Weighing is a critical part of many manufacturing processes. It is used for level or inventory monitoring, bag or drum filling and dispensing, batch weighing, simultaneous blending of multiple ingredients, and measuring and controlling mass flow.
Accurate weighing results are essential for high quality QC and production. However, a number of factors contribute to the measurement uncertainty. This includes the balance or scale itself, the reference weights used for calibration, the environment, and the operator.
Mass
Mass (symbolized m) is the quantity of matter that is contained in an object or particle. It is the base unit of the International System of Units (SI) and can be measured in kilograms.
The quantity of mass that can be determined in a sample is dependent on the size of the item and its density. In general, objects that are smaller have more mass than larger items.
Mass is measured in a balance using a mechanical weighing instrument. To obtain accurate measurements, the balance must be calibrated with a standard mass. The standard mass is placed on one of the pans of a balance, and then the object to be weighed is placed on the other pan. The masses on both pans are then compared until they are equal.
Weight
Weight is a physical concept that measures the force of gravity on an object. It’s used in a wide variety of industries, from construction to shipping to food service.
It is important to consider weight as part of your weighing process because it can affect the accuracy and reliability of your weighing system. It can also impact the quality of your products.
The best way to achieve a high level of accuracy is to select a top-quality load cell that uses strain gauges to convert the mechanical force of your load into an electrical signal. An improperly applied load can cause the strain gauges to experience a strain (increased resistance) instead of sending a proportional electrical signal that represents your load’s weight.
Good laboratory techniques and practices are essential for accurate mass measurements, but errors can be introduced by air currents, balance drift, lack of thermal equilibrium, magnetic or electrostatic fields, and manipulation of the balance. These sources of error can be reduced or eliminated with different weighing methods, sensitivity weights, and by controlling environmental factors that can affect the accuracy of your weighing system.
Volume
Weighing is a useful method for measuring dry bulk material quantities and flowrates. It can be used to measure a variety of different materials without correction factors for their mass density, which means it can be particularly effective for corrosive materials or those that are sensitive to temperature and pressure changes.
While weighing is an excellent way to measure dry bulk material volumes, it can be inaccurate if it’s not applied correctly or when the sample is subjected to environmental factors that may impact its accuracy, such as a slight change in temperature or wind pressure. For this reason, it’s important to take steps to ensure that your weighing system is operating properly and that the sample remains chemically inert throughout the process.
Volume is a three-dimensional quantity that measures the capacity of a closed shape, or the amount of space it can occupy. It’s measured in various units including cubic meters (SI derived), liters, and milliliters.
Temperature
In the weighing process temperature is an important factor. It measures the average kinetic energy of particles in matter and as the particles move faster the kinetic energy increases which increases the temperature.
Temperature is a measurable physical property of an object that can be considered in conjunction with other measurable properties such as mass and density. It can also be written in an equation as a ratio of extensive properties.
The simplest and most common definition of temperature is the average translational kinetic energy of molecules, which are typically thought to act like independent point masses. In materials such as monatomic perfect gases and simple metals, this mechanical interpretation of thermal motion is useful.
In some cases, however, the molecules may be organized into a complex structure with internal or coordinated motions that may have kinetic energy as well. This may be a more suitable description than the simple mechanical one in which the temperature is simply the mean particle translational kinetic energy.