While many people use “scale” and “balance” interchangeably, understanding the differences between the two can influence your purchasing decision. In this blog, we’ll explore the distinctions between scales and balances and help you determine which one best suits your needs.
What is a Weighing Scale?
A weighing scale is a device that measures weight by detecting deflection. Mechanical scales, which don’t require electricity, use springs that stretch under weight.
The radial dial on these scales shows the amount of force needed to stretch the spring, which is then converted into pounds or kilograms. While you might still find spring scales in home bathroom or kitchen settings, they are considered outdated for professional use. Today, digital scales with load cells have become the standard in the market.
Load cells are transducers that convert the force or weight applied to them into an electrical signal. Typically made from aluminum or stainless steel, a load cell has an electrical current running through it. These metals are slightly flexible, causing the load cell to bend under weight. The amount of bending is detected by the electrical current, which is then translated into a readable value on the digital display.
Unlike spring scales, which measure deflection in a similar way, digital scales with load cells offer greater durability and accuracy. For example, our digital IHS 20a crane scale can handle weights up to 10,000 kg—something a spring scale would need to be extremely large to manage and could be dangerous if the spring failed. In contrast, the IHS 20a remains compact while providing precise measurements.
What’s a Balance?
Balances have a much longer history than scales—dating back several thousand years. In this blog, we explore the evolution of laboratory balances over time. Unlike scales, which measure deflection, balances determine unknown weights by comparing them against known weights.
A contemporary example of a mechanical balance is our TBB Triple Beam. Each beam on the TBB has adjustable weights that, when positioned correctly along the beam, achieve equilibrium with the weight placed on the pan. By adding the necessary weights to reach this balance, you obtain the measurement. The TBB is particularly useful in classrooms, offering a hands-on demonstration of the weighing process.
For professional applications, digital balances are the most commonly used. These balances perform the weighing process internally through a force restoration mechanism. This mechanism utilizes coils within a magnetic field to generate the precise force needed to balance the object. The amount of force required is then displayed as the final weight measurement.
Should You Opt for a Scale or a Balance?
Ultimately, choosing the right weighing machine depends on your specific needs for capacity and precision. Here’s a comparison of how scales and balances measure up in these areas:
Capacity
Most weighing machines with capacities exceeding a few kilograms are scales rather than balances. Examples include bench, floor, platform, and hanging scales, all designed to handle substantial weights.
Load cells are known for their durability, and, as demonstrated by our PT Platform Scales, some models feature multiple load cells. The PT Platform Scale, for instance, is equipped with four load cells—one in each corner. This configuration ensures accurate weight readings regardless of the item’s placement on the platform, allowing the PT to handle capacities ranging from 1,000kg to 10,000kg.
In contrast, semi-micro, analytical, and precision balances are designed for much lower capacities. Their force restoration mechanisms need to generate a precise amount of force to counterbalance the weight of the object, which is manageable when dealing with weights of just a few kilograms or less. For example, our Equinox EAB 125i Semi-Micro Balance has a maximum capacity of 62g, reflecting its specialized purpose.
Therefore, if you require a weighing machine with a high capacity, you’ll most likely be looking at scales rather than balances, and the opposite holds true for lower capacities.
Precision
Balances offer greater precision and accuracy than scales, with much finer readability. For example, the EAB 225i, despite its 62g capacity, can deliver results with a precision of 0.01mg. Even our least precise balances have readabilities of 0.1g or better, while still accommodating capacities up to an impressive 22kg.
In contrast, the IHS 20a Crane Scale, with its 10,000kg capacity, has a readability of 2kg. While the Equinox balances are ideal for tasks requiring extremely fine measurements, such as crafting medicines, the IHS Crane Scale is suited for weighing large items like shipping crates, where a 2kg readability is perfectly adequate.
Balances offer a higher level of precision, making them much more sensitive than scales. Due to their fine readability, simply using an open pan, as with a bench scale, may not suffice. The more precise the balance, the more precautions are needed to avoid external factors affecting your measurements.
For instance, many of our Highland HCB Portable Precision Balances come with a removable draft shield. While you can use the balance without it in a typical environment with minimal disturbances, it’s advisable to use the shield if you’re outdoors in windy conditions or in a busy classroom.
Our Equinox, Solis, and Luna Precision Balances have built-in, non-removable draft shields to protect against everyday air drafts that could impact results. Additionally, the Equinox, Solis, and Luna Analytical Balances also feature draft shields and are best used with an AVT Anti-Vibration Table and an ABI-1 Ionizer to address concerns about small vibrations and static. Conversely, for busy warehouses and factories, our CKT Bench Checkweighing Scales are designed to handle active environments effectively.
Whether you choose balances or scales, Adam Equipment guarantees a high-quality weighing machine. If you’re uncertain which model from our extensive range best suits your needs, our team is here to assist you. Feel free to reach out for guidance.
