ISO Viscosity Cups

ISO Dip Cup Instructions

1. Adjust the temperature of the material to be measured if necessary. Lower the cup into the material so that the top rim is submerged. Place a thermometer into the cup as it is immersed and determine the temperature of the confined sample.
2. Remove thermometer. Hold cup vertically by inserting index finger into handle ring. In a quick, steady motion, lift the cup out of the sample material, starting the timer when the cup breaks the surface. During the flow time, hold the cup no more than 6” above the level of the sample material. Stop the timer when the first definite break in the stream at the base of the cup is observed.
3. Record the cup used such as 3mm Gardco/ISO Mini Dip Cup, the measured temperature and the efflux time. If the efflux time is immediately converted to Standard Gardco/ISO Cup time by multiplying by 2, it should be so noted. As an option to the preceding step, refer to the Viscosity Calculator App or conversion table for the cup to determine the centistoke viscosity for the measured efflux time in seconds and record this value and the measured temperature.
4. Promptly clean the cup with close attention to the orifice. (Use a length of nylon fishing line to clean the orifice.)

ISO Standard Cup Instructions

1. Select the proper cup/orifice combination to be used from the Specification Table, which is dependent on the expected viscosity range of the material to be measured.
2. Insure that the cup is clean and that there is no residual dried material in or around the orifice.
3. Insure that the test material is at specified measuring temperature.
4. Place the selected cup in a suitable leveled holder and place a receiving container under the cup.
5. Place a finger against the orifice and fill the cup until the meniscus where the liquid joins the sidewall of the cup disappears. If there are bubbles in the sample, allow time for them to rise to the surface. If overfilled, remove the excess by sliding the cover plate across the top of the cup. With the plate in this position, the finger may be removed. Remove the finger from the orifice or pull the scraper plate from the top at the cup and simultaneously start a timer.
6. Hold a thermometer in the efflux stream in order to accurately determine the temperature of the test material.
7. Stop the timer at the first observed break in the efflux stream between one and two inches below the orifice. Caution: There may not be a distinct break with the 8mm orifice. Instead, there may be a distinct change in the efflux stream as the flow shifts from a filled orifice to drainage from the cup sidewall. Stop the timer at the time of this distinct change. This distinct change is sometimes better observed looking down into the cup when testing clear materials.
8. Record the cup used, the designation and temperature of the test material and the number of seconds of efflux time. As an option to the preceding step, refer to the Viscosity Calculator App or conversion table for the cup to determine the centistoke viscosity for the measured efflux time in seconds and record this value and the measured temperature. (Example: GARDCO/ISO 4mm Cup, (test material), 25.1°C, 35.0 seconds)
9. Promptly clean the cup unless it will be used immediately for a rerun of the same material.