In economic terms, an error of one percent product viscosity that causes a blend adjustment can easily result in increasing product cost by a penny per gallon. There are many factors that affect the precision of this test method. It is determined by measuring the time it takes for a volume of fluid to flow under gravity through a calibrated glass capillary viscometer.Īlthough it sounds simple, achieving the high accuracy and precision required by the industry is an extremely formidable task. The term “kinematic” simply means that the measurement is made while fluid is flowing under the force of gravity.
The criticality of kinematic viscosity measurement prompted the petroleum industry to develop a precise method, first published in 1937, ASTM D445, Test Method for Kinematic Viscosity of Transparent and Opaque Liquids. Small changes in viscosity can have a dramatic impact on the properties of petroleum fluids. It is an important measurement characteristic in the food, paint, polymer coating and other industries where flow is a critical product or use characteristic. The viscosity of crude oil affects our ability to pump it out of the ground the viscosity and volatility of a fuel affects how easy it is to atomize in the fuel injector the viscosity of a lubricant affects its ability to protect an engine. It is one of the most important properties of a fluid and plays a prominent role in the petroleum industry. Ensure that they are well sealed so that liquid cannot escape.Viscosity is a measure of a fluid’s resistance to flow. Tape these together with a measured amount of liquid in the bottom cup. Water (you could colour this to be more similar in colour to the other liquids used)Ĭlear plastic cups.¼ of a small cup) of each liquid in plastic cups in preparation for the investigation. Ideally these will be similar in colour (eg yellow). Equipment listĪ selection of household liquids. They should understand that changing one variable (the independent variable) may have an effect on another (the dependent variable). They should be aware of what can be changed (the ‘variables’) and whether this might make a difference to the outcome. Learners should have been introduced to comparative or fair testing. They should understand that friction occurs when materials rub against each other to oppose motion.
Learners should know that force (a push or a pull) on an object can change its shape or movement. PDF | Editable Word document Classroom slidesĭOWNLOAD ALL What do learners need to know first? Set up and run the investigation with your class using the teacher notes and classroom slides, featuring a full equipment list, method, key words and definitions, questions for learners, FAQs and more.
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