Shanghai Fangrui Instrument Co., Ltd. is a professional manufacturer of measuring instruments recognized by the Shanghai Bureau of Metrology and Technology Supervision. It has multiple national technical patents and produces various instruments with completely independent intellectual property rights.

　　

The company has a complete R&D, production, quality inspection, after-sales and other systems to ensure that every product produced meets the corresponding national and industry standards and can pass third-party technical inspections.

　　

The instrument comes with a one-year warranty, lifetime maintenance (at a cost), free software upgrades, and timely answers to various user questions, ensuring long-term safe use.

　　

This series of instruments has been awarded the latest national patent, patent number: 2011200652242.

Introduction to accuracy automatic calibration and temperature automatic compensation functions:

　　

At present, there are many manufacturers in China that produce surface/interface tension meters, and the models are diverse. However, except for the full series of surface/interface tension meters produced by Shanghai Fangrui Instrument Co., Ltd., almost none of them have advanced technologies such as "accuracy automatic calibration" and "temperature automatic compensation" that are only available in imported instruments and are very practical.

　　

The so-called "accuracy automatic calibration" refers to the automatic correction of the overall error of the instrument testing standard sample, using secondary distilled water (72.75mN/m at 20 ℃) and pure ethanol (22.3mN/m at 20 ℃) as standard samples. After accuracy automatic calibration, the measurement accuracy and repeatability of the whole machine can fully achieve:

　　

≤± 0.1mN (BZY-1)

　　

≤± 0.02mN (BZY-2)

　　

Domestic surface/interface tensiometers of the same type sold on the market generally have full-scale calibration, which is carried out using a weight equivalent to the maximum range (such as 200mN/m, 400mN/m). Regardless of the method used, only the sensor and circuit parts of the instrument can be calibrated. Full range calibration is necessary for measuring instruments, but it is also not comprehensive: an instrument that has been fully calibrated does not necessarily mean that the actual measured sample is accurate, because full range calibration does not take into account the measurement errors of key sensing components - platinum plates or platinum rings. Platinum plates and platinum rings have strict size and price requirements: Platinum plates require flatness, a certain degree of roughness on the surface, and sufficient wetting with liquids; Platinum rings require strict adherence to standards for wire thickness and diameter, as well as a standard circle.

　　

After using the instrument for a period of time, one may encounter the following situations:

　　

1. The surface of the platinum plate has worn, scratched, or slightly changed in external dimensions

　　

2. Platinum plate measurement contains particulate samples, which affect surface roughness

　　

3. The platinum ring is deformed, no matter how it is shaped, it is not round or the bottom is uneven

　　

4. The platinum plate and platinum ring are contaminated by the sample and cannot be cleaned by any method

　　

If the above situation occurs, it will definitely bring significant errors to the measurement accuracy, especially in situations with high requirements, which will have a greater impact. To solve this problem, according to past practices, one can only purchase platinum plates or platinum rings again. Now with the "accuracy automatic calibration function", this problem can be completely solved by testing secondary distilled water and pure ethanol, restoring the measurement accuracy of the instrument to the precise state at the factory, which not only improves the measurement accuracy of the instrument, but also reduces the operating cost of the instrument.

　　

It is difficult or impossible for similar surface/interface tensiometers sold on the market to achieve technical parameters of 0.1mN/m and 0.02mN/m due to the lack of "accuracy automatic calibration" function.