What is Viscosity and How to Measure It?

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    What is Viscosity and How to Measure It

    What is Viscosity and Its Formula

    Viscosity is a significant criterion that allows for measuring the flow of fluids such as gasses, solids, and liquids. Viscosity relates to fluid thickness. The Viscosity results are obtained from the contact or difference between the molecules in a fluid. It is similar to the difference between moving solids when the viscosity will identify the energy that is needed to provide the flow of fluids.

    There are two types of viscosity: dynamic and kinematic.

    Dynamic viscosity is a strength that is essential for fluid to overtake its inner molecular friction thus making the fluid flow. Simply, dynamic viscosity is specified as the tangential strength per unit area that is needed to move the fluid in one horizontal plane with support to the other plane with a velocity unit while the fluid’s molecules maintain a unit distance apart

    Dynamic viscosity is also specified as the absolute viscosity in the fluid mechanic's sphere.

    Dynamic viscosity scheme

    Kinematic viscosity helps to measure fluid’s inner resistance that flows under the gravitational strengths. It is observed by measuring the time in seconds needed for an attached volume of fluid to flow a known distance by gravity through a capillary within a calibrated device at a closely controlled temperature.

    In physics, viscosity is often indicated as Isaac Newton’s comparison of fluids, which is comparable to Newton’s second law of motion. This law explains the action of the strength on an object, thus causing the object to speed up. The bigger the weight of the object, the more increased the strength will be essential to cause it to speed up.

    Viscosity Formula

    The viscosity formula is often explained by Isaac Newton’s comparison of fluids:

    F / A = n (dv / dr)*

    where F is strength and A is area. When strength is divided by area is the other way of determining viscosity. DV divided by dr shows the “shear rate”, or the moving speed of the liquid. The n is a constant gauging unit that is equal to 0.00089 Pa s, or as it is also explained as Pascal-second, which is a gauging unit for the dynamic viscosity. This law is helpful for different practical applications such as protein formulations or injections, and food and beverage manufacturings.

    Nowadays, a lot of manufacturers consider viscometers as a significant part of their observations, developments, and process control programs. They understand that viscosity gauging is often the most precise, durable, and quickest way to determine some of the most crucial aspects that impact a product’s performance.

    How Is Viscosity Measured?

    The viscosity of the solution is measured with a viscometer. The best viscometers are those that may be able to generate and control simple flow fields.

    The most common standard viscometers are constructed in a U-shape. Such a device is usually made of glass. The wider limb of the viscometer is placed on the side of the viscometer’s capillary tube and functions as the opening for the fluid that is needed to be measured is poured.

    The viscometer generally included two bulbs that are connected with a support of a U-shaped tube. One of these bulbs is attached to the capillary tube on one side and the rubber tube on the other side. The other bulb includes two etched markings on either side. These markings are maintained to monitor the limit of the flow of the liquids or solutions that pass through the capillary tube. In addition, these two markings are typically identified by upper Mark-A and lower mark-B. The other opening of the viscometer tube is connected to a rubber tube and is used to press the liquid inside.

    viscometer tube

    There are a lot of different ways to measure viscosity. Some of the most common ways are:

    The capillary viscometer is one of the oldest ways to measure viscosity. The capillary viscometer measures the time between the volume of the liquid that passes through the distance of the capillary tubes.

    A rotational viscometer measures the torque that is needed to rotate the object within the volume of the liquid.

    Falling Sphere Viscometer helps to measure the viscosity by decreasing the sphere of the specific mass and density and to measure the time that the sphere takes to achieve designated junctures.

    Zahn Cup Method allows measuring the viscosity by determining the time that the volume of the liquid takes to empty the cup that is placed in the bottom of the viscometer’s container.

    A vibrational viscometer measures the vibrational waves with the use of a vibrating rod that is submerged in the fluid. After that, the viscosity is measured by calculating the vibration dampening.

    Viscosity Chart

    Counting the viscosity of the fluids you need to measure may be puzzling and quite complicated. That is why we offer you a high-quality Viscosity Reference Chart that may help you to calculate the viscosity of the liquid effortlessly.

    In layman’s terms, the viscosity determines the fluid’s resistance flow. Simply, the higher the viscosity of the liquid or solution is, the thicker and the more increased the resistance flow. The temperature will influence the viscosity of most liquids and solutions.

    Fluid Specific Gravity Viscosity CPS Viscous Type
    Reference Water 1.0 1.0 Newtonian

    Adhesives

    "Box" Adhesives 1+- 3,000 Thixotropic
    PVA 1.3 100 Thixotropic
    Rubber & Solvents 1.0 15,000 Newtonian

    Bakery

    Batter 1.0 2.000 Thixotropic
    Butter (Melted) 0.98 18 @ 140 °F Newtonian
    Egg (Whole) 0.5 60 @ 50 °F Newtonian
    Emulsifier - 20 Thixotropic
    Frosting 1.0 10,000 Thixotropic
    Lectithin - 3,250 @ 125 °F Thixotropic
    77% Sweetened Condensed Milk 1.3 10,000 @ 77°F Newtonian
    Yeast Slurry 15% 1.0 180 Thixotropic

    Beer

    Beer 1.0 1.1 @ 40°F Newtonian
    Brewers Concentrated Yeast (80% solids) - 16,000 @ 40°F Thixotropic

    Confectionery

    Caramel 1.2 400 @ 140°F Thixotropic
    Chocolate 1.1 17,000 @ 120°F Thixotropic
    Fudge (Hot) 1.1 36,000 Thixotropic
    Toffee 1.2 87,000 Thixotropic

    Cosmetics/Soaps

    Face Cream - 10,000 Thixotropic
    Hair Gel 1.4 5,000 Thixotropic
    Shampoo - 5,000 Thixotropic
    Toothpaste - 20,000 Thixotropic
    Hand Cleaner - 2,000 Thixotropic

    Dairy

    Cottage Cheese 1.08 225 Thixotropic
    Cream 1.02 20 @ 40°F Newtonian
    Milk 1.03 1.2 @ 60°F Newtonian
    Process Cheese - 30,000 @ 160°F Thixotropic
    Yogurt - 1,100 Thixotropic
    Detergents Detergent Concentrate - 10 Newtonian

    Dyes & Inks

    Printers Ink 1 to 1.38 10,000 Thixotropic
    Dye 1.1 10 Newtonian
    Gum - 5,000 Thixotropic

    Fats & Oils

    Corn Oil 0.92 30 Newtonian
    Lard 0.96 60 @ 100°F Newtonian
    Linseed Oil 0.93 30 @ 100°F Newtonian
    Peanut Oil 0.92 42 @ 100°F Newtonian
    Soybean Oil 0.95 36 @ 100°F Newtonian
    Vegetable Oil 0.92 3 @ 300°F Newtonian

    Misc. Foods

    Black Bean Paste - 10,000 Thixotropic
    Cream Style Corn - 130 @ 190°F Thixotropic
    Catsup (Ketsup) 1.11 560 @ 145°F Thixotropic
    Pablum - 4,500 Thixotropic
    Pear Pulp - 4,000 @ 160°F Thixotropic
    Mashed Potato 1 20,000 Thixotropic
    Potato Skins & Caustic - 20,000 @ 100°F Thixotropic
    Prune Juice 1 60 @ 120°F Thixotropic
    Orange Juice Concentrate 1.1 5,000 @ 38°F Thixotropic
    Tapioca Pudding 0.7 1,000 @ 235°F Thixotropic
    Mayonnaise 1 5,000 @ 75°F Thixotropic
    33% Tomato Paste 1.14 7,000 Thixotropic
    Honey 1.5 1,500 @ 100°F Thixotropic

    Meat Products

    Melted Animal Fats 0.9 43 @ 100°F Newtonian
    Ground Beef Fats 0.9 11,000 @ 60°F Thixotropic
    Meat Emulsion 1 22,000 @ 40°F Thixotropic
    Pet Food 1 11,000 @ 40°F Thixotropic
    Pork Fat Slurry 1 650 @ 40°F Thixotropic
    Misc. Chemicals Glycols 1.1 35 @ Range -

    Paint

    Metallic Auto Paints - 220 Thixotropic
    Solvents 0.8 to 0.9 0.5 to 10 Newtonian
    Titanium Dioxide Slurry - 10,000 Thixotropic
    Varnish 1.06 140 @ 100°F -
    Turpentine 0.86 2 @ 60°F -

    Paper & Textile

    Black Liquor Tar - 2,000 @ 300°F -
    Paper Coating 35% - 400 -
    Sulfide 6% - 1,600 -
    Black Liquor 1.3 1,100 -
    Black Liquor Soap - 7,000 @ 122°F -

    Petroleum & Petroleum Products

    Asphalt (Unblended) 1.3 500 to 2,500 -
    Gasoline 0.7 0.8 @ 60°F Newtonian
    Kerosene 0.8 3 @ 68°F Newtonian
    Fuel Oil #6 0.9 660 @ 122°F Newtonian
    Auto Lube Oil SAE 40 0.9 200 @ 100°F Newtonian
    Auto Lube Oil SAE 90 0.9 320 @ 100°F Newtonian
    Propane 0.46 0.2 @ 100°F Newtonian
    Tars 1.2 Wide Range -

    Pharmaceuticals

    Castor Oil 0.96 350 Newtonian
    Cough Syrup 1 190 Newtonian
    Stomach" Remedy Slurries - 1,500 Thixotropic
    Pill Pastes - 5,000 +/- Thixotropic

    Plastic Resins

    Butadiene 0.94 0.17 @ 40°F -
    Polyester Resin (Typ) 1.4 3,000 Thixotropic
    PVA Resin (Typ) 1.3 65,000 -

    Starches & Gums

    Corn Starch Sol 22°B 1.18 32 Thixotropic
    Corn Starch Sol 25°B 1.21 300 Thixotropic

    Sugar, Syrups, Molasses

    Corn Syrup 41 Be 1.39 15,000 @ 60°F Newtonian
    Corn Syrup 45 Be 1.45 12,000 @ 130°F Newtonian
    Glucose 1.42 10,000 @ 100°F -
    Molasses A 1.42 280 to 5,000 @ 100°F -
    Molasses B 1.43 to 1.48 1,400 to 13,000 @ 100°F -
    Molasses C 1.46 to 1.49 2,600 to 5,000 @ 100°F -
    60 Brix 1.29 75 @ 60°F Newtonian
    68 Brix 1.34 360 @ 60°F Newtonian
    76 Brix 1.39 4,000 @ 60°F Newtonian
    Water & Waste Treatment Clarified Sewage Sludge 1.1 2,000 Range -

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