1、Summary
Marsh funnel is an apparatus used to measure the viscosity of drilling fluids for daily. Adopting the API standard, determine the viscosity of drilling fluids with the time required for a given volume of drilling fluids pouring out from the funnel. The structure of the apparatus is simple. It is convenient for use and applied extensively in the departments dealing with petroleum and geological exploration.
2、Operation：
1)Block the flowing outlet of the funnel with finger, and then pour the drilling fluid sample into the clean and straight-upright funnel through screen until the surface of the fluid reaches the bottom of screen.
2)Put aside finger and at the same time start stopwatch, and then measure the time required for the drilling fluid flowing to the graduation mark of 946 ml (1qt.) in the sample cup.
3)Measure the temperature of the drilling fluid indicated by ℃ (or ℉) .
4)Record the Marsh funnel viscosity using second as the unit, and the temperature of the drilling fluid using ℃ (or ℉).
3、Check
1.The ambient temperature is controlled at 20±2℃, and stopwatch is in reserve.
2.Hold the funnel in an upright position, and use fingers to block the outlet of the lower end of the draft tube.
3.The distilled water 1500ml（20℃）was injected into the funnel.
4.Then release the fingers and start the timer. When the volume bottle enters 946ml, stop the time. The time should be 26±0.5s.
Note: before testing, all instruments must be rinsed clean.