Orbis BV

TBR – Tannas Basic Rotary Viscometer

TBR – Tannas Basic Rotary Viscometer

High Temperature, Low Shear Rate Rotational (Absolute) Viscometer


A low-shear (1-200 reciprocal seconds) rotational viscometer that measures true viscosity (dynamic) not a combined viscosity-density value (kinematic). This is very important when distinguishing the viscous properties of synthetic and mineral oils or when comparing water-based and oil-based lubricants. For automotive applications the TBR has been found particularly useful in measuring the viscosity of sooted diesel engine oils.

The TBR maintains a constant shear rate from 1 to over 200 reciprocal seconds (sec-1), depending on speed setting and rotor size. The instrument analyzes fluids with viscosities ranging from 1 to 35,000 cP with the current Rotor design. For measuring higher viscosities, a different size Rotor may be required. This can be investigated and manufactured on a project-by-project basis, and the instrument can be customized to fit your needs. The desired operating temperatures would be required for such a project to commence.

When measuring oils with viscosities too high to manually (hand) inject into the TBR via the syringe, a Pump Controller is required.


Test type