Abstract: An apparatus for ascertaining the alcohol content or the calorific value of a mixture containing alcohol and gasoline includes an electrically conductive housing through which the mixture flows and in which at least one physical parameter of the mixture is measured to produce a measurement. An electronic measuring circuit is disposed in the housing for evaluating the measurement. The housing has a wall with a part of the wall forming a first electrode of a capacitor. An intermediate plate is associated with the housing. An electrically conductive sensor element is secured in the intermediate plate and partly surrounded by the mixture. The electrically conductive sensor element forms a second electrode of the capacitor and forms an electrical connection between the second electrode and the measuring circuit.

Abstract: Quantification of blood plasma fibrinogen content is made in a sample of anticoagulated whole blood contained in a sampling tube. The tube is a transparent centrifuge tube which contains a sample constituent layer-elongating float. The blood sample is centrifuged in the tube containing the float, and various cell constituent measurements are made. The centrifuged sample is then heated and recentrifuged to cause the precipitated fibrinogen to layer out on top of the float remote from the buffy coat band in the plasma layer. The thickness of the fibrinogen band is then measured, whereby quantification of the fibrinogen content of the blood sample can be made by a precalibrated instrument.

Abstract: A method for locating and identifying defects in a variable geometry workpiece using first and second transceivers positioned of a preselected distance apart adjacent opposite surfaces of the workpiece and aligned to direct ultrasonic signals toward each other through the workpiece. An ultrasound signal is transmitted from each transceiver toward the workpiece. Signal reflections from each adjacent workpiece surface are detected and used to compute workpiece thickness. Signals from one transceiver are detected at the other transceiver and their intensity determined. The signal intensity is normalized in proportion to the obtained workpiece thickness to establish a signal intensity independent of workpiece thickness. In one form, at least three signal processing paths, each having a different preselected gain, provide three signals of different amplified intensities for each measurement point.

Abstract: A test cell utilizing a pressure vessel having a vertically oriented filter having 7 square inches of flow area located therein with the vessel being sufficiently deep to provide a settling chamber below the filter for weighting materials which settle out in the presence of the high temperatures. The methods presented herein provide a means for testing polymer drilling muds that yield consistent and repeatable results that can be correlated to fluid loss indices of other drilling muds. The methods involve filling the vessel with polymer mud, heating the mud to the predetermined temperature, applying pressure to the drilling mud to force it through a 7 square inch flow area filter and measuring the filtrate over a predetermined period of time to establish the flow index.

Abstract: A method and apparatus for analyzing sag phenomena in well fluids wherein an elongate container containing a sample of a fluid to be tested is mounted at an angle with respect to vertical on a force responsive device which provides a measurable, variable indication of the center of mass of the container. The angle is chosen to correspond to that of a well deviation angle for which testing is to be done, and the sample may be subjected to heat and pressure to further simulate downhole conditions. The aforementioned indication provided by the force responsive device is repeatedly measured and functionally related to time.

Abstract: A gas measuring and warning device includes a test tube which is traversed by the gas to be detected and with a photoelectric sampling means which contains an imaging optical system by which the test tube reaction image is projected onto the photo-sensitive row of the sensor elements. The imaging optical system contains a cylindrical lens having a cylinder axis which is parallel to the longitudinal axis of the test tube and to a row of sensor elements. Advantageously an achromatic lens as well as of an interference filter and of a pulse light source as used.

Abstract: Cold start performances in an engine of a wax-containing fuel may be assessed by drawing said fuel from a container under standardized conditions through a filter and measuring the rate of flow of fuel past said filter and comparing said flow rate with a flow rate obtained under the same conditions with a fuel of known cold start performance. This provides a relatively quick and simple indication of whether an engine running on such a fuel at the test temperature might be expected to have its filter blocked by the wax, preventing it from starting.

Abstract: A method and an apparatus for the automatic determination of the dry pulp content, the infiltration capacity and the wire retention of a pulp suspension. In the method the automatically or manually taken pulp suspension sample is brought to the sample container (2) of the determination equipment (1) located in the immediate neighborhood of the production or the operation process. According to the invention the quantity of the sample in the sample container is measured by weighing, the sample is in case of need attenuated into the processing consistency range, a part of the sample is led to the filter (4), is filtrated in the filter with and/or without a filtering paper, the sample cake obtained is transferred to the desiccator (8) and dried with the desiccator, the dried sample cake is weighed and the test results are written out with the output equipment (11).

Abstract: A method of performing measurement of a hematocrit value and separate sampling of plasma and blood cells, simultaneously. A probe including a pair of detection electrodes each in the form of a suction nozzle, is lowered from a certain initial height into a sample vessel containing blood that has bveen separated into an upper plasma layer and a lower blood cell layer, while the probe travel distance is monitored. When the detection electrodes touch the surface of the plasma layer, the plasma is sampled into a corresponding sampling vessel through one of the electrode suction nozzles. The probe is then lowered further until the electrodes touch the surface of the blood cell layer, and the blood cells are sampled into a different sampling vessel through the other one of the suction nozzles.

Abstract: An apparatus for processing and analyzing blood serum includes an input rack for holding test tubes containing whole blood specimens and separator gel, a centrifuge, an optical sensing unit for receiving centrifuged test tubes and generating output signals indicative of whether the centrifuging was successful and, if it was, the boundary position between the separator gel and the blood serum, and a computer connected to receive and analyze the output signals of the optical sensing unit. An aspirator/dispenser needle unit is positioned above the sensing unit and is capable of lowering a needle, under the control of the computer, to puncture the stopper of a test tube and then withdraw blood serum.

Abstract: This invention is a semiautomatic hematocrit reader apparatus and method. A microhematocrit capillary tube is positioned under a movable cursor which is then moved along the length of the microhematocrit capillary tube. A switch is depressed to make a data entry at predetermined points along the length of a blood/plasma sample in the microhematocrit capillary tube. The relative distances travelled across the packed cell volume versus the plasma is electronically calculated and displayed automatically.

Abstract: A whole blood sample is placed in a tube such as a capillary tube, with a plastic float. The float is axially elongated and has a specific gravity which causes it to float in the packed red blood cells when the sample is centrifuged in the tube. The hemoglobin concentration of the packed red blood cells is measured by measuring the depth that the float sinks into the red cell layer, and then the hemoglobin concentration of the blood is calculated. The hemoglobin can be measured in this manner because virtually the only red cell component which contributes density to the red cells is the hemoglobin. The hemoglobin concentration of the whole blood is calculated by multiplying the mean corpuscular hemoglobin concentration of the packed red blood cells by the packed cell volume % (hematocrit) of the whole blood. All of the necessary calculations may be performed by a preprogrammed microprocessor.

Abstract: An ultrasonic inspection system for composite materials capable of detecting flaws near the surface of the inspected part which flaws are normally masked by strong reflections from the part surface. An electronic signal representative of the strong surface echo is stored in memory and subtracted in a differential amplifier from the entire test piece echo representative signal in time relationship which effects cancellation of the signal representative of the strong surface echo thereby allowing weaker echo representative signals from defects near the surface to the detected.

Abstract: A process for particle size distribution analysis of a particulate substance of particle size in the range of 0.05 to 50 microns, which comprises a photosedimentation method using a horizontal rotating disc centrifuge and a narrow band of a dispersion of the particulate substance in juxtaposition to a column of clear sedimentation liquid.

Abstract: An automatic monitoring and recording device for erythrocyte sedimentation employs a light source and a photodetector to detect the changes of light transmittance at the junction of plasma and red blood cell column. Changes of light transmittance at the junction reflect the descent of red blood cell column. The light source and photodetector pair is arranged so that it will track to the plasma - red blood cell column junction all the way the red blood cells fall. The whole course of erythroctye sedimentation is monitored and recorded automatically by a microcomputer.

Abstract: A whole blood sample is placed in a tube such as a capillary tube, with a plastic float. The float is axially elongated and has a specific gravity which causes it to float in the packed red blood cells when the sample is centrifuged in the tube. The hemoglobin concentration of the packed red blood cells is measured by measuring the depth that the float sinks into the red cell layer, and then the hemoglobin concentration of the blood is calculated. The hemoglobin can be measured in this manner because virtually the only red cell component which contributes density to the red cells is the hemoglobin. The hemoglobin concentration of the whole blood is calculated by multiplying the mean corpuscular hemoglobin concentration of the packed red blood cells by the packed cell volume % (hematocrit) of the whole blood. All of the necessary calculations may be performed by a preprogramed microprocessor.

Abstract: An apparatus and method for testing the performance of spotting fluids used for freeing drill pipe stuck to drilling mud filter cake in a borehole. A small cylinder simulating the drill pipe is pressed against a filter cake in a vessel. Spotting fluid is applied and the cylinder and cake are pulled apart. The maximum force required to free the cylinder is recorded.

Abstract: Method for the digital peak value measurement for ultrasonic test pulses having a predetermined pulse repetition frequency. After amplification, the input signal to be measured is present at a comparator circuit the output of which is connected, within a predetermined time slot, periodically generated, for the expected signal time range, to a memory which is reset at the beginning of the time slot. The received signal is applied to a window comparator the window width of which corresponds to one voltage step of a reference voltage which is supplied by a D/A converter and which can be changed in steps. The D/A converter is controlled by a digital counter the direction of counting of which is controlled in dependence on the memory contents and which is stopped in the case of equality between the received signal within the time slot and the respective reference voltage. The display is derived from the final count.

Abstract: A pressure vessel comprises a cylindrical container with a closed end, externally threaded at an open end, and having an O-ring seal in the end surface of the container side wall. A cylindrical disk closes the open end of the container and has a raised neck portion surrounded by a recessed cavity having a rupture disk therein. An internally threaded cap memeber has a hole through its end wall through which the raised neck extends and forms an annular passageway therebetween, and has an enlarged diameter on its side wall above the threaded portion to provide an annular passageway surrounding the disk circumference. The cap is screwed on the container over the cylindrical disk with the disk neck portion extending through the hole in the cap, and when hand tightened thereon compresses the disk on the O-ring to seal the container and isolate the threaded cap connection. The raised neck has an internally threaded bore and a valve seating surface for connecting the container with pressurizing apparatus.

Abstract: A test kit is provided for measuring the erythrocyte sedimentation rate automatically in the original blood collection tube which is of a size and is so modified to be used for the resulting testing that no further blood transfer is required. The blood collection tube is evacuated to the desired level to obtain the desired quantity of blood to be collected and contains the proper quantity of anticoagulant. The test kit of the invention includes one or more tube-like slots for maintaining the blood collection tubes stable and in a vertical orientation for the testing procedure. Each slot includes a tube sleeve vertically adjustable in each slot. Each sleeve includes an appropriate Westergren scale which is moved with the sleeve to accommodate the positioning of the initial top level of the red blood cells in the sample.

Abstract: A multi-channel ultrasonic inspection system includes an ultrasonic inspection unit which generates ultrasonic inspection pulses, supplies the pulses to a part being inspected, produces an output signal proportional to the level of echo pulses received within a predetermined gate time window following generation of the inspection pulses, and generates an alarm signal whenever the output signal exceeds a predetermined gate level. The system also includes data recording apparatus having a microcomputer, a mathematics processor chip, a control panel, and a printer. A gate reference level for each channel is stored by the microcomputer by pressing a channel button on the control panel, supplying inspection pulses to a workpiece having a standard defect, and adjusting the gain or gate level of the ultrasonic inspection unit until an alarm signal is generated. The operator then presses a START button which causes the reference levels to be printed.

Abstract: The Rapid Sediment Analyzer provides information on the size distribution of a sample of finely divided particulate matter (e.g. sand) by monitoring the weight and the rate with which the particles fall through a column of liquid (e.g. water). A digital computer connected to the Analyzer reports the particle size distribution directly.

Abstract: Apparatus for the automotive measurement of the apparent density of mud or sludge contained in a liquid, and a system for the automatic measurement of the PONSAR index and a process for measuring said index. The apparent density of one liter of clarified liquid is obtained with the aid of electronic means for measuring the immersion difference, in a clarified liquid reservoir, of a bottle successively filled with mud and clarified liquid. Detection means make it possible to measure the mud volume decanted or settled in 1/2 hour in a cylinder filled with one liter of mud-containing liquid and 1.5 liters of clarified liquid. Thus, the calculation of the volume/weight ratio then gives the PANSAR index.

Abstract: Suspensions, liquid emulsions and the like are monitored with ultrasonic waves from bottom to top of a column of such to determine if there has been alteration in the original compositions thereof, the method being particularly adapted for determining the stability of coal-aqueous slurries.

Abstract: Suspensions, emulsions and the like are monitored with apparatus which pulses ultrasonic waves through a suspension at elevations from bottom to top along a column of such suspension to determine if there has been alteration in the original composition thereof, the apparatus being particularly adapted for determining the stability of coal-aqueous slurries.

Abstract: A sampled flow of water is extracted from a water conduit 1 carrying impure water by a sampling tube 2, the pressure at a point in the sampling tube is kept constant by a constant pressure maintaining valve 4, and the sampled water passed through a filter 7. The flow rate of sampled water passing through the filter 7 is measured by a flow meter 8. A value corresponding to the total amount or level of impurity in the sampled water is evaluated by an operation circuit 9 at a prescribed time interval, based on the time-dependent change in the result of measurement of the flow meter 8 and the total amount or level of impurities in pure water is thus measured indirectly.

Abstract: In order to replace acoustic lenses, frequency units corresponding to frequencies used by the acoustic lenses and housing transmitted pulse generating means, circulators and receiving means can be selected and the signal of a gate opening at a timing at which ultrasonic waves of a sample return can be selected.

Abstract: An apparatus for testing fluid loss characteristics of a test fluid such as drilling mud under static or dynamic conditions, the apparatus having a filter medium cell which has a generally vertically disposed cylindrical wall, the apparatus further including a first chamber which is in open communication with the inner surface of the cylindrical wall and a second chamber which is in communication with the outer surface of the cylindrical wall, there being a generally vertically disposed rotatable shaft which is received internally of the cylindrical wall, the shaft being driven by a motor or the like, the apparatus being capable of providing a differential pressure across the cylindrical wall such that fluid will flow from the first chamber to the second chamber in response to the differential pressure and the liquid passing into the second chamber can be suitably measured and used to calculate fluid loss rate of the test fluid.

Abstract: An adaptable, accurate, high resolution centrifuge core measuring method using a single strobe flash per measurement uses a microprocessor controller to control the measuring method, not a computer. The controller, not the camera clock, decides when the camera data should be read. The camera data is read into and stored in the controller, not a computer. The controller reads the camera array, controls centrifuge speed, determines alignment of the proper catch tube, flashes the strobe, determines lapse time, rereads the pixels, stores and analyzes the pixel information and the other steps of the method. The controller is capable of operating in many modes. But at any point, for operator intervention the controller is adapted to let the computer intervene.

Abstract: A physical property of the solid component of a slurry, for example the percentage content of a selected element such as iron, is continuously measured. A sampling device (2) carrying a filter element is immersed in the slurry at a sampling station (A). Vacuum is applied to the sampling device (2) to cause the liquid content of the slurry to pass through the filter element, leaving the solid component deposited on the filter element as a filter cake. The sampling element is transferred to a heating station (B), where the filter cake is dried, and then to a measuring station (C), where the desired physical property is measured. The sampling device is then transferred to a washing station (D), where the filter cake is washed from the filter element so that the procedure can start again. The process is automatically controlled by a microprocessor, enabling continuous sampling of the slurry to be carried out.

Abstract: A method and apparatus for measuring the unsteady sedimentation potential of particle in a suspension comprising: inserting at least a portion of the suspension of particles in a cell, the cell having a first electrode and a second electrode; vibrating the cell to accelerate the particles in suspension; and measuring the unsteady sedimentation potential of the particles across the first and second electrodes. The cell is vibrated at a frequency in the range between 0.0001-50 khz.

Abstract: Apparatus and method for determining the level of particulate contamination within the fluid of a hydraulic system. System fluid is introduced through a non-return valve into a space where it is contained by a piston. The structure of the piston includes relatively-movable parts defining a restricted orifice to which fluid, having passed through a drilling in the piston, may escape to drain. When the piston is moved so as to tend to reduce the trapped volume, fluid is expelled from the volume through the drilling and clearance until the clearance becomes blocked by contaminants. The degree of contamination may then be derived from the distance that the piston has moved. The separate parts of piston structure are then relatively-moved to clear the orifice and allow the rest of the trapped fluid to escape, after which the orifice is reset and another volume of fluid introduced to be tested. The piston may be driven by reaction with the system fluid, or alternatively by means independent of that fluid.

Abstract: A method of determining the properties of fiber pulp by separating a batch of a predetermined volume, by measuring its temperature, and by filtering water from it by means of a pressure difference. In accordance with the present invention, substantially all the water is filtered off from the pulp mixture, an air flow is produced through the filtered pulp cake by means of a pressure difference, the resisting effect of the pulp cake on the flow of air is measured, and the pulp cake is weighed, whereafter the properties of the pulp are calculated on the basis of the measurements, from mathematical models developed for this purpose.

Abstract: A positive stirring consistometer cup includes a pair of wall blade members having radially inwardly extending blades which cooperate with radially outwardly extending blades of a paddle to uniformly apply shear throughout a substance to be tested. A split sleeve assembly eliminates an outer dead space, and an enlarged spacer member mounted on the shaft of the paddle eliminates an inner dead space, thereby enhancing the uniformity of the shear throughout the substance. A centralizing assembly centers the stationary paddle while causing a minimum of friction and wear to occur on the shaft of the paddle. In a method of using the positive stirring consistometer cup, the blades of the wall blade members and of the paddle stop in substantially aligned, coplanar relationship to facilitate cleaning of the elements after a test is concluded.

Abstract: A blood sedimentation apparatus has an upright transparent sedimentation tube (11) which can be inserted into a sample container (32) containing blood and which can filled with blood up to a zero mark (13) provided in the upper region by displacing the blood contained in the sample container. A closure (12), which includes an overflow vessel (24) and a hollow spigot (14) which communicates therewith, and which extends from above into the sedimentation tube up to the zero mark (13) can be placed onto the upper end of the sedimentation tube (11). A closure member (15) which closes the opening (16) of the hollow spigot (14) can be introduced axially into the hollow spigot (14).

Abstract: In an apparatus for measuring the rate of erythrosedimentation of the blood a bell mouthed test tube is provided, having a cylindrical part in which a calibrated and graduated sealing tube, topped with an overflow sleeve for the excess blood, slides. This overflow sleeve allows an automatic filling with blood of the calibrated tube independently from the care taken in the filling of the tapered test tube.

Abstract: The drainage quality of a pulp furnish slurry on a paper machine forming wire is predicted by the drainage tester of this invention by accounting for the effect of drainage through the paper sheet as it forms. The tester can distinguish between fast draining mechanical pulps and slower draining chemical pulps as well as predict the effects various additives will have on drainage. The apparatus includes a screen which separates furnish fibers from the slurry white water in response to a constant volume vacuum pump. Pressure differential as a function of time is recorded producing for any given furnish three distinctive points of inflection on the curve, including a first point of inflection which correlates with the wet line on a paper machine forming wire, second point of inflection which correlates with the dry line on the former and a third point of inflection which correlates with the maximum practicable removal of water from said pad by the typical former vacuum systems.

Abstract: A method for testing drilling compounds, particularly drilling fluids and cements to determine the drilling fluid and cements ability to seal porous formations surrounding the borehole. The method would generally comprise obtaining a representative sample of drilling compound for testing, particular drilling fluid or cement, that has been or will be injected down the borehole and recovered for testing. The sample of fluid is then filtered through a filter press or the like having a porous filter disk with measured size openings that can be closely controlled, or having absolute filtration ability. The sample is then filtered through the disk, usually under pressure, and the rate or the time that the drilling fluid takes to seal a specific size opening in a specific disk is recorded by the number of cubic centimeters of drilling fluids that is recovered until such a seal is established. The test is conducted for a prescribed period of time (30 min.

Abstract: Apparatus and method for determining the level of particulate contamination within the fluid of a hydraulic system. System fluid is introduced through a non-return valve into a space where it is contained by a piston. The structure of the piston includes relatively-movable parts defining a restricted orifice to which fluid, having passed through a drilling in the piston, may escape to drain. When the piston is moved so as to tend to reduce the trapped volume, fluid is expelled from the volume through the drilling and clearance until the clearance becomes blocked by contaminants. The degree of contamination may then be derived from the distance that the piston has moved. The separate parts of piston structure are then relatively-moved to clear the orifice and allow the rest of the trapped fluid to escape, after which the orifice is reset and another volume of fluid introduced to be tested. The piston may be driven by reaction with the system fluid, or alternatively by means independent of that fluid.

Abstract: Apparatus for determining sedimentation rates including a first support means having a plurality of tubes, held vertically and spaced, and a second support means having a plurality of tubes, of larger diameter than the tubes mounted on the first support means, and each able to receive a blood sample, the tubes being vertical and spaced on the said second support means, and a single suction device mounted at the upper end of the first support means, the support means being movable with respect to each other between a first position in which the tubes of the first support means are separated from the tubes of the second support means, a second position in which the lower ends of the tubes of the first support means dip into the tubes of the second support means, and a third position in which the sedimentation of the red blood corpuscles takes place.

Abstract: A complex liquid, such as a biological liquid, is stratified, as by centrifugation in a tube, into constituent layers. The most dense or heaviest constituent layer is measured volumetrically by physically expanding the entire layer with a cylindrical float which is inserted in the tube and which occupies the portion of the tube also occupied by the constituent layer being measured. The axial extent of the expanded layer is measured to provide an indication of the volume of the layer being measured. The end of the tube proximate to the layer being measured contains a plug of a more dense material which is immiscible with the subject liquid and into which the float will settle during centrifugation. The float thus settles into the plug of dense material and "floats" therein so as to extend through the entirety of the layer being measured.

Abstract: A novel meter is provided for measuring erythrocyte settling rates. It includes a base supporting a rack adapted to hold an array of tubes at an optimum settling angle and at least one tube adapted to contain blood samples, the tube including an upper window of predetermined length and a lower window of predetermined length below the upper window and separated therefrom by an opaque section, each window permitting passage of ambient light therethrough. A timer is provided which is actuated by the passage of light through the windows when the tube contains blood, to determine the rate at which the erythrocytes settle.

Abstract: System for detecting the forming of depot inside a transport channel for transporting particles in a light transparent carrier fluid, comprising a light transmitter, a light receiver, a bifurcated glass fibre cable of which an end is installed in the wall of a transport channel. One branch of the cable is coupled to the light transmitter and the other branch is coupled to the light receiver, and the output of the light receiver is connected to a discriminator circuit comprising a converter for converting the effective ac voltage component in the received signal into a dc voltage component and a comparator in which the dc voltage signal is compared with a predetermined threshold signal, which discriminator circuit is coupled to a visual indicator unit.

Abstract: An apparatus includes a main housing with a permeable cylindrical sleeve in the main housing to simulate a rock formation through which a well is drilled. A compartment is defined outside the sleeve and a solids-containing fluid is introduced into the interior of the sleeve and pressurized, so that the fluid passes through the sleeve and into the compartment, leaving a filter cake on the inside of the sleeve. A probe extends through the sleeve to simulate a drill string, and the probe can be moved toward and away from the inside surface of the sleeve. The apparatus includes a means for determining the filter cake thickness, preferably ultrasonically.

Abstract: An apparatus for blood analysis to determine the rate of corpuscle sedimentation. The apparatus has a first support (1) with several graduated tubes (4) open at both ends and held vertically in spaced relation on the first support. The tubes (4) have enlarged lower ends (4b) which can diverge. A second support (2) has blood sample containers (13) of larger diameter than the vertical tubes on the first support. The containers (13) are spaced apart on the said second support, the same distance as the tubes on the first support so the containers are respectively, vertically below the tubes. Sealing and flow inducing members engage in the diverging lower ends (4b) of the respective tubes. The support means (1, 2) are movable with respect to each other between a first position in which the tubes are vertically above the containers, and a second position in which the lower ends of the tubes are immersed in the containers.

Abstract: A bore hold hydraulics simulator for drilling fluid is disclosed, in which the drilling fluid is flowed along a permeable partition which divides a first volume containing the drilling fluid from a second volume adapted to collect filtrate passing through the permeable partition. A pressure differential is established across the partition so as to promote the passage of filtrate into the second volume, and a vessel is provided for collecting the filtrate passing into the second volume.

Abstract: A bore hole hydraulics simulator for drilling fluid has a pump for flowing the drilling fluid along a permeable partition which divides a first volume containing the drilling fluid from a second volume adapted to collect filtrate passing through the permeable partition. The first volume is a substantially cylindrical passageway to simulate a bore hole, having within it a rod-like member simulating a drill string. The partition is a sleeve-like insert located adjacent the rod-like member. The second volume is a chamber surrounding the insert. The rod-like member includes a device for measuring the thickness of a cake build-up on the sleeve-like insert within the passageway. The output of the pump can be adjusted in response to measurements of cake thickness, in order to maintain a substantially constant shear rate past the cake.

Abstract: A procedure for accurately determining size distribution of macroaggregate and colloidal particles in a solution wherein the solution is passed through a first capillary filter of selected pore diameter and then through a tortuous path provided by a fibrous filter composed of fibers having affinity for the colloidal substance.

Abstract: A system for testing drilling mud includes viscosity measuring tubes and other instruments for testing the parameters of drilling mud. The mud is heated to an elevated temperature and recirculates in a closed flow path which includes the measuring instrumentation. A diaphragm pump successively withdraws a column of mud from the flow path and discharges mud into the flow path to effect the recirculation. A pumping column between the flow path and the pump contains a column of drilling mud which thermally isolates the pump from the hot mud in the flow path.

Abstract: In order to safely interfering signals caused by interfering volumina like e.g. air bubbles existing in a coupling medium from signals generated by workpiece defects in the ultrasonic testing of workpieces according to the pulse-echo-method, it is suggested that at the appearance of a signal in the time between transmitting pulse and surface echo-signal crossing an adjustable threshold during a test cycle, all signals of the same test cycle falling within the range of anticipation for workpiece defects will be suppressed.