| Kinematic viscosity testing using the S-flow-1200 (page 1/2) |
Theory
The kinematic viscosity of a fluid equals its dynamic (or absolute) viscosity divided by its density. It is determined by measuring the time (in sec) required for a specified volume of liquid to flow by gravity, at a specified temperature, through a standard capillary tube (i.e. of known dimensions and volume). Kinematic viscosity is widely regarded as the most important parameter for oils and lubricants.
In practice, the measuring procedure for the S-flow-1200 is very straightforward and explained below. The depicted S-flow tube shows the different steps as well:
- take a sample...
- ... inject 0.3-0.5 ml at the top of the viscometer
- ... the sample will collect in the horizontal arm of the viscometer and warms up
- ... the sample flows into the capillary
- ... the sample passes the first optical sensor, the measurement begins
- ... the sample passes the second sensor, the measurement ends
- ... if a printer is present, the result is printed out, otherwise presented on-screen
- ... the system performs a user-defined cleaning and drying process
- The system is ready for the next sample...
Note : after step 2, operator attendance is no longer required : the system will perform the measurement automatically, print out or store the result and complete the cleaning cycle, readying itself for intake of the next sample. An entire measuring cycle (i.e. the time between 2 injections of sample) can be as short as 3 minutes, that's including cleaning !
Since the sample is injected from the top of the viscometer, it passes the optical sensor only once, thereby making it suitable for both transparant and opaque samples.
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