Laboratory balances
Laboratory balances are used to measure sample mass during research, quality control, formulation, sample preparation and production. The appropriate balance depends primarily on the required readability, weighing capacity, sample size and operating environment.
LabSPX supplies laboratories throughout Belgium, the Netherlands and Luxembourg with precision balances, analytical balances, semi-micro balances and microbalances. The range also includes moisture analyzers for determining moisture content through loss on drying.
What are the different types of laboratory balances?
The main difference between laboratory balances is their readability. Readability is the smallest change in mass that the instrument can display. As readability becomes finer, environmental influences such as vibration, air movement, temperature changes and static electricity become increasingly important.
Capacity must also be considered. A balance may provide very fine readability but only within a limited weighing range. The best choice therefore depends on both the smallest quantity that must be measured and the total mass placed on the balance.
Precision balances are designed for routine weighing tasks that do not require analytical or micro-level readability. Depending on the model, they typically display mass in increments from 0.001 to 0.1 g.
Their higher capacities make them suitable for larger samples, containers and formulation components. Many precision balances use an open, top-loading design, although draft shields may be fitted to models with finer readability.
Precision balances are commonly used for:
- General sample preparation
- Formulation and batching
- Quality control
- Raw-material weighing
- Counting and percentage weighing
- Laboratory and production applications
Apollo GX-A/GF-A Series
Precision balances with several functions for automated checking, weighing control, and documentation
Analytical balances typically provide a readability of 0.1 mg. They are used when laboratory work requires considerably finer resolution than a precision balance can provide.
These balances normally include a draft shield because air movement can affect measurements at this level. A stable surface and suitable environmental conditions are also important for repeatable results.
Analytical balances are suitable for:
- Preparing reference standards and solutions
- Quantitative sample analysis
- Pipette testing
- Pharmaceutical and chemical formulation
- Quality-control measurements
- Density determination
Semi-micro balances typically provide a readability of 0.01 mg. They offer finer resolution than standard analytical balances while retaining more practical capacities than most microbalances.
They are particularly useful when only small quantities of valuable or limited material are available. Their higher sensitivity means that vibration, air movement, temperature variation and static electricity must be carefully controlled.
Semi-micro balances are suitable for:
- Small-sample formulation
- Low-dose pharmaceutical work
- Research and development
- Reference-material preparation
- High-precision quantitative analysis
Microbalances provide readability down to 0.001 mg, or one microgram. They are designed for weighing very small quantities and detecting extremely small changes in mass.
Measurements at this level are highly sensitive to vibration, air currents, temperature changes and electrostatic charge. Microbalances therefore require controlled conditions and careful sample handling.
Microbalances are commonly used for:
- Filter weighing
- Trace analysis
- Emissions and particulate testing
- Material research
- Very small or valuable samples
Moisture analyzers combine a weighing system with an integrated heating unit. They determine moisture content by monitoring the change in sample mass during drying.
The instrument weighs the sample before and during heating. It then calculates the moisture result from the mass lost as water and other volatile components leave the sample. This loss-on-drying approach avoids using a separate drying oven and repeated manual weighing.
Moisture analyzers are commonly used for powders, granules, food products and raw materials. The appropriate test temperature, sample quantity and endpoint depend on the sample and method used.
How to choose a laboratory balance
Choosing a laboratory balance involves more than selecting the finest available readability. The balance must provide suitable performance for the sample, method and working environment.
Important selection criteria include:
- Required readability
- Maximum weighing capacity
- Minimum sample weight
- Expected measurement uncertainty
- Sample and container dimensions
- Calibration requirements
- Exposure to liquids, powders or dust
- Sensitivity to vibration, drafts and static electricity
- Data transfer and documentation requirements
- Cleaning and maintenance needs
For wet or dusty applications, a protected model such as the FXi-WP or Fortis WP may be more suitable. Applications involving very small samples may instead require a semi-micro or microbalance with draft protection and static-control features.
Not sure which balance fits your application?
Compare readability, capacity, calibration, and environmental requirements.