Laboratory scales are specific equipment for precise measurements of the mass of a body in a laboratory or industry, for segments in which analyzes, formulations and experiments in general require total precision. There are several types of scales that are developed according to international metrological and quality standards and controlled by INMETRO.
So, what criteria should be taken into account for and choosing the best balance for your laboratory or industry?
TYPES OF SCALES
Balances are defined by high levels of accuracy and precision in analytical tests and quantitative analyzes. Used in several applications, they are divided into five subcategories, according to their readability:
- Precision scales (> = 0.001 g)
- Analytical scales (0.0001 g)
- Semi-micro scales (0.00001 g)
- Micro scales (0.000001 g)
- Ultra-micro scales (0.0000001 g)
SOME BASIC CONCEPTS
To fully understand how the types of scales operate, it is necessary to understand the difference between mass and weight.
Mass is a constant unit of the amount of matter an object has. It remains the same, no matter where the measurement is taken. The most common units of mass are the kilogram and the gram.
The force with which any mass is attracted to the center of gravity, varies with the position on the planet’s surface and its distance, being also influenced by factors such as magnetism, speed, buoyancy, temperature effect, static electricity.
Although mass and weight are two different quantities, the process of determining weight and mass is called weighing.
What is the difference between analytical balance and precision balance?
Precision and analytical scales are specific types of scales that measure masses much smaller than the average balance. The analytical balance is more accurate, as it has a higher readability, measuring the closest to 0.0001g. Analytical scales usually include draft-proof weighing chambers for accurate mass measurement and are often used alongside anti-vibration tables to increase accuracy.
A precision scale, on the other hand, usually measures to the nearest 0.1-0.001g, but has a higher capacity. It can measure capacities from hundreds of grams to kilograms.
The analytical balance is a model whose main characteristic is to provide an exact and specific weighing in relation to the weight of an object or a certain component. It is designed to measure small masses with great precision. They are extremely sensitive, capable of measuring four decimal places to the right of the decimal point (0.0001g) and capable of measuring samples up to 320g.
Due to its high sensitivity, the analytical balance should always be used in a totally closed and neutral environment. This is because variations in temperature, humidity, drafts and vibration can significantly change the reading results. Its main feature is a kind of glass chapel / door that avoids air turbulence and guarantees the fastest and most accurate results.
It is commonly used in several segments, such as handling pharmacies, laboratories, chemical industry, pharmaceutical industry, cosmetic industry, research and quality companies, among others.
Precision scales, also known as overhead scales, are capable of measuring up to 5kg. They are considered semi-analytical, since they are slightly less accurate than a standard analytical balance, with a legibility of up to three decimal places to the right of the decimal point (0.001gr). Used for measuring small samples, precision scales provide an accurate, quick and simple way to determine the weight of items such as particulate matter.
Because they are less sensitive to temperature fluctuations and drafts, precision scales do not require controlled rooms. Some models are equipped with the UniBloc mechanism, a Shimadzu brand differential, whose main characteristic is quick response, stability to temperature changes and high durability.
The precision scale is used by research and quality control laboratories in the pharmaceutical, chemical, food and textile industries, even educational institutions.
Applications of a laboratory precision balance include: simple weighing, dynamic weighing, sample preparation, statistical quality control, formulation and weighing by intervals. Highly accurate and reliable, a precision scale is the ideal option for any daily weighing task in the laboratory.