At present, the domestic production of surface / interface tension meter manufacturers have a lot of surface / interface tension meter model is varied, but in addition to Shanghai Fang Rui Instrument Co., Ltd. produced a series of surface / interface tension meter, no one has a " Accuracy of automatic calibration "" temperature automatic compensation "these international advanced and very practical new technology.
The so-called "accuracy of automatic calibration" is the instrument test standard sample of the overall error automatically corrected to secondary distilled water and pure ethanol as the standard, and the literature value of the error can be achieved: ≤ ± 0.2mN / m (BZY series, QBZY-1 type), ≤ ± 0.04 mN / m (QBZY-2 type), ≤ ± 0.02 mN / m (QBZY-3 type).
All surface / interfacial tension gauges are generally full scale calibrated, no matter what method, only the circuit part of the instrument can be corrected, that is, with a standard weight of the weight to replace the measured value of the sample. Full-scale calibration is necessary for the instrument, but it is not comprehensive: the full scale calibration of the instrument, does not mean that the actual test sample is accurate. This is because full-scale calibration does not take into account the test error of the sensing element - platinum plate or platinum ring. Platinum plate or platinum ring has a strict size and processing requirements, the platinum plate requires smooth, the surface has a certain degree of roughness, with the liquid full wetting, contact angle is zero; platinum ring platinum wire diameter, Related standards, but also requires a standard circle.
The instrument factory carefully adjusted, should be able to meet the provisions of the factory standard, but the use of a period of time? How many will encounter the following situation:
1. Platinum plate surface with wear, scratches or dimensions have changed a little
2. Platinum ring deformation, no matter how plastic surgery is the whole round or the bottom of the whole uneven
3. Platinum or Platinum ring no matter what method is not clean wash
The above situation, will certainly have a greater error on the test accuracy, high precision in the test case, the greater the impact. To solve this problem, follow the previous practice, only to re-purchase platinum plate or platinum ring. Now with the "accuracy of automatic correction" this function, just test the secondary distilled water and pure ethanol to re-calibration of the instrument, you can solve this problem. Which improves the instrument's test accuracy and reduces the instrument's cost.
For this calibration, the standard sample needs to be kept at 20 ° C. According to the literature, the surface tension of the secondary distilled water at 20 ° C is 72.75 mN / m, and the surface tension of ethanol at 20 ° C is 22.3 mN / m. After a simple operation, the accuracy of the instrument can be calibrated to the exact state of the factory, can meet the technical requirements of the instrument requirements, that is ≤ ± 0.2mN / m (BZY series, QBZY-1 type), ≤ ± 0.04 MN / m (QBZY-2 type), ≤ ± 0.02 mN / m (QBZY-3 type).