What is the difference between an analytical balance and a precision balance?

An analytical balance provides readability of 0.1 mg or better, while a precision balance typically reads to 0.001 g or 0.01 g. Analytical balances include draft shields and are designed for highly sensitive measurements. Precision balances handle larger samples and are less affected by environmental conditions.

What readability do I need for my lab application?

You need a readability that is at least one-tenth of your smallest sample weight or required measurement increment. For example, measuring 100 mg samples may require 0.01 mg readability, while gram-level work may only need 0.01 g. Selecting higher readability than necessary increases cost without improving results.

Do lab balances need to be calibrated?

Yes, all lab balances require regular calibration to maintain accuracy. Calibration ensures measurements remain traceable to certified standards. Internal calibration simplifies this process by automating adjustments, while external calibration requires manual verification with certified weights. In regulated environments, calibration records must be documented and retained.

What is the difference between readability and repeatability?

Readability is the smallest increment of weight a balance will display. Repeatability is the degree of agreement between multiple measurements of the same mass, on the same balance, under the same conditions.

What is the best way to clean my balance to ensure accurate readings?

Inspect and clean before each use. A flannel cloth or soft brush works well for dusting and light cleaning. Use a non-abrasive cleaner for light spills, and a dry flannel cloth for glass parts. Set a regular maintenance schedule for deep cleaning to ensure optimal performance and instrument longevity.

Can vibration affect the accuracy of my balance?

Yes — even slight vibration from a heavy footstep can affect accuracy. Place the balance on a sturdy benchtop away from high-traffic areas such as hallways, elevators, stairways, and doors. If that placement is not possible, an anti-vibration table should be considered.

What Makes a Cleanroom a Clean Room? (Part 1)

This is part one in a two-part series on clean rooms.

Imagine if the medication we ingest and the electronic components we use were produced in rooms populated with chemical vapors, dust, and airborne particulates. These impurities would settle on capsules and circuits and contaminate them. Instead, manufacturers create a controlled environment—a cleanroom—to limit exposure to contaminants.

While not always sterile, a cleanroom follows accepted standards for maximum particulates per cubic meter. Air is filtered in and recirculated through HEPA air filters. Equipment is designed to generate minimal air impurities. Employees wear gloves, face masks, and head covers. Often, donning jumpsuits or smocks is also necessary. The room is cleaned daily, sometimes every few hours, according to rigorous quality procedures.

ISO Cleanroom Standards

The most commonly used standard for cleanrooms is the Federal Standard 209E. This standard refers to several classes of cleanrooms and correlates with ISO 14644-1 classes as well. For example, typical room air, classified as ISO 9, contains more than 35 million microns of particulates per cubic meter. By contrast, a Federal Standard 209E Class 100 (ISO 5) cleanroom contains a maximum of only 3,520 microns per cubic meter of particulates.

Higher purity cleanrooms raise the standard even further. A Federal Standard 209E Class 1 (ISO 3) cleanroom holds a maximum of only 35 microns per cubic meter of particulates. Consult the Institute of Environmental Sciences and Technology (iest.org) for updates in standards.

Read about what it takes to keep a clean room clean in the next blog. View our selection of Critical Environment Equipment and Supplies for Cleanrooms.

What Makes a Cleanroom a Clean Room? (Part 1)

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