Tools & Microfiber1 min read

Pendant-Drop Measurements: Image Scale Is Part of the Result

A pendant-drop surface-tension calculation uses the actual dimensions of the drop. An attractive image without a valid scale is not enough to produce a defensible result.

Updated · NANOLAB Knowledge

The key distinction

KRUSS explains that image calibration is required for this method. The laboratory should retain its scale setup and measurement record, especially when camera settings or the optical arrangement change.

Practical checks

  1. Confirm the instrument's scale-calibration procedure was followed.
  2. Preserve the original image and analysis settings.
  3. Recheck comparability after relevant optical changes.

Example

Illustrative example: a drop image is resized for a presentation and later reused as if it were the original measurement image. Without the correct scale information, the calculation may no longer represent the recorded experiment.

Scope and limits

Do not calculate surface tension from a casual bottle or droplet photograph. Use an appropriate instrument and validated method for the actual liquid and measurement question.

Related guidance

Technical references: KRUSS: pendant-drop method. These sources describe their stated methods or products; they do not certify NANOLAB products or establish compatibility with an unlisted surface.

Ask NANOLAB about the exact product and intended use. Use the current product documentation for formulation-specific instructions.

Tools & Microfiber1 min read

Micrometres and Nanometres in Coating Reports: Check the Scale

One micrometre equals one thousand nanometres. Preserve the unit when comparing a film-thickness result with a particle-size statement; the numbers may describe both different scales and different physical quantities.