Abstract: A testing apparatus comprising a chamber having an inlet and an outlet (16); a measuring device, at least a part of which is provided within the chamber; where the inlet is arranged to direct fluid onto the part of the measuring device within the chamber in order to clean the measuring device during start up. Thus the density or viscosity of drilling mud may be continuously monitored. Some exemplary embodiments include an outlet valve such as a ball valve with a bore defined therein. The bore allows fluid to flow therethrough even in a valve “closed” position and generates the preferred back pressure whilst minimizing the risk that the valve will block. A pressure activated drain valve may also be provided to substantially empty the chamber when not in use.

Abstract: The present invention relates to an apparatus (100) suitable for use in substantially continuous measurement of a physical property particularly the rheology and/or viscosity of a drilling fluid in use thereof in a drilling fluid or mud flow circuit of a drilling device. The present invention also relates to an apparatus (100) suitable for use in substantially continuous measurement of a physical property particularly the rheology and/or viscosity of any non-newtonian fluid is use thereof. The apparatus (100) comprises of a sample chamber (26) having an inlet (7) and an outlet (9) and is arranged to allow a drilling fluid to flow therethrough from the inlet 7 to the outlet (9). Detector devices (33, 34, 35) such as Viscometers are provided for substantially continuous measurement of a physical property particularly the rheology and/or viscosity of a drilling fluid flowing thought the sample chamber (26) in use of the apparatus (100).

Abstract: A testing apparatus comprising: a chamber (5) having an inlet (6) and an outlet (16); a measuring device (4), at least a part of which is provided within said chamber; wherein the inlet is arranged to direct fluid onto said part of the measuring device within the chamber in order to clean the measuring device during start up. Thus the density or viscosity of drilling mud may be continuously monitored. Preferred embodiments include an outlet valve such as a ball valve (7) with a bore defined therein. The bore allows fluid to flow therethrough even in a valve “closed” position and so generates the preferred back pressure whilst minimising the risk that the valve will block. A pressure activated drain valve (9) is also provided to substantially empty the chamber when not in use. When the apparatus is reactivated, an inlet tube is adapted to jet air and then fluid at the measuring device in order to remove debris therefrom. Thus the apparatus has the important benefit of self cleaning during start-up.

Abstract: A plurality of novel depth of cut scales are eccentrically inscribed on faces of circular cutting blades. The depth of cut marks on the scales are line segments that are easily lined up with the sole of a hand held circular saw, with the table of a table saw, or with the workpiece surface of a radial arm saw or a sliding miter saw. The accuracy of setting the depth of cut is greatly improved by the novel construct of the scales, which provides depth of cut index marks that are separated from each other by a distance larger than the difference between the indicated depths. The circular cutting blades with the novel depth of cut scales can be used in any cutting tool utilizing circular cutting blades without any modifications and without any additional external tools or instruments. The scales provided by present invention resolve to as small a distance as 1/32 of an inch on English units scales or to 0.5 mm on SI units scales.