many professionals for their accuracy and durability.

📋 Index of contents

⚖ Concept

The balance of beams or two dishes is an equipment that is very often used in the laboratory to knowing the weight of a body. The determination of the weight is carried out by the balance between his two arms where the reading of this is taken. This scale can be considered a machine simple.

In Figure 1, the balance of saucers can be seen:

Figure 1. Sample from the Balance of beams

How Does a Beam Balance Work?

A beam balance consists of a beam with two pans suspended from each end. The beam is balanced on a central fulcrum, which allows it to tilt freely. When an object is placed on one of the pans, the weight is counterbalanced by the weights on the other pan, which can be adjusted by sliding them along the beam.

When was the balance created?

The creation of the balance was born in the time of the ancient Egyptians (around 5000 BC). The first types of scales consisted of a central bar and plates that hung from the ends by means of ropes

Beginnings of using the balance

The balance consists of a rigid bar which oscillates on a blade that behaves like a fulcrum or pivot, and which has two other pivots that are parallel and equidistant from the center. The charges u objects to be weighed are held on the plates that the scale has.

The best way to use the scale is with a method called "direct weighing”, where the body to be weighed is placed in one of the plates, then other objects of known weight are placed on the other plate so that the bar of the two plates is balanced. The difference between the reading without any weight and reading with the loaded plates will be the difference between the loads according to the scale to be used.

✅ What is it used for?

This scale is simply used to know the weight of a body. To do this, you should only place what is you want to weigh in one of the dishes, then an object of known mass is placed in the other dish, in order to achieve the balance between both dishes. If this is not finally, another object must be placed on the plate in such a way that stabilization is achieved of these, to finally take the weight reading.

Its frequent uses are: in markets (for the sale of food by kg), laboratories (physicochemical tests that require the weight of materials or substances), cooking (to weigh the ingredients of a recipe), among other uses.

🔴 Features of the beam balance

Below are the characteristics of the two-plate balance:

It has two arms

Because it is a lever of the first kind, since it is obtained from the balance between the two arms that it has. This was one of the first scales to be used, therefore it is an old model that is used infrequently.

The results of the measurements do not vary

It is unusual for the results of measurements to change, however, this depends on the intensity of the gravitational field.

The range and accuracy measurement may vary

In this type
of scales it may happen that I changed the range and precision measurement due to that it is for manual use, therefore, it is very likely that the range will vary.

🔶 Types of beam balance

Several types of two-plate scales can be found, such as the following:

Cross balance

Also called classical balance of two saucers, is a scale consisting of two equal plates attached to a point of support. This is a very old type of balance, so at present it is considered obsolete, however, it is not ruled out that it will continue to be used.

In the following figure you can see the cross balance:

Figure 2. Cross balance

Methodology of use

The use of the cross balance is performed by placing the object to measure its weight on one of the plates, then a standard object of known mass is placed on the other plate, where it is verified if both plates have been stable, if not, one or more objects of known mass is placed until it is achieved, where finally the weight reading of the object of interest is taken.

Roberval's Balance

This is a granary scale that is made up of two plates that are in the same position, it has five bars that are joined together by joints, which make it pivot. This type of balance is less accurate, however, it is faster and more convenient to use with respect to the cross balance. In Figure 3, this balance can be seen:

Figure 3. Sample of the Roberval's Balance

Methodology of use

In this type of balance the employment it is the same as in the cross balance. First the object to be weighed is placed in one from their plates, then an object (usually dumbbells) of known mass is placed, where the stabilization of the two arms of the balance is expected. If they do not stabilize, then more weights of known mass have to be placed on the arm until stabilize. Once the two arms are stable, the reading is taken the weight of the object of interest.

🥇How to use the beam balance

Initially it should be checked that the two plates of the balance are balanced, if they are not you have than to place them in such a position for that purpose. The object to be weighed is placed in one of the dishes, where you wait for them to stabilize the dishes. If they are not balanced the dishes, another object of known mass needs to be placed (usually weights) on the other plate to seek to balance them, if this does not happen, it is need to place more weights until they do.

After balancing the plates of the balance, the reading of the weight of the object is taken on the weight. The object is removed from the plate and the weight(s) from the other plate, and left the balance at rest.

⚖Using a Beam Balance

Using a beam balance is a simple process, but it requires precision and attention to detail. Here are the steps to follow:

Place the beam balance on a flat and stable surface.
Make sure the pans are clean and free of any debris.
Adjust the counterweights to zero the balance.
Place the object to be weighed on one pan.
Adjust the counterweights on the other pan until the beam is balanced.
Read the weight on the graduated scale.
Record the weight and remove the object from the pan.

Advantages of Using a Beam Balance

Beam balances have several advantages over other types of weighing scales, such as:

High accuracy and precision
No need for electricity or batteries
Durable and long-lasting
Can handle large and heavy objects

Tips for Maintaining a Beam Balance

To ensure the accuracy and longevity of your beam balance, here are some maintenance tips to follow:

Keep the pans clean and free of any debris
Store the balance in a dry and cool place
Avoid exposing the balance to extreme temperatures or humidity
Use a soft brush to clean the balance, and avoid using water or harsh chemicals
Regularly calibrate the balance using standard weights

📍 Importance of the balance of beams

The two plate balance is a equipment of great relevance since, because it is old, it can still be used to know the weight of a body or object whether for commercial, intellectual, domestic or others. This equipment is also useful, since since it is manual it can be used in any moment, without relying on electric current unlike electronic scales.

In conclusion, the plate balance is an equipment that is used to determine the weight of an object of interest by means of its two plates, which must remain in balance, being a manual use equipment, it can be used at any time without waiting, therefore, it is very useful and important, so it would be worth having one of these.