# The Importance of Metrics

Metrics are best when they provide clear, quantifiable data that can be measured, tracked and analyzed over time. Metrics should also be focused on key areas of importance to your organization or project.

In physics, mass is a quantitative measure of inertia, the resistance that matter offers to change in velocity when a force is applied. It is measured in kilograms and fractions of a kilogram.

## Weight

Many people use the words “weight” and “mass” interchangeably. However, the two measurements have different meanings in physics.

The SI unit of mass is the kilogram (kg), and masses are measured in kilograms and multiples or fractions of the kg. The physical prototype of the kilogram is kept in a cylinder of platinum-iridium at the International Bureau of Weights and Measures.

In physics, mass is an intrinsic property of matter and does not depend on gravity. This is why you would have the same weight on Mount Everest or in orbit.

In contrast, weight depends on the force of gravity and changes depending on where you are. For example, you will have a very different weight on Jupiter than you will in your own backyard. Consequently, a balance-type weighing scale and a load cell-based bathroom scale will give you different readings for the same object. This is why scientists insist that you should only use precision mass standards to measure your own weight.

## Density

Density, defined as mass divided by volume, is a fundamental physical property of substances. It is essential to understanding and measuring the properties of all matter, including planetary bodies and stars.

For solids that have simple shapes, such as a cube or sphere, density is easy to measure by weighing the sample and dividing it by its geometric volume. This time-honored method is also effective for liquids.

In general, a substance with more mass in a given volume has higher density. Knowing density allows scientists to classify materials, and even predict their interactions with each other – like whether a certain oil will float or sink in water.

For partitioned solids such as powders and granules, density is determined using a digital or electronic hydrometer or pycnometer. Depending on the instrument, results can be expressed in different units and concentrations, which is useful for quality control or product development. In some cases, the instrument’s tare function can automatically convert results to standard units and concentrations.

## Volume

Students need to understand the differences between mass and volume, which is important for chemistry studies. For example, the same substance can weigh differently on Earth and in space because of different gravitational pulls.

Measuring the volume of a sample is a critical step in determining its density. Often the process is accomplished using displacement methods such as graduated cylinders, or volumetric flasks. The most commonly used unit of measurement for volume is the cubic meter (m3), which is derived from units of length. A liter, for example, is equal to 1000cm3 (1dm3).

The shape of a sample also affects its volume. Solids have very stable shapes and volumes, while liquids and gases have unstable shapes and volumes. For these reasons, it is essential to measure an object’s volume before measuring its weight to get an accurate picture of the matter inside. In addition, it is important to know that the same measurement of a container filled with different substances will yield different results due to the difference in their densities.

## Acceleration

The rate at which an object changes its velocity. Acceleration is one of the kinematic quantities (position, distance, speed and direction) that define motion.

A change in acceleration defines the rate of change of a body’s velocity, so it is also a measure of force. The quantity of force required to cause a given acceleration is called the mass of that object.

Sports announcers occasionally use the word “accelerate” to refer to someone moving fast, but in physics, acceleration has nothing to do with speed and everything to do with changing how quickly an object is moving. An object can have a constant speed, yet be accelerating, or even decelerating.

Using a ticker-timer attached to the trolley with a meter connected to it, students can actively observe that acceleration depends on net force, and that an increase in force leads to an increase in acceleration. This can be a useful introduction to the concept of proportionality, which states that two variables are related in such a way that when one variable increases or decreases, the other does the same.

# The Importance of Accurate Weighing

Whether you’re working in a lab or a manufacturing plant, weighing is a critical step. Inaccurate measurements can lead to expensive mistakes and delays.

Automated weighing systems can help improve efficiencies in the workplace. They provide streamlined processes that integrate seamlessly into existing manufacturing setups. They also come with features that manage data, crucial for inventory management and quality assurance.

## Accuracy

Weighing accuracy refers to the accuracy of a scale’s output and the consistency of its results. Linearity is a measure of the scale’s straightness; precision and repeatability are measures of how closely the scale reproduces its initial reading after repeated weighings under identical conditions.

A balance’s calibration and location can impact its accuracy. It should be calibrated on a regular basis with certified calibration weights, and the location should be well shielded from vibrations, temperature fluctuations and air currents.

To maximize your weighing system’s accuracy, select load cells and weight controllers with impressive worst-case specifications. Invest in high-quality components specially designed for your application and follow good housekeeping practices to minimize mechanical interference that can affect performance.

## Safety

Weighing chemicals is a critical process that must take safety precautions into account. The use of chemicals that are considered toxic or hazardous is not recommended, as they can pose health hazards for workers and can damage the environment.

Regular calibration and inspection of the weighing equipment help to ensure its functionality over time. This step is especially important in industries that rely on strict quality standards for their products, like pharmaceuticals and food.

Positioning your weighing instruments in a stable location helps prevent inaccurate measurements and drift caused by vibrations, temperature changes or air drafts. Avoid putting your balances near air conditioning systems or larger laboratory equipment, as they are more likely to cause these disturbances. Using laboratory-grade weighing paper prevents material from sticking and maintains accurate readings.

Weighing systems used in hazardous locations need to be equipped with special protection that prevents fire or explosion. Intrinsically safe circuits limit the amount of electrical energy available to provide enough sparks to ignite combustible fumes/gases and dust.

## Efficiency

Efficiency is the ability to complete a task without wasting resources like time, energy or materials. This includes avoiding mistakes that can occur during production, as well as minimizing wastes from overproduction or product defects.

Process weighing systems play an important role in maximizing operational efficiency. They help ensure that ingredients are weighed accurately to meet production specifications and quality compliance requirements.

Accurate weighing requires consistency, which means implementing a specific set of procedures and ensuring they are followed every single time. This also involves training your staff on how to use a new system so that they are comfortable with the processes and are not relying on the technology.

For example, when using an analytical balance, the sample should be added to a tared container and then placed on the pan. This allows the balance to “warm-up”, reducing some of the larger variations present in initial weighings and improving accuracy.

## Automation

For industries like food & pharmaceuticals, weighing accuracy is essential. Any mistakes at this point in the process can result in costly product recalls or health risks for consumers.

Automated weighing systems reduce labor costs & improve production efficiency by eliminating human error & providing consistent, accurate results. By integrating weighing into the larger manufacturing process, automated systems also help ensure compliance with quality standards & regulatory requirements.

Smart weighing automation systems like METTLER TOLEDO’s IND360 offer a standard automation interface (SAI) that facilitates easy integration into PLC control systems. This allows engineers to focus on leveraging advanced weighing features for enhanced data management.

Direct weighing minimizes handling & improves product quality by transferring data directly from the balance to the control system without reentry of manual data. This is particularly important in applications with harsh environments, where a high level of precision is needed. High-precision weigh modules can detect deviations of one part in a million to achieve this level of accuracy.