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.

Centrifuges: Getting the Centrifuge You Need (Part 1)

It’s hard to find a research lab without a centrifuge to process samples. In cellular and molecular biology, centrifugation is used for isolating cells, subcellular organelles, and macromolecules. In pharmaceutical studies and drug discovery, centrifuges are used in bioproduction, vaccine production, and metabolism studies. In food processing, this versatile instrument removes inbound moisture, filters particles, and ensures the quality of products.

Centrifuges separate colloidal particles and simulate gravitational effects to settle materials according to density. For a unit that achieves what you need it to, try these features:

Anticorrosive material: Carbon fiber is durable and lightweight, and will hold up longer over time than metal or aluminum components.
Biocontainment rotors: To maintain biosafety and reduce the risk of contamination, biocontainment rotors with click-shut lids keep the samples from spilling inside sealed buckets as they are loaded.
Glove-friendly: The front panel and rotor exchange don’t snag your lab gloves. Allows users to change rotors with ease. Models with click-shut lids offer one-handed operation.
Refrigeration: Eliminate any heat damage to samples by keeping the interior cooled with refrigeration.
Rotor balance protection: Alerts users to imbalances resulting from improperly installed rotors or samples placed unevenly. Once detected, the function will shut the centrifuge down.
Rotor versatility: Select a swing-out rotor when you want sample tubes to move from vertical to horizontal once the centrifuge speeds up. This type works well for cell culturing applications which leave sediment at the bottom of the tube. Fixed-angle rotors stay intact and typically work faster than swing-out rotors. To perform multiple tasks, choose a centrifuge that accommodates a variety of adapters. Select a model that doesn’t require the use of tools to change out rotors and adapters and is ergonomically sound.

For types of centrifuges, read Part Two of this two-part article. Need help selecting a centrifuge? Call 1-800-323-4340 and talk to one of our product specialists.

Getting the Centrifuge You Need: Part 1

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