Omnitek S-flow Kinematic Viscometer

Omnitek S-flow Kinematic Viscometer


S-flow Kinematic Viscometer

Manufacturer: OMNITEK

Product code: EA-5631-26

SKU: S-flow



The S-flow range of instruments consist of compact, bench-top automatic viscometry systems for the analysis of Newtonian fluids. It complies fully with in ASTM D7279 and as such, gives full correlation to ASTM D445. It is the ideal system for used oil analysis labs that need to test a wide range of lubricant viscosities.

“The S-flow system was designed for maximum throughput and ease of use while minimizing sample quantity and solvent consumption. It is the ideal viscometer for quick and accurate results”

Fast & accurate
The  S-flow  system  is  a  self-contained  viscometer  system that consists of a thermostatic bath with circular heater and a  control  column.  The  bath  contains  4  viscometer  tubes together with optical sensors to detect the fl ow of the sample through the tubes. All measuring tubes function independently of each other. The control column has an LCD display that provides the user with information about the system’s status  and  an  array  of  LED’s  indicate  the  current  status of  each  measuring  tube.  Although  a  PC  is  not  required  to operate the instrument, additional software is available for operationg and data storage and reporting.

High capacity
The entire cycle time ranges between 3-10 minutes per tube, allowing a throughput of up to 80 tests per hour. After  the  injection  of  the  sample,  operator  presence  is  no longer  required.  The  operator  needs  only  to  return  after the system has completed the measurement and cleaned the tube.



Version S-flow 400 L S-flow 850 S-flow 1200 S-flow 3000
Number of baths 1 1 1 2
Viscometers per system 4 4 4 8
Time measurement Manual Automatic Automatic Automatic
Cleaning pump No Yes Yes Yes
Chemically resistant Yes Yes Yes Yes
Solvent injection Manual Manual Automatic Automatic
Software available No Yes Yes Yes
Viscosity Index No No No Yes
Dual solvent option No No Yes Yes
Duplo measurement option No No Yes Yes
Samples per hour *) 20 – 40 25 – 40 40 – 80 80 – 160
Temperature range (°C) 20 – 150 20 – 110 20 – 110 20 – 110
Robotic operation prepared No No Yes Yes


S-flow 400L S-flow 850 / 1200 S-flow 3000


Optional accessories & upgrades

Dual solvent cleaning

A suitable solvent used for cleaning should have the following two main characteristics:
– It should be able to dissolve the sample that was tested, i.e. clean the tube
– It should evaporate quickly enough at the test temperature so that the tube is dry after cleaning
If the solvent used does have the ability to dissolve the sample, but does not evaporate quickly enough, a second solvent can be used to clean out the first solvent, as well as dry the tube. Usually, low boiling solvents are used for this purpose, such as Acetone or MEK. All fittings and valves on the system are fully chemically resistant and allow for the use of Acetone and MEK.

Cooling spiral & external chiller

For measurements close to ambient (± 30 °C), an additional external chiller is required to create sufficient offset for the temperature control unit. Each bath needs to be fitted with a cooling spiral, to which an external circulation chiller can be easily connected. Complete with tubing and fittings. Cooling spiral and external chiller will be supplied separately on request.  


Omnitek S-flow systems operate on clean 5-6 bar compressed air. Suitable compressor can be supply from Omnitek if no compressed air is available.


‘Easy-flow’ viscometers
For high viscosity fluids that need to be heated quickly, ‘Easy-flow’ viscometers can be great use.

‘Easy-flow’ viscometers are equipped with a large entrance zone which is positioned below oil bath level. Any injected fluid will get immediate contact with with hot glass area and will heat-up quickly.

‘Easy-flow’ viscometers can be provided starting from tube constant 1.0 ( > 30 cSt).

Duplo measurement upgrade

The optional duplo measurement upgrade adds another array of optical fibers to the instrument, bringing the total number of detection points to three per tube instead of two.  Together with adapted S-flow tubes, which are fitted with two measuring trajectories, this enables the S-flow 1200 and the S-flow 3000 VI to perform two time measurements with a single sample injection, increasing productivity, saving even more on solvent consumption and giving instant insight in test repeatability.



All Omnitek S-flow systems can be operated directly from the keypad interface, and both calibration and viscosity measurements can be performed without PC or software. However, to have more control, dedicated software is available, which can be used to control up to 4 individual systems. Several system settings can be monitored per system, such as:

  • Tube ID / Tube constant
  • Minimum / maximum flow time per tube
  • Reference viscosity in case of calibrations
  • Required filling volume
  • Allowed spread between consecutive samples
  • Yes / No real-time Viscosity Index calculation (only on S-flow 3000 VI)
  • Cleaning and drying settings
    • Draining time of solvent
    • Number of individual solvent injections
    • Duration of 1 solvent injection
    • Time between solvent injections
    • Drying time

For every tube / measurement information is given, such as:

  • Measurement stage (e.g. Measuring, Calibrating, Cleaning, Drying, etc)
  • Registered flow-time per measurement
  • Maximum / minimum flow-time per sample
  • Average flow-time and result (viscosity or calibration constant)
  • Depending on pre-set spread measurements can be excluded from calculations and automatically a new measurement can be started instead


Robotic operation

Omnitek offers “Robotic Operation” for models S-flow 1200 and 3000 VI for customers that run large numbers of samples (>500 samples per day) and want to automate their sampling process. As each laboratory will have its own requirements, automation is a highly customized products which requires elaborate preparation. Please contact us for specific solutions to your sampling needs .

Automatic robot operation   Detail robot operated injection



  • Applicable for fuels, base oils, formulated oils, and other petrochemical fluid chemicals as well as water based fluids
  • Compliant with requirements for ASTM D7279 and related specifications.
  • Very easy to use
  • Small sample volume : 0.3-1.0 ml
  • Low solvent consumption : 2-3 ml per sample
  • Extremely accurate temperature control and flow-time measurement independent of fluid type
  • Automatic flow time measurement with ultraprecise meniscus detection
  • Fully automatic cleaning and drying (model dependent)
  • Fast & easy tube replacement (tubes are not connected to optical sensors)
  • No need to drain bath during tube replacement
  • Single or dual solvent injection (model dependent)
  • Stand-alone unit. No PC required. Software operation is available as an option.
  • Chemically resistant to allow for all common solvents
  • Optional duplo measurement capability
  • Back Flush Kit

Test methods

This product is compliant with the following test methods:

  • ASTM D445
  • ASTM D7279
  • ASTM D2270
  • Condition Monitoring
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