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.

How Do You Measure the Growth of Biological Agents?

In microbioloogy, use cell density photometers to measure the growth rates of E. coli, yeast cells, and other biological agents. These portable cell density meters analyze samples as small as 20µL and are compact enough to place inside incubation chambers, anaerobic compartments, or other environmentally controlled areas. They are dedicated to measuring cell densities in suspension.

How Cell Density Photometers Work

Cuvette Sample Site Cell Density Photometer

The photometers measure % transmission (% T) and logarithmic transmission absorption (Abs), and include an intervalometer for time-lapse recording. A 600 nm LED light focuses on the sample through fiber optic cables to get readings quickly.

Built-in controls operate the meter along with a touch-screen panel that offers various functions. For further analysis, data can be extracted and downloaded to a computer.

View our selection of cell density photometers.

How Do You Measure the Growth of Biological Agents?

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