The actual measurement error of the spectrophotometer will be affected by factors such as the nature of the sample, measurement conditions such as temperature, humidity, environmental interference, etc., and the skill level of the operator.

The measurement error of spectrophotometer is usually affected by many factors. In general, the error range is as follows:

I. Photometric error

1. Low-precision spectrophotometer: The photometric error may be around ±2%, for example: the basic spectrophotometer used in teaching experiments.

2. Medium-precision spectrophotometer: The photometric error is usually between ±0.5% and ±1%. This type of spectrophotometer is common in general laboratory analysis and can meet the requirements of most routine analyses.

3. High-precision spectrophotometer: The photometric error can be controlled below ±0.2% or even lower, and is mainly used in scientific research, quality control and other fields that require extremely high measurement accuracy.

II. Wavelength error

1. General spectrophotometer: The wavelength error is usually around ±1nm to ±2nm. For most routine analyses, this wavelength error range is acceptable.

2. High-precision spectrophotometer: The wavelength error of some high-end spectrophotometers can be controlled below ±0.5nm. In some analyses that require very high wavelength accuracy, such as medicine analysis, material science research, etc., such high-precision instruments are used.