Omnitek S-Flow IV+ Automatic Houillon Viscometry System



The kinematic viscosity characterizes flow behavior. This method covers the measurement of kinematic viscosity of transparent and opaque liquids; such as base oils, formulated oils, diesel oil, biodiesel blends, residual fuel oils, marine fuels, and used lubricating oils using an automated Houillon viscometer. 

  • Applicable for fuels, base oils, formulated oils, and petroleum products as well as water-based fluids
  • Compliant with requirements for ASTM D7279, ASTM D2240, and correlation to ASTM D445
  • High throughput: up to 80 samples per hour per bath under ideal operating conditions
  • Very easy to use and maintain
  • 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 calibration of the optic amplifiers
  • Automatic flow time measurement with ultraprecise meniscus detection
  • Fully automatic cleaning and drying
  • Fast and easy tube replacement (tubes are not connected to optical sensors)
  • No need to drain bath during tube replacement
  • Single or dual solvent injection (optional)
  • Measurement at 2 temperatures in 1 system simultaneously
  • Integrated VI calculations 
  • Stand-alone unit. No PC required. Software operation is available as an option
  • Chemically resistant to allow for all common solvents
  • Bath scheduler to turn baths on/off on preset times
  • Bath temperature graphs on screen
  • Bath backlight improves visibility of viscometer tubes and sensors
  • User assess control
  • Optional duplo measurement capability
  • Integrated back flushing
  • Optional software available
  • Optional autosampler

The S-flow IV+ instrument consists of compact, bench-top automated viscometry systems for the analysis of Newtonian fluids. It complies fully with ASTM D7279 and ASTM D2270, and gives full correlation with ASTM D445. It is the ideal system for used oil labs that need to test a wide range of lubricant viscosities. 

The latest generation of S-flow builds on the strong foundation of its pre-decessors to offer the ultimate in automatic viscometry testing of Newtonian samples, such as petroleum products. The system offers all the tried and tested advantages of a Houillon-type tube design, such as short process times, small sample volume and low solvent consumption, but now also includes an optional auto-sampler to allow for fully unattended operation. All controlled from a central software interface that takes care of result storage, auto-sampler control, calculations and much more. The new S-flow IV+ consists of 2 bath systems with 2 tubes in each bath, and it provides dual temperature measurements in an extremely compact package. Other options include dual solvent cleaning and integrated duplo testing, which obtains 2 flow time determinations with only 1 sample injection. 

Additional parameters such as tube constants and cleaning cycle are also controlled by the operator, because the sample volume is very low (0.3 - 1 mL), the entire measurement cycle is very short. Cycle time ranges between 3 to 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. 

All measurement parameters, such as warmup times and cleaning parameters, can be set through the high resolutions 12" touchscreen or with optional PC software. The diagnostic system alerts the operator to possible issues, such as empty solvent supply tanks, full waste bottles, insufficient vacuum, etc. The optional auto-sampler is fully modular and can be installed after market, meaning you can purchase the analyzer first and then upgrade to auto-sampling when the need arises. 


  • Viscometer Tubes
  • Starter Kit
  • Calibration Standards
  • Bath oil


Conforms to the specifications of: 

ASTM D7279, D2270

    Correlates to ASTM D445

Measuring Range: 0.3 - 3,000 mm2/s (cSt) @ 40 °C

Temperature Range: 20 to 120 °C (68 - 248 °F) (*For temperatures around ambient, and external chiller is required)    

Temperature Stability: Better than ±0.02 °C

Timer Accuracy: 0.001 s

Sample Volume: 0.3 - 1.0 mL

Solvent Consumption: 2 - 3 mL per cycle

Sample throughput: Up to 80 samples per hour per bath (under optimal conditions)

Number of Baths: 2 baths

Viscometers per Bath: 2 viscometer tubes per bath 

Viscometer Type: Houillon

Sensor Type: Optical, self-calibrating

Time Measurement: Automatic

Integrated Cleaning Pump: Yes

Solvent Injection: Automatic

Warmup Prior to Measuring: Yes

Touchscreen: 12" Capacitive

Data Export: USB storage device

115/240 V, 50/60 Hz, 950 kW

wxdxh,in.(cm)

15.75" x 22.85" x 26" (40 x 58 x 66 cm)

Net Weight
100 lb (45 kg)

  • Autosampler
  • Duplo measurement
  • Dual solvent injection
  • Positive-displacement pipette (for highly viscous samples)
  • External cooling system (for measurements around room temperature)
  • Air compressor (if no compressed air is available)
  • PC for instrument control
  • Advanced PC software
  • Silicone Oil