417 Rigo's Zahn Viscosity Cup

Overview

The Model 417 Rigo's Zahn Viscosity Cup is the simplest type of comparative viscometer used to measure the viscosity of inks, paints, lacquers, and similar materials. It consists of a 40 mL capacity stainless-steel cup with an orifice in its base, fitted with a handle approximately 300 mm long. The test is carried out by timing how long it takes the sample to flow out through the orifice in the bottom of the cup, and this efflux time is then used to compare the viscosity of different samples. The cup is available in a range of orifice sizes, from No.2 through No.7, so that samples covering different viscosity levels can be tested with the same simple method.

Construction

The Zahn cup is machined from stainless steel as a single cup body of 40 mL capacity with a precisely sized orifice at its base. A handle roughly 300 mm long is attached to the cup so that it can be dipped into and withdrawn from the sample cleanly and held steady while the sample drains.

Test Method

The cup is filled by full immersion in the sample and then withdrawn while a timer is started; the operator records the efflux time as the stream of liquid draining from the orifice first breaks. This efflux time is a simple, direct indicator of the sample's viscosity and can be compared between batches or against a reference value.

Available Sizes

Because a single orifice size can only cover a limited viscosity range, the Model 417 cup is offered in orifice sizes No.2 through No.7, allowing the same portable, low-cost method to be applied across inks, paints, and lacquers of widely different viscosities.

Common Specifications

Model Comparison