Rotational Viscometers



Determines the dynamic viscosity of a substance by the rotation of a specified spindle within the sample at the speed giving the maximum torque reading on the viscometer. The resulting torque reading is used to calculate the viscosity of the substance.

Koehler offers 4 series of Rotational Viscometers

  • Digital Series
  • Advanced Digital Series
  • Programmable Series
  • Advanced Programmable Series

Digital & Advanced Digital

  • L Series: Viscosity Range: 1 to 2M cP (mPa·s)
  • R Series: Viscosity Range: 100 to 13M cP (mPa·s)
  • H Series: Viscosity Range: 800 to 104M cP (mPa·s)
  • For L, R, and H Series:
    • Speeds: 0.3 to 100 RPM
    • Number of Increments: 18

    Programmable & Advanced Programmable

  • L Series: Viscosity Range: 1 to 6M cP (mPa·s)
  • R Series: Viscosity Range: 100 to 40M cP (mPa·s)
  • H Series: Viscosity Range: 800 to 320M cP (mPa·s)
  • For L, R, and H Series:
    • Basic Speeds: 0.1 to 200 RPM
    • Advanced Speeds: 0.10 to 250 RPM
    • Basic Number of Increments: 200
    • Advanced Number of Increments: 2,600

    Key Features

    • No calculations required:
      • Direct reading of viscosity in cP or mPa·s
    • Displayed Information:
      • Viscosity (cP or mPa·s)
      • % Torque
      • Speed/Spindle
    • Easy to use:
      • Flip a switch
      • Turn a knob
    • Auto Range Button:
      • Push for determining full scale range (FSR) viscosity

    Ordering Information

    Part # Series Type Electrical
    K34750 Digital Rotational Viscometer Low Viscosity (L) 115V 60Hz
    K34751 Digital Rotational Viscometer Low Viscosity (L) 230V 50Hz
    K34752 Digital Rotational Viscometer Low Viscosity (L) 230V 60Hz
    K34753 Digital Rotational Viscometer Mid Viscosity (R) 115V 60Hz
    K34754 Digital Rotational Viscometer Mid Viscosity (R) 230V 50Hz
    K34755 Digital Rotational Viscometer Mid Viscosity (R) 230V 60Hz
    K34756 Digital Rotational Viscometer High Viscosity (H) 115V 60Hz
    K34757 Digital Rotational Viscometer High Viscosity (H) 230V 50Hz
    K34758 Digital Rotational Viscometer High Viscosity (H) 230V 60Hz

    Key Features

    • User Configuration Display:
      • User choice of most important parameter is displayed in larger font size
    • Choice of static or scrolling display mode
    • Displayed Information:
      • Viscosity (cP, P, mPa·s, or Pa·s)
      • % Torque
      • Speed/Spindle
      • Temperature (°C or °F)
      • *If RTD Temperature Probe is purchased
    • Choice of Multiple Languages:
      • English, French, German, Portuguese, Russian, Spanish
    • USB PC Interface for use with optional Software
    • Direct Access:
      • To time measurement function (time to torque, time to temperature, time to stop)
    • Automatic Range Calculation
      • Full Scale Range (FSR) at 100%
      • Maximum Viscosity measured with Spindle/Speed combination
      • Temperature Off-Set capability to ±5°C

    Ordering Information

    Part # Series Type Electrical
    K34740 Advanced Digital Rotational Viscometer Low Viscosity (L) 115V 60Hz
    K34741 Advanced Digital Rotational Viscometer Low Viscosity (L) 230V 50Hz
    K34742 Advanced Digital Rotational Viscometer Low Viscosity (L) 230V 60Hz
    K34743 Advanced Digital Rotational Viscometer Mid Viscosity (R) 115V 60Hz
    K34744 Advanced Digital Rotational Viscometer Mid Viscosity (R) 230V 50Hz
    K34745 Advanced Digital Rotational Viscometer Mid Viscosity (R) 230V 60Hz
    K34746 Advanced Digital Rotational Viscometer High Viscosity (H) 115V 60Hz
    K34747 Advanced Digital Rotational Viscometer High Viscosity (H) 230V 50Hz
    K34748 Advanced Digital Rotational Viscometer High Viscosity (H) 230V 60Hz

    Key Features

    • 5-Inch Full Color Touch Screen Display:
      • Simplified User Interface
      • Enhanced Controls
      • Real Time Trend Indicator
      • Supports Multiple Languages
    • Displayed Information:
      • Viscosity (cP or mPa·s)
      • Temperature (°C or °F)
      • Shear Rate/Stress
      • % Torque
      • Speed/Spindle
      • Step Program Status
    • Enhanced Security:
      • Customizable User Access, Date and Time Stamp File, Password Access, Portable Log-in Settings
    • Built-In Options:
      • Timed Tests, Data Averaging, Programmable QC Limits/Alarms, Customizable Speed/Spindle Lists, Test Based User Instructions, On Screen Data Comparison
    • Auto Range Showing
    • Maximum Viscosity measured with Spindle/Speed Combination
    • Download Custom Test Programs
    • Built-In RTD Temperature Probe
    • Convenient Bubble Level

    Ordering Information

    Part # Series Type Electrical
    K34760 Programmable Rotational Viscometer Low Viscosity (L) 115V 60Hz
    K34761 Programmable Rotational Viscometer Low Viscosity (L) 230V 50Hz
    K34762 Programmable Rotational Viscometer Low Viscosity (L) 230V 60Hz
    K34763 Programmable Rotational Viscometer Mid Viscosity (R) 115V 60Hz
    K34764 Programmable Rotational Viscometer Mid Viscosity (R) 230V 50Hz
    K34765 Programmable Rotational Viscometer Mid Viscosity (R) 230V 60Hz
    K34766 Programmable Rotational Viscometer High Viscosity (H) 115V 60Hz
    K34767 Programmable Rotational Viscometer High Viscosity (H) 230V 50Hz
    K34768 Programmable Rotational Viscometer High Viscosity (H) 230V 60Hz

    Key Features

    • 7-Inch Full Color Touch Screen Display
    • Real Time Graphing
    • Supports Multiple Languages
    • Displayed Information:
      • Viscosity (cP, P, mPa·s, or Pa·s)
    • Temperature (°C or °F)
    • Shear Rate/Stress
    • % Torque
    • Speed/Spindle
    • Step Program Status
    • Math Model Calculations
    • Built-In Math Models:
      • For Data Analysis in Stand-Alone Mode
    • Enhanced Security
    • Built-In Options:
      • Math Modeling, Temperature Control, Yield Tests, Programmable QC Limits/Alarms
    • Analyze Characteristics:
      • Such as Yield Stress, Flow Curves (mixing, pumping, spraying) Leveling and Recovery
    • Internal Data Storage: 150 MB
    • Stand-Alone Programming or Download Custom Tests
    • Built-In RTD Temperature Probe
    • Convenient Bubble Level

    Ordering Information

    Part # Series Type Electrical
    K34730 Advanced Programmable Rotational Viscometer Low Viscosity (L) 115V 60Hz
    K34731 Advanced Programmable Rotational Viscometer Low Viscosity (L) 230V 50Hz
    K34732 Advanced Programmable Rotational Viscometer Low Viscosity (L) 230V 60Hz
    K34733 Advanced Programmable Rotational Viscometer Mid Viscosity (R) 115V 60Hz
    K34734 Advanced Programmable Rotational Viscometer Mid Viscosity (R) 230V 50Hz
    K34735 Advanced Programmable Rotational Viscometer Mid Viscosity (R) 230V 60Hz
    K34736 Advanced Programmable Rotational Viscometer High Viscosity (H) 115V 60Hz
    K34737 Advanced Programmable Rotational Viscometer High Viscosity (H) 230V 50Hz
    K34738 Advanced Programmable Rotational Viscometer High Viscosity (H) 230V 60Hz