What should be paid attention to when doing viscosity Test

What should be paid attention to when doing viscosity test

1. When the viscosity is measured, the test temperature is different, and the constant temperature time is also different:

When measuring viscosity, the test temperature is different, and the constant temperature time of the viscometer in the constant temperature bath is also different. For example: the test temperature is 20℃ and the constant temperature time is 10 minutes; when the test temperature is 40℃ and 50℃, the constant temperature time is 15 minutes; the test temperature is 100℃, The constant temperature time is 20 minutes. This is because the greater the temperature difference with the indoor temperature, the longer it takes to reach the constant temperature. When measuring the viscosity, strictly following the specified constant temperature is one of the important factors to ensure the accuracy of the measurement results. Even the slightest temperature fluctuation (more than ±0.1°C) will cause large deviations in the viscosity measurement results. Therefore, in the viscosity measurement, the constant temperature must be strictly in accordance with the specified time.

2. The sample for measuring the viscosity must first be dehydrated and filtered of mechanical impurities

The test oil for measuring viscosity must be dehydrated first, and then filtered with filter paper to remove mechanical impurities. This is because the presence of water not only occupies the volume of the test oil, but also has a low viscosity and high density. It will vaporize at a higher measuring temperature. It condenses at low temperature, which affects the normal flow of liquid petroleum products in the viscometer, and makes the measurement result low or high. However, even a small amount of mechanical impurities mixed into the test oil will adhere to the inner wall of the capillary to hinder the normal flow of the liquid, increase the flow time, make the measurement result higher, and block the capillary in serious cases, affect the viscosity measurement, and make the parallel measurement results not repeated, so it must Dehydrate and filter.