Viscosity Testing

Here are some things to consider when testing viscosity:

There are two different types of fluids - Newtonian and Non-Newtonian.

If you're lucky enough to have a Newtonian product (almost anything thin and watery, like milk or clear juices), you'll only have two things to consider:

• Temperature (changes in temperature affect the viscosity of any and every fluid, to varying degrees)
• Very low viscosity (might require a special instrument or adapter to get a reading)

• Plasticity (fluids that act like a solid when no force is being exerted on them, and require a certain amount of force to flow - think ketchup)
• Change over time (some fluids get thicker or thinner the longer a force is being exerted on them, and not all of them will return to their initial viscosity after the force stops - think whipping cream)
• Change with amount of force (some fluids get thicker or thinner when a greater amount of force is applied to them - think yogurt)
• Fluids can exhibit more than one, or indeed all of these behaviors.