Engler viscometer is used for measuring the viscosity of lubricating oils. The first prototype of Engler viscometer is probably the unit constructed by Lomonosov in 1752. It measured the viscosity of liquids by the number of drops. This idea was the basis for the Engler viscometer.
The device consists of an oil cup with a spherical bottom. In its center there is an oil tube with a plug at the top. On the inner surface of the oil cup there are three marks. The liquid is poured up to the 200 cm3 mark.
Viscous fluids can be influenced by ambient temperature. To compensate, the cup is surrounded with a thermostat with a thermometer.
Engler viscosity is expressed in Engler degrees and is determined by a special formula: calculating the ratio of time of outflow of 50 ml of liquid at 20 ° C to the time of outflow of the same volume of distilled water at 25 °C. The kinematic viscosity is calculated on the basis of the empirical equation obtained previously.