Ordinary instruments: These instruments are mostly suitable for conventional qualitative or semi quantitative scenarios that do not require high measurement accuracy. Taking the contact angle measuring instrument on a platform of Shanghai Jiao Tong University as an example, its contact angle testing accuracy is ± 1 °, which can meet the basic requirements of preliminary determination of material surface hydrophilicity and hydrophobicity.

Mainstream precision instruments: This is a widely used type in laboratory and industrial testing, with an accuracy of ± 0.1 °. For example, the Global Hengda SCI5000A model has a contact angle accuracy of ± 0.1 ° when measured using the θ/2 method; The relevant instruments on the Hong Kong University of Science and Technology (Guangzhou) shared platform also have a measurement accuracy of ± 0.1 °. In addition, the calibration device for optical contact angle measuring instruments established by the China Institute of Metrology has an extended uncertainty of 0.1 °, which indirectly reflects that ± 0.1 ° is the core accuracy standard for mainstream precision measurement.

Partial ultra high precision instruments: These instruments are suitable for scientific research and other scenarios that require strict data accuracy, and the measurement accuracy can reach 0.01 °. Like the Yingnuo CA100D contact angle measuring instrument, the contact angle measurement accuracy is marked as 0.01 °. It is equipped with high-performance industrial digital cameras and high-resolution lenses, and also supports full range calibration function to ensure accuracy; The resolution of some high-end instruments can even reach 0.001 °, further improving the precision of measurement data.