Funnel viscometer is a simple equipment for measuring viscosity daily, used to determine the relative viscosity of drilling fluid (compare with water). Due to the measured data are largely affected by colloid ratio and proportion, it cannot be compared directly with the data measured by rotational viscometer, static shear force and rheometer.

The instrument is mainly composed of filter screen, funnel, measuring cylinder, etc. It has the feature of simple structure, convenient use and accurate measurement.

The measuring principle of funnel viscometer is that, the viscosity of drilling fluid is expressed by the time when quantitative drilling fluid freely flows out of a fixed funnel under the action of gravity.