Manual
4
4
Operation
4.1
Preparing the measurement
To perform a measurement, you need a stopwatch.
Also, please mind the following notes to prepare the measurement:
Make sure that the cup and the nozzle are clean and free from residues.
The liquid to be measured has to be homogeneous and free from air bubbles. Do not let the
sample rest for too long. The sample should be freshly strained (e. g. by stirring) before starting
the measurement.
Allow some time for the fluid and the cup for temperature compensation.
Measure and note down the temperature of the liquid.
You can only measure Newtonian fluids with the flow cup. To check if the sample is Newtonian,
observe the measuring procedure (see chapter 4.2) and follow these steps:
o
Fill the cup and measure the flow time immediately.
o
Fill the cup again and wait one minute before measuring the flow time.
o
If the deviation between both results is above 10 %, the sample is a non-Newtonian fluid.
In this case, you cannot measure it with the flow cup.
4.2
Taking a measurement
1. Place the cup in a way that the nozzle is aligned vertically and not blocked.
2. Place a finger on the nozzle to cover it.
3. Fill the cup to the brim. Pour the fluid into the cup gently to prevent the formation of air bubbles.
4. Slide the glass plate over the rim of the cup until it is covered completely. Excess sample is
absorbed by the overflow gutter.
5. Remove your finger from the nozzle and wait a while to allow air bubbles to get to the surface.
6. Remove the glass plate and start the flow time measurement at the same time.
7. Watch the fluid coming out of the nozzle. Once the flow breaks, stop the flow time measurement.
8. Repeat the measurement.
9. If the results of both measurements do not deviate by more than 5 %, calculate the average and
note it down.
10. After that, you can calculate the viscosity by using a viscosity nomogram, for example.
4.3
Maintenance
The flow cups of the PCE-128 series are low-maintenance devices.
If you need to perform calibration checks on a regular basis (e. g. in line with a quality management
system) we offer a variety of calibration oils.
