Schaller measurement technology expertise

What is meant by calibration and adjustment – ​​and why are both steps crucial for precise measurement results?

In metrology, two terms are frequently encountered that are often confused or even used synonymously: calibration and adjustment. Both are closely related in the handling of measuring instruments, but they fulfill different tasks. This distinction is crucial for the accuracy, reliability, and reproducibility of measurement results in practice.

Adjustment vs. calibration in humidity measurement technology – differences explained simply

Calibration is the comparison of a measuring instrument with a traceable reference standard to identify deviations.

The following applies: 

  • The device remains unchanged.
  • Only the deviation is determined.
  • The result is documented (e.g. in the calibration certificate).

For example:
A hygrometer is placed in an environment with exactly 75% relative humidity and displays 72%. This deviation is recorded but not corrected.

Calibration = Documentation

Adjustment is the targeted intervention in a measuring device to correct detected deviations based on a calibration.

The following applies:

  • Adjusting the measuring device to the target value
  • Intervention in software, electronics, or mechanics
  • Goal: Measured values ​​within the required accuracy

For example:
One device consistently displays a reading that is 3% too low. During calibration, it is adjusted so that the displayed values ​​are as close as possible to the reference value and within the tolerance.

Adjustment = Correction
Only the interplay of both tasks creates consistently reliable measurement results.

Its significance for use in measurement technology

Especially in humidity measurement, even small measurement deviations have a major impact:

  • Quality problems in production
  • Faulty material assessment due to moisture influences
  • unreliable laboratory and process data

Why even high-end moisture meters need to be calibrated and adjusted.

High-precision moisture meters do not directly determine the water content. Instead, they detect physical properties of the material and calculate the moisture value from these. They measure electrical or physical signals, which are then converted into a specific moisture value.

To ensure that this conversion remains consistently reliable, regular calibration and adjustment are essential. This is the only way to detect deviations and correct them precisely to guarantee the required measurement quality.

Calibration and adjustment are necessary because measurement conditions vary in practice and can therefore influence measured values:

  • The material being measured is rarely fully standardized.
  • Moisture is often determined indirectly via material properties.
  • Environmental and sample conditions (e.g., temperature, structure, density) are constantly changing.
 
 

Further information for consistently precise measurement results can be found here: Calibration and adjustments

Calibrate & Adjust