Whether you're working with concrete, asphalt, aggregates, or soil, one thing remains non-negotiable: accurate weight measurements. Every construction materials test you perform—whether for compliance or quality control—depends on the precision of your weighing equipment.
So how do you choose the right lab balance or scale that meets both technical requirements and daily workflow demands?
This guide walks you through key selection factors like capacity, readability, accuracy, and advanced features such as internal calibration and data logging. Plus, we’ll help you understand the subtle differences between scales and balances—so you can make an informed investment in equipment that delivers long-term reliability and compliance with ASTM, AASHTO, or ISO standards.
Scales and Balances, Is There a Difference?
Although the phrases are frequently used interchangeably, there are several differences between scales and balances. In the most basic way, balances measure mass, or the amount of substance in an item, whereas scales measure the force of gravity acting on that mass.
Calibrating a scale at a specific place on Earth eliminates the effect of gravity, allowing force measurements to be stated in mass units such as pounds or kilograms.
Balances have traditionally used more complex mechanisms or sensors to precisely balance smaller masses. Scales use simpler, less sensitive technologies yet have a larger capacity for heavier things.
Nowadays, advances in electronics extract more range, precision, and sensitivity from more advanced sensors, blurring the lines between equipment.
For most applications of construction materials testing, there are few differences to mention between the two classes of devices. Manufacturers and users tend to use the terms balance and scale interchangeably, and that is how they are applied in this article.
The key consideration when choosing any weighing instrument is that it has the capacity, sensitivity (readability), and accuracy required by the test method.
Digital vs. Mechanical Lab Balances: Which Is Right for Your Testing Lab?
For years, mechanical balances have been the workhorses of soil and concrete laboratories, providing simplicity and reliability. However, today's electronic lab scales are rugged, ISO-certified, and filled with features such as internal calibration, multi-unit display capability, and data logging.
In most construction material testing (CMT) settings, a digital lab balance provides quicker readings, greater readability resolution (e.g., 0.01g), and improved integration with reporting systems. Mechanical lab scales remain adequate in remote field labs where battery-free operation is priority.
Scale & Balance Features: Mechanical vs. Digital
|
Type |
Power Source |
Accuracy |
Operation |
Weigh-Below Option |
Data Handling |
Units of Measure |
|---|---|---|---|---|---|---|
|
Mechanical |
N/A |
Adequate |
Slow |
Limited |
Weight Indication |
1 or 2 |
|
Digital |
Battery or AC |
Good |
Fast |
Yes |
Weighing Taring Data Collection, Internal Calibration, Calculating, Reporting, Printing. |
Up to 16 Selectable Units |
NOTE: Not all features shown are available on all digital scales or balances.
Mechanical scales are simple and robust, with no need for an electrical power supply. Still, digital balances now have the clear advantage for speed, accuracy, versatility, features, convenience, and, for many acceptable models, lower cost.
Kadeer Brothers Lahore still offers mechanical scales as part of our complete range of weighing products, but we recommend electronic digital models for accuracy, reliability, and workflow efficiency.
Aligning Balance Features With CMT Lab Needs
Not all lab balances are created equal. For testing applications in asphalt labs, cement plants, or geotechnical labs, you need a scale that meets not just capacity and readability specs—but also environmental and workflow needs. Look for features like:
- Overload protection (to prevent damaged load cells)
- Weigh-below hooks (for determining bulk density and specific gravity)
- Selectable weighing units (grams, kilograms, pounds, ounces)
- Compact footprints for tight lab benches.
Capacity
Deciding on a maximum capacity for a new scale might not seem complicated, but it is worth some extra thought. Setting an upper limit that is too high may sacrifice accuracy or readability. However, a little extra capacity could make the device functional for other applications.
A good rule of thumb is to select a scale that weighs your heaviest samples in the middle of its range. Applications requiring enhanced readability at higher capacities also require more sophisticated load cells, which increases cost. Be sure to include the weight of scoops or containers, although many electronic scales accommodate a tare weight separately from the rated capacity.
Readability
As noted earlier, readability is the smallest division of mass that the scale can display; however, it is not the same as accuracy. A scale with 0.1-gram readability displays the mass measurement to the nearest one-tenth gram.
Scales with large weight capacities often have lower readability. Models with advanced electronics may offer better readability, but opting for extra decimal places may needlessly increase the purchase price. The scale just needs to meet the specified requirements of the test method.
Platform Size
Dimensions of the weighing platform are often overlooked in the selection process, but daily operation may be difficult with the wrong size platform. A small platform might be fine for a flask or small container but entirely unsuitable for weighing material in a large, loose bag.
Weighing Units
Finding a balance or scale that weighs in specific mass units used to be much more of an issue than it is today. Mechanical balances are purpose-built for measurements in a single unit of measure, although some models are equipped with a dual scale.
Users of today’s modern digital models can choose to display results in a dozen or more selectable units on the same device. A scale with selectable weighing units of grams, kilograms, pounds, and ounces is suitable for weighing in most construction materials tests.
Application and Environment; Refining Your Choices
Once you have met the test method and specification requirements for a new balance, you can consider the variables on where, why, or how it is to be used. Comparing the characteristics of your front-running devices ensures satisfaction with the final choice.
Versatility: Is the balance needed only for a single application, or would a few more features make the device suitable for a broader range of tests? Power supply: Does the scale need to be in a particular location near an electrical outlet, or would a battery-powered model be more portable and adaptable? Workspace: Would a compact footprint allow easier operation in a confined area? Display Location: Will the dimensions or positions of the samples make the display difficult to see? Should the display be mounted in a remote location? Damp or dusty environments: Should you look for a model rated to resist environments that are dusty, dirty, or wet? |
Digital balances have a range of innovations to ensure that their use is efficient and easy. Models by various manufacturers could have innovative functions or provide them as optional additions.
Internal Calibration
Periodic calibration guarantees the continued accuracy of the balance. Conventional scals are calibrated for accuracy by using a sequence of traceable and certified calibration masses and adjusting the mechanism accordingly.
Internal calibration is a newer balance feature that employs an internal mechanism or circuitry to load the balance with a prescribed weight to verify and adjust calibration. If tracking and documenting calibration is required, this useful feature saves the extra cost and hassle of having additional calibration masses.
Weigh-Below Capacity
Suspended weighing capability enables a sample to be weighed in water for specific gravity, bulk density, or unit weight determinations. Scales with this capability have a built-in hook on the bottom to enable the attachment of a wire to hold weighing cradles or baskets. The balance is placed on a table or shelf with a hole to allow the wire to pass through. The test sample is suspended in the water held in a tank or bucket below.
Overload Protection
Extremely overloading a scale with excessive mass has the potential to permanently destroy the weighing mechanism or load cell. Overload-protected balances electronically shut off load measurements and give an error indication for an overload situation.
Elemental Protection
Scales operating in harsh environments must be protected against dirt and moisture to provide accurate performance and exended service life. There are dust and moisture-rated models, and there are even some wash-down-rated models that may be rinsed with a hose. A rugged carrying case is available for many models for traveling protection.
Portability
The best place to utilize a scale or balance is not always near an electrical outlet. You might be required to employ your scale away from the laboratory. Rechargeable or replaceable battery operation and a tough carrying case provide safe usage anywhere.
Data Collection
Some electronic scales have the capability to gather weight information for printing or integration with software programs on your computer. Electronic data enables you to design and print mistake-free spreadsheets and reports or convert calculations to graphs to present results.
Weighing Options; an Alternative to Conventional Scales
Suspension scales, sometimes known as crane scales, are commonly overlooked for laboratory use but yet play an important role in construction materials testing.
Large, bagged soil or aggregate samples are immediately weighed in the lab or field using any acceptable suspension point to ensure that the sample mass meets testing standards. Each model's remote control enables for safe zeroing, taring, and weighing unit selection.
Suspension scales are extremely portable and useful for properly weighing any large, irregular material.
Maintaining Accuracy and Precision
The calibration of balances and scales is part of the regular maintenance of laboratory equipment. Scheduled calibration and frequent temporary checks assure reliable test findings and timely records for audits. Kadeer Brothers Lahore offers ASTM calibration masses ranging from 0.001g to 250kg.
Sample Handling
Granular or powdered materials are difficult to handle and weigh unless they are in a scoop, chute, or tray.Weighing and Handling Scoops are useful for preventing sample loss.
We hope this blog post helped you choose the correct lab balance or scale for your testing purposes. Contact our testing experts to discuss your specific application.
Kadeer Brothers Lahore's digital lab scales and balances accommodate capacities ranging from 120g to 300kg, with models appropriate for:
We also offer mechanical balances, suspension scales, and portable weighing solutions for fieldwork.
Testing Resources
Standard Test Methods, Specifications, and Practices
Individual test methods and specifications referenced in our product descriptions, blog articles, and videos are available for review or purchase from the professional organizations noted.
- ASTM International(American Society for Testing and Materials)
- AASHTO(American Association of State Highway and Transportation Officials)
- ISO(International Organization for Standardization)
- BS(British Standards)
- EN(European Standards)