Class A vs. Class B Volumetrics – When to Spend vs. Save

Laboratory budgets are often tight, and consumables such as volumetric plasticware and glassware can represent a significant expense over time. While it may seem cost-effective to choose the less expensive option, understanding the differences between Class A and Class B volumetric instruments ensures that accuracy and reliability are not compromised. Choosing the right class depends on the type of work performed, the required precision, and the level of documentation your procedures demand.

Understanding Volumetric Classifications

Volumetric glassware and plasticware are classified according to accuracy standards established by organizations such as ASTM, ISO, and DIN.

• Class A volumetrics are manufactured with the most stringent tolerances, ensuring highly precise volume measurements. These items are often individually calibrated and may include serial numbers and certificates of accuracy.
• Class B volumetrics are built to broader tolerance limits—typically allowing about twice the permissible error of Class A instruments. They are well-suited for general use but are not intended for critical analytical applications.

The distinction between the two classes is not about basic functionality—both are capable of measuring volume—but rather about how reliably and repeatably they can do so.

When to Choose Class A

Class A volumetrics are essential in laboratories where measurement precision directly affects experimental outcomes.
These include:

• Analytical and quality control laboratories performing titrations, dilutions, or standard solution preparations.
• Regulated environments (such as pharmaceutical, environmental, or food testing labs) that require traceability and documented accuracy.
• Research settings where small variations in concentration can alter reproducibility or invalidate results.

In these cases, investing in Class A instruments is a matter of scientific integrity. Each item’s calibration certificate provides traceability to national or international standards, simplifying audits and compliance with ISO or GLP/GMP systems.

When Class B is Sufficient

Class B volumetrics are designed for routine, non-critical measurements where small variations in volume are acceptable.
Typical uses include:

• Educational laboratories, where students learn volumetric techniques.
• General solution preparation or reagent mixing where tight tolerances are unnecessary.
• Non-regulated research or industrial applications prioritizing throughput over analytical precision.

Because Class B items are more affordable, they allow laboratories to stretch their budgets without sacrificing usability in contexts where precision is not the deciding factor. However, users should note that these items lack individual calibration data and are not typically certified for traceable accuracy.
 

Material Considerations

Beyond accuracy class, the material composition of volumetric instruments can influence both performance and longevity.

• Glass volumetrics (such as borosilicate glass) provide excellent chemical and thermal resistance and are ideal for most solvents and strong acids or bases.
• Plastic volumetrics, like those made from PMP, PP, or PFA, offer durability and safety in environments where breakage is a concern. However, plastic materials vary in chemical compatibility—PFA offers high resistance, while PP and PMP are more limited.

Selecting the correct material ensures compatibility with your reagents, reduces contamination risks, and extends the useful life of your equipment.

Practical Guidance

When evaluating which volumetric instruments to purchase, consider the following questions:

1. What level of precision does my application require? If your results are used for quantitative analysis or compliance reporting, choose Class A.

2. Is traceability or certification necessary? Regulatory or ISO-accredited labs typically require documented calibration.

3. How frequently will the item be used, and with what chemicals? Material compatibility and durability may justify investment in higher-quality glass or PFA plastic.

4. Is cost savings or convenience the priority? For teaching or general-purpose labs, Class B may offer an optimal balance.

BRANDTECH Scientific Volumetric Options

BRAND glass volumetric instruments and VITLAB plastic volumetrics provide solutions for both high-precision and general-purpose applications.

• Class A items are available with or without calibration certificates for traceability.
• Class B options maintain solid accuracy for everyday laboratory work.
• A wide range of materials ensures compatibility with diverse chemical environments and temperature conditions.

Together, these options help laboratories make informed, data-driven decisions—balancing accuracy, safety, and budget requirements.
For more information, visit:
https://shop.brandtech.com/en/volumetric-instruments.html