What is a colorimeter
A colorimeter turns subjective "by eye" colour assessment into a repeatable number. We explain the operating principle, benefits and typical applications.
Operating principle
A colorimeter is an instrument for objective colour measurement. It illuminates the sample with a standardised light source and measures the reflected light in three channels through filters that mimic the sensitivity of the human eye (the tristimulus values X, Y, Z). From these it computes colour coordinates — most often in the CIE L*a*b* space — and the ΔE colour difference relative to a standard.
As a result, “pass/fail” assessment no longer depends on the observer, the lighting or eye fatigue, but becomes a repeatable numerical criterion.
Benefits
- Objectivity — the same colour gives the same result, regardless of person and conditions.
- Speed and simplicity — a measurement takes a second and operation is intuitive.
- Repeatability — easy batch-consistency control against a standard.
- Low cost — a colorimeter is cheaper than a spectrophotometer and is enough for many quality-control tasks.
Keep the limitations in mind: a colorimeter does not measure the full reflectance curve, so it cannot detect metamerism and is less versatile than a spectrophotometer. More in the article colorimeter vs spectrophotometer.
Applications
Colorimeters suit fast colour control in the production of plastics, textiles, paints, coatings, packaging, food and cosmetics — anywhere you need to quickly confirm colour conformity to a standard. See our NR- and NH-series colorimeters.
Frequently asked questions
What does a colorimeter measure?
A colorimeter measures colour in three channels (tristimulus X, Y, Z) and converts it into coordinates, most often in the CIE L*a*b* space, and into the ΔE colour difference relative to a standard. It objectively assesses colour conformity.
What are the benefits of a colorimeter?
Objectivity, speed, ease of use, repeatability and a lower cost than a spectrophotometer. It is a good tool for controlling batch consistency against a single standard under fixed conditions.
When is a colorimeter not enough?
When you need to build colour recipes, detect metamerism or work under different illuminants — a spectrophotometer is then better, as it measures the full reflectance curve.