#Viscosity chemistry means verification#To perform a valid verification check and confirm that the material is within specification requires a duplication of the test method used by the manufacturer. Data sheets for some polymer solutions, for example, may include a discrete number like 4,500 centipoise (cP), but no further information about how the measurement was made, not even the test temperature at which the polymer was measured. Raw materials in the chemical process industries (CPI) usually have a reported viscosity value on the data sheet that accompanies the product. Experiments have shown that the viscosity values obtained at 0.1 or 0.01 rpm can be several orders of magnitude higher than the one recorded at 20 rpm. When pumping asphalt, the startup torque required to get the pump going initially suggests that a second viscosity test at a much lower rotational speed makes sense. However, this straightforward single-point test does not provide the complete picture for asphalt flow behavior. Record the viscosity value, make sure that it falls within prescribed maximum and minimum limits, and then report whether the number passes or fails. The standard test method for pumpability, according to ASTM D4402, is to use a regular viscosity (RV) torque rotational viscometer at 20 rpm or a low viscosity (LV) instrument at 12 rpm. An important concept, sometimes forgotten, is that a material’s viscosity is not a single-point measurement, but often depends on a number of factors. This article reacquaints the reader with the basic concepts and terminology for viscosity and addresses techniques to quantify it. The bottom line is to come up with ways to measure viscosity so that you can quantify whether a material will flow the way it needs to. For handlers of all materials that flow, either while being processed or in an end-use, it is important to think about the materials’ flow characteristics. To be brief, viscosity is resistance to flow. Therefore, we’ve shown that corn syrup and honey have a higher viscosity (or are more viscous) than water and cooking oil.Most engineers know what viscosity is, but may have trouble explaining it. In our experiment, the marbles took longer to sink when dropped into the jars filled with corn syrup and honey than they did when dropped into the jars filled with water and cooking oil. The more viscous (or thick) a liquid is, the longer it will take for an object to move through the liquid. Viscosity can also be thought of as a measure of how “thick” a liquid is. Liquids that have a HIGH viscosity flow slowly (ie. water, rubbing alcohol, and vegetable oil). Liquids that have a LOW viscosity flow quickly (ie. Viscosity depends on the size and shape of the particles that make the liquid, as well as the attraction between the particles. Viscosity is a liquid’s resistance to flowing. The question answered in this experiment is: how does the consistency of a liquid impact how long it will take for a marble to sink in a jar of that liquid? A unique property of liquids is something called viscosity. Watch the Viscosity of Liquids Science Experiment Step by Step Instructions How Does the Science Experiment Work? Viscosity of Liquids Science Experiment Video Tutorial It also contains ideas on how you can expand on the experiment. Was your hypothesis correct? Do you know why some marbles sink to the bottom of the jar quickly and some marbles sink to the bottle of the jar slowly?įind out the answer in the how does this experiment work section below. You’ll notice right away that the marble behaves differently in each jar. Drop one marble at a time and observe what happens to the marble when it enters the liquid. Step 2 – Carefully drop one marble into each jar.
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