Marsh funnel viscometer MLN-4

laboratory

Marsh Funnel Viscometer GENERAL INFORMATION The Marsh Funnel Viscometer is a rugged, easy to operate instrument that is used for making rapid, on the spot measurements of drilling mud viscosity. The Marsh Funnel readings are only general measurements, but the frequent reporting of the Marsh Funnel Viscosity will alert the mud engineer to sudden changes in the mud viscosity that could require corrective action. The Marsh Funnel Viscosity is the ratio of the speed of the mud as it passes through the outlet tube (the Shear Rate) to the amount of force - the weight of the mud itself - that is causing the mud to flow (the Shear Stress). Marsh Funnel Viscosity is reported as the number of seconds required for one quart of mud to flow out of a full Marsh Funnel. MEASURING THE VISCOSITY OF DRILLING MUD NOTE A In addition to the Marsh Funnel, this procedure requires a container to collect a mud sample, a graduated container to receive the mud as it flows out of the funnel, some way to measure elapsed time (preferably a stop watch), and a centigrade or fahrenheit thermometer for measuring the temperature of the mud sample (See the Parts List). NOTE B The Marsh Funnel should be clean and dry before beginning this procedure. PROCEDURE 1. Collect a fresh mud sample. 2. Hold the funnel erect with a finger over the outlet tube, and pour the mud into the funnel through the screen until the mud level reaches the bottom of the screen (The screen will filter out the larger particles that could clog the outlet tube).