Electrical conductivity is an important parameter for measuring the electrical conductivity of a material and is widely used in water quality monitoring, industrial production, and scientific research. To ensure the accuracy and reliability of conductivity measurements, calibration and verification using conductivity standard solutions are necessary.

A pH standard solution is a buffer solution with a known and stable pH value used to calibrate pH meters or pH electrodes. It is commonly used in laboratories, industrial production, and environmental monitoring to ensure the accuracy and reliability of pH measurements.

Turbidity standard solution is a reference substance used to determine the degree to which suspended matter in water obstructs light transmission. Its turbidity value is based on formalin, and the turbidity standard solution provided complies with ISO 7027 international standard and national standard.

An ORP meter, also known as an online oxidation-reduction potential analyzer, is an instrument widely used in industry and laboratories. ORP, as a comprehensive indicator of the environmental conditions of media (including soil, natural water, and culture media), has been used for a long time, characterizing the relative degree of oxidizing or reducing properties of the medium. The unit of ORP is mV. The ORP value (oxidation-reduction potential) is an important indicator of water quality. Although it cannot independently reflect the quality of water, it can be used in conjunction with other water quality indicators to reflect the ecological environment of an aquarium system.