LAB Scales / Laboratory Scales

A laboratory without laboratory balances is hardly imaginable. Laboratory balances are a very important tool to reproduce, check and improve experiments. Very different tests and series of experiments can be carried out in the laboratory. The accents vary, depending on whether it is assigned to the product development or quality assurance in the pharmaceutical industry or in special machine construction. Therefore, heavy-duty scales as well as precision scales and fine balances are used as laboratory balances. The term "laboratory balances" is thus not limited to a specific type of the balances, but rather describes the environment in which the balances operate.

To find the right laboratory balances, the first step is to clarify for which applications the balances are to be used. Already at this stage, it becomes clear whether separate laboratory balances are sufficient for all the measurements in the laboratory or whether it makes sense to purchase several balances with different functionality or design. Once the requirements for the laboratory balances have been determined for all the measurement tasks, in most cases, the user can then decide on the design of the laboratory balances. From the bench scales as compact or platform scales, floor scales and suspended scales up to individual load cells with separate display unit, there are many variants in different sizes and with different capacities. The load capacity, i.e. the maximum load, the resolution and the required accuracy are more directly related to the scales of one series. Because the load cell signals for the applied load can only differentiate within a limited range, the number of the display options is limited. Laboratory balances with 3,000 divisions have a resolution of 1 g at a maximum load of 3 kg and 20 g at a maximum load of 60 kg.

For some applications, just the weight indication on the display of the laboratory balances is completely sufficient. For many applications, however, it is necessary to store and evaluate the measured data. In addition to the storage and transmission options, many laboratory balances also have additional functions that make the user's work easier. For this purpose, special calculation functions are stored in the laboratory balances, which can be called up via the control panel.

High accuracy is a feature that any customer expects from the weighing equipment. Depending on the function of the equipment, the required accuracy levels may differ from the expectations of the user. There is no place for measurement errors in the lab since all the tests and experiments must be carried out with high precision. Weighing is one of the most fundamental procedures performed in any medical or scientific laboratory. For modern lab scales, precision is vital and they must additionally possess features such as averaging, control weighing, piece-counting, and percentage weighing which makes them indispensable devices for researchers.

Laboratory research is often performed using small weights as well as various ingredient mixtures and materials. Therefore, the lab scales must be able to offer the smallest readability with numerical precision to the required decimal digits. Each laboratory must determine the minimum requirements and capacity needed for their application, since accuracy and readability are among the influencing price factors with the laboratory scales. Precision lab equipment should be protected from any possible harmful elements including dust, wind and vibration. Certain laboratory scales and weighing platforms are equipped with various auxiliary enclosures to provide full dust, wind, and vibration protection for the device and material being weighed.

Modern laboratory scales allow you to switch between different measuring units as well as utilize connectivity through a PC or other devices. Connectivity allows the user to see readings in real time, the capability of keeping a record of weighings or experiment logs, as well as easy preparation for detailed reporting. Depending on the type of laboratory and its required equipment, the lab scales may feature components such as an internal calibration function and overload protection. These functions are designed not only for continuous accuracy, but to protect the units internal systems. If a laboratory operates in compliance with the ISO or NIST requirements, government regulations, and specific industry standards, the operator must exercise particular care and observe specific rules to guarantee the lab scales and balances operate as designed. Laboratory equipment requires periodic care and maintenance due to its high sensitivity and precision accuracy.

When it goes about a laboratory, it is clear that approximation does not count and all the measurements should be as precise and accurate as possible. The first thing to remember is that it goes about accuracy and this should not be underestimated. Connected with this point is also specialization of the laboratory, because depending on what kind of tests and experiments are carried out there, the laboratory scales applied may also differ. In general, the laboratory scales may be analytical (with the highest precision class 1, 2), technical, microbalances, top loading weighung scales and others. There is simply no point to take the highest precision analytical balances for weighing materials where the highest accuracy is not necessary. Thus, for example, in metallurgical, heavy industries, agriculture, partly chemical and food industries, the laboratory scales weighing is often carried out not in the perfect ideal conditions (dust, vibration, wind) and the analytical balances may just be not the best choice. More robust models providing smaller accuracy, but provided with additional auxiliary equipment (weighing platform, windscreen, removable weighing pans) may serve for weighing samples of hot substances, oil, coal products without being damaged or broken. They are easy to maintain, clean and calibrate due to the automatic calibration function.

In their turn, analytical laboratory scales and balances are mostly used for especially precise measurements, where not only gram / pounds, but hundreds of a gram/lbs count. This applies mostly to pharmaceutical and medical sphere (preparation of solutions, testing of new substances, mixing of various component), jewelry production, chemical laboratories, food / beverages production (creation of new tastes and flavors), criminalistics etc. The requirements to this type of balances are very high and that is why these analytical devices should fully comply with the regulations of ISO and GLP. Depending on the accuracy a certain laboratory is certified for, the equipment used in this laboratory is strictly controlled. Compliance with all the requirements is important not only for the laboratory where the experiments are carried out, but at all the further stages the product goes through: developing, processing, manufacturing, packaging, storage… The main goal is – the final product which in this or another way reaches the customer should correspond to the existing required standards. That is why GMP (Good Manufacturing Practice) or BRC Global Standards, which, principally, monitor and control that the producer observed all the rules at any stage the product goes through, in order the customer / consumer received qualitative product, set very high requirements which are obligatory for fulfillment.

To use these scales and balances, the perfect conditions must be provided: absolutely clean air, no contaminants, like dust or particles of other substances, cleanness, absence of vibration, air flow, draft. If some of the parameters cannot be fulfilled, like very clean environment, the lab scales need to have a special protection class, which correspondingly prevents contaminants from getting inside and influencing the measurements. It mostly goes about weighing samples of bulk or liquid test reagent, chemical agents with the purpose to determine very precise weight, up to 5th decimal place. This type of laboratory scales and balances may be used only be the trained personnel and the equipment should be installed on a special anti-vibration laboratory table, so that any possible influence on the measuring process was excluded. Nowadays, the latest models of the laboratory scales / lab scales possess a special interface – this feature provides the connection to the computer and a very good possibility to process and analyze the results of the measurement at once. All the data are stored and the influence of the human factor is almost brought to zero. Due to the software, the data cannot be confused, misread or lost, and almost all necessary calculations are carried out automatically. Laboratory scales / lab scales must be calibrated regularly, especially the analytical ones, in compliance with the directives concerning quality control. The slightest changes in the environment (temperature, humidity, air moves, pressure) are likely to affect the weighing equipment and thus, to ensure perfect measurement results. Calibration may be external and internal, can be carried out manually by the trained operator or automatically, if there is such a function available. Laboratories that comply with ISO / GLP or GMP are recommended to carry out external calibration daily to avoid measurement errors of any kind and to ensure high precision.