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Viscosity Glossary

Viscosity & Rheology Glossary
 

Technical Terms, Standards, Instrument Components & Conversion References

Glossary Terms

 

3A

A U.S. industrial standard for process equipment design, often required for Clean-in-Place (CIP) certification.

Absolute Viscosity

Viscosity value associated with a Newtonian material.

ASTM

American Society for Testing and Materials. A U.S. organization responsible for establishing test standards.

Autorange

Feature that displays the maximum viscosity measurable with a selected spindle and RPM.

Bob

Spindle used with the PVS Rheometer. Remains stationary while the sample cup rotates.

Centipoise (cP)

A cgs unit of viscosity measurement.

Comm Port

Communication channel through which data is transmitted between devices.

Concentric Cylinder

A cylindrical spindle rotating inside a cylindrical chamber sharing the same centerline.

Cone Spindle

A spindle with a nearly flat circular surface positioned at a small angle to the plate.

CP / C-P

Brookfield terminology for cone and plate geometry.

Cylindrical Spindle

A spindle shaped like a cylinder.

Disc Spindle

A spindle featuring a flat circular disc used for viscosity measurements.

DIN

German standards organization responsible for establishing testing standards.

Dyne-cm

A unit used for torque measurement.

Fluid Ounce

Scientific unit of volume abbreviated as oz.

Footprint

The physical bench space occupied by equipment.

Gap

The distance between a spindle and the chamber or cup wall.

Guard Leg

Protective spindle bracket supplied with many Brookfield instruments.

HA

Torque range for medium-to-high viscosity materials. 100% torque = 14,374 dyne-cm.

HB

Torque range for high viscosity materials. 100% torque = 57,496 dyne-cm.

5xHB

Very high viscosity torque range. 100% torque = 287,480 dyne-cm.

Hz

Frequency unit expressed as Hertz or cycles per second.

In-line

Placement of a process viscometer directly in a pipeline.

KREBS Unit

Viscosity unit obtained using a KREBS spindle at 200 RPM.

LCD

Liquid Crystal Display.

LV

Torque range for low viscosity materials. 100% torque = 673.7 dyne-cm.

mA

Milliamp, a unit of electrical current.

Micro Liter (µL)

A very small unit of volume measurement.

mPa·s

Millipascal-second, a unit of viscosity measurement.

NIST

National Institute of Standards and Technology.

Newtonian

Material whose viscosity remains constant regardless of shear rate.

Non-Newtonian

Material whose viscosity changes with shear rate.

On-line

Continuous viscosity measurement during manufacturing processes.

pH

Measurement of acidity or alkalinity.

Pint

Volume measurement abbreviated as pt.

Plate Spindle

Flat circular spindle used for visco-elastic and particulate-containing materials.

Pneumatic

Operated by compressed air pressure.

Poise (P)

Unit of viscosity measurement.

PP

Brookfield terminology for plate and plate geometry.

Relative Viscosity

Viscosity of a Non-Newtonian material measured at a specified shear rate.

Rheology

The science of material deformation and flow.

Rheometer

An instrument used to measure flow behavior of materials.

RPM

Rotations Per Minute; spindle speed measurement.

RS-232

Data communication protocol used in computer systems.

RTD

Resistance Temperature Detector used for temperature sensing.

RV

Torque range for medium viscosity materials. 100% torque = 7,187 dyne-cm.

sec⁻¹

Scientific unit of shear rate measurement.

Shear Rate

Velocity gradient in a flowing material.

Shear Stress

Force per unit area required to move a material.

Spindle Geometry

The shape of a spindle such as disc, cone, cylinder, plate, or KREBS.

Time to Stop

Brookfield procedure measuring viscosity after a specified time interval.

Time to Torque

Procedure measuring the time required to reach a specified torque value.

Torque Range

Measurement capability of a viscometer expressed in dyne-cm.

Torque %

Amount of torque resistance measured by a rotating spindle.

Volt (V)

Unit of electrical potential.

Viscosity

Resistance of a material to flow. Viscosity = Shear Stress / Shear Rate.

Viscosity Range

Operating viscosity range achievable using selected spindles.

Yield Stress

Minimum force required to initiate material flow.

📐 Conversion Tables

Viscosity

1 cP=1 mPa·s
1 P=100 cP
1 Pa·s=1000 mPa·s

Sample Volume

1 L=1000 mL
1 gal=3.7 L
1 pt=16 oz

Torque Range

LV=673.7
RV=7,187
HA=14,374
HB=57,496
5xHB=287,480

Temperature

°C = 5/9 × (°F − 32)