Abstract: A technique for assessing electrostatically deposited coatings of powder to be later fused into a surface finish. Powder deposited by the coating process onto a test piece or an unimportant part of an actual article is disturbed by, for example, a series of puffs of compressed air. The removal of the powder by the disturbance is monitored. In one arrangement infra-red light is shone through the coating and the change in transmissivity with each puff of air is measured to give an indication of the quality of the powder deposit.

Abstract: The dust producing properties of a pigment or dye are measured under conditions which close approximate those during handling. A vessel with baffles having pigment or dye therein is rotated for a specified time while air is drawn through the rotating vessel by a specified amount of vacuum applied downstream of the vessel. The baffles disturb the pigment or dye in the vessel, creating dust particles which are entrained in an airstream created by the vacuum. Larger particles trapped in this vacuum are removed by a separator, while the dust particles are trapped in the airstream are trapped by a filter. The dusting properties of the pigment or dye in the vessel may then be determined by weighing the filter.

Abstract: Materials to be tested for resistance of immersion swelling, drying shrinkage, thermal expansion and thermal contraction under light exposure are placed on a mount on a rotating shaft which immerses the sample in water, heats and dries it, and exposes it to light before cooling it by again immersing it in water. The samples may be simultaneously exposed to air pollutants by adding gases to a corrosion resistant chamber enclosing the rotating shaft. The chamber enclosing the rotating samples is composed of a lower tank base and a cover fitting into a liquid seal well on the tank base. The cover is fitted with fluorescent lights, an infrared heating strip, a thermocouple and a viewing port. A controller with indicator for the radiant heating strip and a speed control on the rotating shaft drive motor together with "run" and "pause" controls permit selection of the exposure cycles and their conditions.

Abstract: An apparatus for nondestructive, absolute measurement of the properties of solid materials can be derived from the behavior of a body penetrating into the materials, having a guidance device which guides the penetrating body on the surface of the materials and an electrical evaluation circuit. The penetrating body is a probe-tip insert in a single-pole probe set on the material to measure the thickness of thin coatings in the range of several 1000 .mu.m and less. An electrical drive is connected to the guidance device and presses the penetrating body with a specific but variable force onto the surface of the material, and a voltage output by the probe representing the coating thickness is passed on to an evaluating circuit.

Abstract: A sensor for use in testing the effect on materials of irradiation and weathering uses solar cells (10) to provide power and uses a transmitter (3) to continuously read out its measurements without interrupting the testing process. The sensor features a number of receptor cells (2) for various spectral ranges and a temperature sensor (17), whose measurements are multiplexed and transmitted under the control of a control logic 18. The receptor cells (2), the photo cells (10) and the electronics (16) are all contained in a preferably cylindrical quartz glass tube (4). The self-contained nature of the sensor and the continuous, immediate read-out of measurements eliminate external wiring requirements and speed up the testing process.

Abstract: A light and weather resistance testing apparatus (9) is provided with a sensor (1) located in the plane of the testing samples (14). The sensor (1) uses a transmitter (4) for wireless transmission of signals representing radiation received to an antenna (3) disposed on the wall (8) of the apparatus housing. The sensor (1) has multiple receptor cells (6) for various spectral ranges. The sensor (1) is powered by solar cells (7) located on the sensor housing. A plotter and display unit (13) can be connected to the apparatus for read-out of irradiance and irradiation. The wireless transmission of data from sensors to the display unit permits continuous measurement during rotation of samples and sensor.

Abstract: A method and apparatus are disclosed for magnetically measuring a coating on a magnetizable material. The apparatus includes a plurality of magnets flexibly connected to one another with the magnets preferably provided on a strap of flexible material. Each magnet has a coating with a predetermined thickness provided over only a first portion of the magnet and preferably over one pole of the magnet. The coating of each of the plurality of magnets differs in thickness from one to another. The magnets contact the coating to be measured at a second portion of the magnets and the coating of each magnet is then contacted sequentially with a member of a magnetizable material. If the magnet is lifted with the member, the coating to be measured is greater than the thickness of the coating of the magnet. If the magnet is not lifted with the member, the coating to be measured is less than the thickness of the coating of the magnet.

Abstract: In a method and apparatus for testing the duplicating characteristics of pressure-sensitive duplicating sheets and duplicating sets produced therefrom, a stroke grid is drawn on the duplicating sheets to be tested by means of a marking stylus which is actuated either by mechanical or electromechanical devices to apply a selective a contact force, with the grid being evaluated either visually or by photoelectric reflectance measurement, the stroke grid consisting essentially of a plurality of individual strokes which overlap or are closely adjacent but which do not intersect.

Abstract: A method and apparatus which dynamically determines the location of a fabric layer bonded within a moving calender strip of elastomeric material by passing opposed surfaces of the strip partially about a respective one of a pair of measuring rolls forming a part of a two pair over-under rolls. Sensors are connected to each of the measuring rolls and provide a signal in relationship to the rotational speed of each of the measuring rolls. The two signals are compared and provide a third signal indicating the relative position or balance of the fabric layer with respect to the two outer strip surfaces. Since the fabric layer when under the same dynamic tension and conditions will achieve a specific elongation its radial position with respect to the surfaces of the measuring rolls will control the rotational speed of the rolls when contacted by the moving surfaces of the calender strip.

Abstract: A method and apparatus for analyzing the structural formation and surface properties of fibrous sheet materials, particularly printing papers, are described. The method requires advancing a marker over a substantial area of the sheet to be tested. The marker is urged into contact with the sheet so that it exerts a pressure on it, typically of printing process magnitudes. The marker is any material which produces an image the intensity of which is proportional to the pressure exerted upon it by the test sheet. A preferred marker is graphite. The image produced is equivalent to those produced by Beta ray formation analyzers and may be evaluated by a missing dot technique commonly employed in rotogravure print quality evaluations.

Abstract: A method and apparatus for preparing a proof or sample of an ink (as herein defined) as a preliminary to its being employed in a printing or coating process to enable its color and coating capability to be determined. A quantity of the ink is applied to a first roller the surface of which is engraved. The ink is evenly distributed over the roller using a doctor-blade set so as to wipe the roller surface clean and leave the ink only in the engravings. A second roller of resiliently deformable material is moved into contact with the inked roller so causing ink to be transferred to the surface of the second roller until equilibrium is reached and a sheet of the substrate to be inked or coated is introduced into the nip between the two rollers. Means is provided for cleaning the rollers after use.

Abstract: An apparatus for measuring the swelling or shrinkage of a specimen in a fluid consists of a container in which the fluid can be accommodated and which has a lid with a suspension device for the specimen, and a transducer which is affixed to the specimen at a location spaced from the point of suspension, for affecting a sensor connected to a recording equipment. In measuring, the movement of the transducer caused by the swelling or shrinkage of the specimen in the fluid can be continuously recorded.

Abstract: A technique for accurately and repeatably measuring the depths of junctions between adjacent layers in a semiconductor wafer, even when the depths are relatively shallow. A groove is formed in the surface of the wafer, with a cylindrical grooving tool that is inclined to the planar surface of the wafer, to form a groove that is tapered in width and depth. The wafer is then conventionally treated to enhance the contrast between the layers as they are exposed on the groove surface. Since each planar junction intersects the groove surface at an angle, the corresponding junction line appears as a part of an ellipse, and exhibits a well defined peak at the center of the groove. Direct measurement of the depth of the groove at this point, using a standard profilometer, provides the desired junction depth.

Abstract: Apparatus for use in conducting both static and dynamic thermomechanical analysis includes a load member, one end of which is supported by the sample located in a sample receptacle, eventually in a selected gas atmosphere, in heat equilibrium and the other end of which is loaded statically by a weight or dynamically by the armature of an electromagnet.

Abstract: This invention relates to a method of and a device for the weighted measurement of quantities of liquid per unit area and/or the relative quantities of a liquid per unit area by means of an acoustic sensor. More particularly, the method permits the measurement of quantities of liquid and/or relative quantities of a liquid per unit area at the outlet of a nip formed by two rollers completely or partially covered by the liquid and/or liquid mixture concerned, the rollers rolling one upon the other and the layer of liquid in the nip being split at the nip outlet. Splitting of the layer of liquid occurs particularly in printing machines and glue applying machines, to which the invention can accordingly be applied.

Abstract: An apparatus and method is described herein which simulates and applies soil shear stress conditions to test pipe segments and thereby induces the mechanical soil stress effects upon adherent pipeline anti-corrosion protective coatings. A test pipe segment having an adherent anti-corrosion protective coating is emplaced centrally in a test apparatus housing chamber, having both a concentrically-located soil reservoir in contiguous contact with said test pipe segment, and a gas pressure reservoir surrounding said soil reservoir. Desired movements of said test pipe segment are controlled and regulated by a universal testing machine. Gas pressures in the gas pressure reservoir exerts pressure on the soil reservoir, thereby simulating soil stress forces on the centrally disposed pipe segment with its adherent anti-corrosion coating.

Abstract: A printing press blanket gauge for measuring the thickness of blankets used in printing presses consisting of a casing containing measuring and indicating means such as a dial test indicator, the casing having projecting from it two pointed probe members capable of penetrating a printing blanket without damaging it and making electrical contact with a metal surface below the blanket, there being arranged between the pointed probe members a probing means connected to the dial test indicator and within the casing a source of electricity connected to the probe members through a lamp or other signalling means, the arrangement being such that when both the pointed probe members and the probing means are pressed against the surface of a printing blanket the pointed probe members pass through the blanket and are electrically connected externally of the casing through the metal surface beneath the blanket thus causing the lamp to illuminate and the dial test indicator to give a direct indication of the thickness of t

Abstract: A measuring device for measuring the change in time-dependent thickness of the paint layer without any need of direct contact thereto. The device is provided with an optical arrangement which is well-known as Michelson-interferometer in principle, and is effective to obtain sharp and clear interference fringes even though the paint layer has a low reflectivity. It is also possible at laboratory side to observe the change of the paint layer under the circumstances to which the paint layer may be exposed actually.

Abstract: A coating thickness measuring apparatus for step and repeat coating systems, including; a support member; a common support assembly mounted for pivotal movement about and along a vertical axis; a measuring probe carried by the common support assembly and movable with respect thereto along a horizontal axis; a calibrating disc carried by the common support assembly for rotation with respect thereto about a horizontal axis, having an opening for reception therethrough of the probe and having a plurality of angularly spaced calibration standards movable into selective alignment with the probe; actuators for moving the probe along its horizontal axis, for vertically moving the common support assembly and for rotating the calibration disc; stroke limiting means to halt probe movement between its extreme positions; an indexing bar having a plurality of variably spaced openings; an indexing pin for securing the support member into one of the indexing bar openings; and sensing switches developing signals indicative o

Abstract: Apparatus is provided for imposing measurable wear on the surface of a magnetic recording disk and for determining the relationship of read/write characteristics due to such wear. A dynamic air bearing separates the interface between the disk surface and a slider head. The imposed wear changes the relationship between the head and disk and the changes provide measurable data for experimental evaluation of read/write slider flying dynamics.

Abstract: An inspecting liquid is dropped onto a resist layer formed on a gravure printing plate and is allowed to permeate the resist layer to reach the printing plate so that a short circuit is formed between the inspecting liquid and the printing plate. The time required for forming the short circuit is measured to determine the conditions of the resist layer thereby to improve the quality of the finished printing plate.

Abstract: A hand held device (12) having a forward open window portion (14) adapted to be pushed downwardly into the frost on a surface, and a rear container portion (22) adapted to receive the frost removed from the window area. A graph (FIG. 4) on a side of the container enables an observer to determine the density of the frost from certain measurements noted. The depth of the frost is noted from calibrated lines (28) on the sides of the open window portion (14).

Abstract: In providing an adhesive connection or a seal using a thermoplastic adhesive for securing materials together, a thermochrome dye is added to the thermoplastic adhesive so that it provides a color change in the temperature range between the temperature where a satisfactory moistening effect is achieved and the temperature where the satisfactory moistening effect is no longer present.

Abstract: To provide for more reliable determination of resistance of sample surfaces to light and weather influences, test apparatus is equipped with a radiation-measuring device. A portion of radiation used for testing is guided to the measuring device, by quartz guides, spectrally dispersed, and measured as to intensity and/or dosage in one or several pre-selected spectral regions. Tests may use natural or artificial radiation, and a measuring device may be stationary or movable relative to a radiation source.

Abstract: A high pressure mercury arc lamp such as the light source in a projection aligner is utilized in a photo resist calibrating process. The light source is utilized with narrow band interference filters centered on the mercury emission lines to isolate exposures to one narrow band of wave length at a time. The assumption is made (incorrectly) that the energy in each band of wave lengths from the high pressure mercury arc lamp is equal. Exposure to a narrow strip of photo resist--preferably in the form of a bar graph--on a semi-conductor wafer is made. A single wave length band is exposed for each bar of the graph. As each bar of the graph is scanned, exposure is varied in known ways (eg. linearly variable neutral density filters, changing apertures size, and/or varying exposure from changing wafer motion). The wafer is then developed and examined to determine the ratio of sensitivity for each wave length. A light meter is then placed in and exposed to the same high pressure mercury arc lamp.

Abstract: A gauge and method for measuring the cure shrinkage of polymeric concrete. Blades dependent from a bridge are inserted in poured concrete. Movement of the blades with the concrete is measured by a proximity sensor and associated instrumentation records the movement continuously during the cure cycle.

Abstract: An apparatus is disclosed to simplify the measurement of tack time which is the length of time necessary to heat the prepreg to a tacky condition. A strip of a prepreg specimen is wrapped around an elongated lower support member, and thereafter an upper support member is fixedly connected to the lower support member to secure the prepreg in place. The thickness of the coiled prepreg causes the upper support member to flex upwardly in a bow-like configuration defining a pair of channels between the support members on either side of the coiled prepreg. A head member, having a planar bottom surface, includes a pair of gripping members which are received in the channels between the support members for gripping the prepreg specimen. An electrically controlled air cylinder is provided having a reciprocating piston which is connected to the head member for sequentially moving the prepreg specimen into and out of contact with a heated platen.

Abstract: A manually portable fluid ink tack tester (10) for sampling and testing the tack of printing inks during press runs has two engaged, rotating rolls (25,26) mounted on parallel axes and in rolling contact on the tester frame (15). One (26) is extended outwardly from the frame (15) to expose the surface of the roll for contacting an ink coated surface and receiving an ink sample therefrom. After receiving the ink, the tester (10) is removed from the ink coated surface and a motor (35) in the tester (10) rotates the rolls (25,26). The force necessary to split the ink between the two rolls (25,26) is measured (13,40) and displayed (13,48), giving an indication of the tack of the ink.

Abstract: A device for measuring the thickness of coatings comprises a rotatable drill, the cutting edge or edges of which are at a 45.degree. angle to the axis of the drill. The drill is manually operated by means of a finger disc and guided and steadied during its operation in a through-going bore in a guide plate resting with an anti-slide surface on the coated surface, the thickness of whose coating is to be determined. The conical cut made by the drill is observed in a microscope, and the width of the circular band is noted on an in-built micrometer scale. Owing to the cutting angle being 45.degree., the said width is equal to the thickness of the coating.

Abstract: An improved method for indicating the temperature to which a heat-deformable polymeric material coated with a thermochromic paint has been heated is disclosed. The improvement comprises the addition to the thermochromic paint of a non-thermochromic compound selected from the group consisting of the sulfates, hydrated sulfates and nitrides of boron, aluminum, tin, lead, arsenic, antimony, bismuth, zinc and phosphorus; the sulfides and hydrated sulfides of boron, aluminum, bismuth and phosphorus; the oxides and hydrated oxides of boron, arsenic, antimony and phosphorus and the salts, organic derivatives and free acids of the oxyanions of boron, arsenic, antimony and phosphorus.

Abstract: A method is disclosed for determining the dispersion of carbon black in elastomeric slabs by cutting a slab to form a planar surface and moving a height measuring transducer stylus over the planar surface. The transducer stylus provides an output current at a voltage which varies in correspondence to the relative height of roughness peaks on the planar surface. Accordingly, the size of the peaks determines the size of carbon black agglomerates and the frequency of peaks for a predetermined range of height is determinative of percent dispersion of the carbon black.

Abstract: Apparatus for testing the fitness of the multiple copy sets for handwritten copies. The form set to be tested is placed on an inclined supporting plate and is clamped to the supporting plate by a slotted hold down plate. A writing instrument, which includes a spring loaded writing implement, is carried by a carriage so that the tip of the writing implement contacts the form set through the slot. The carriage is movable so as to move the tip of the writing instrument along the slot. The writing implement is supported so that the tip contacts the form set substantially without pressure in a starting position. As the carriage is shifted in the direction of increasing ascent of the supporting plate the bearing pressure of the tip of the writing implement increases as a function of the path of travel. The test line produced on the different sheets of the set is a measure of the quality of the copies.

Abstract: A means is disclosed for producing whiskers with a laboratory apparatus that simulates an electrostatically assisted gravure press. The apparatus does not employ the dynamic printing conditions normally found on a printing press, but utilizes static conditions to reproduceably generate whiskers as a means for assessing the whiskering tendency of the ink or paper involved.

Abstract: A digital computer is connected to various sensors and devices on a strip line, including a gauge located downstream of a coating bath for measuring coating thickness on the strip. The computer examines the coating weight data obtained from the measuring gauge and determines: (1) the average coating weight on each side of the strip; (2) the total average coating weight on both sides of the strip; (3) the coating weight at the conventional ASTM weigh-strip-weigh test locations on the strip; and (4) the minimum spot total coating on both sides of the strip. The computer then compares these data with target (set point) data entered by the operator and makes the following corrective adjustments: (1) a pressure correction factor is adjusted if either the total coating or the minimum spot coating does not meet required specifications; and (2) air knife position is adjusted if necessary to balance the coating from edge to edge and from side to side.

Abstract: An article comprising a polymeric material and coated with a thermochromic paint. The improvement comprises the addition to the thermochromic paint of a non-thermochromic compound selected from the group consisting of the sulfates, hydrated sulfates and nitrides of boron, aluminum, tin, lead, arsenic, antimony, bismuth, zinc and phosphorus; the sulfides and hydrated sulfides of boron, aluminum, bismuth and phoshorus; the oxides and the hydrated oxides of boron, arsenic, antimony and phosphorus and the salts, organic compounds and free acids of the oxyanions of boron, arsenic, antimony and phosphorus.

Abstract: A device for measuring the adhesion forces in a closure seal of a container, the seal being formed by a membrane adhering to the neck of a container and by a pad retained at the base of the cover of the container, adhering together, wherein it comprises a plunger with an adhesive and equipped with lateral guides and disposed in the recess of a shoe of which the sides form inclined planes adapted to the guides of the plunger and of which the base is provided with means for retaining the pad, the shoe being connected to a dynamometer.

Abstract: A rheometer comprises adjacent surfaces moveable relative to one another e.g. a pair of rollers, means e.g. a motor for moving one or both surfaces and means for measuring the effect of or on the movement when a sample under test e.g. a sheet moulding composition is placed between and in contact with the surfaces.

Abstract: A thermochromic paint, which changes color when heated to a certain temperature, and which is particularly suited for use on plastic substrates which are subject to oxidative degradation is disclosed. The improvement comprises the addition to the thermochromic paint of a non-thermochromic compound selected from the group consisting of the sulfates, hydrated sulfates and nitrides of boron, aluminum, tin, lead, arsenic, antimony, bismuth, zinc and phosphorus; the sulfides and hydrated sulfides of boron, aluminum, bismuth and phosphorus; the oxides and hydrated oxides of boron, arsenic, antimony and phosphorus and the salts, organic compounds and free acids of the oxyanions of boron, arsenic, antimony and phosphorus.

Abstract: Apparatus for determining the internal stress within electrodeposited metals is disclosed. The apparatus includes an improved spiral contractometer wherein the spiral substrate is coupled directly to a dial indicator without the use of a gear system. A rod, passing between the dial indicator and the lower end of the spiral substrate, causes a dial indication for changes in the radius of curvature of the spiral substrate. To determine the internal stress that is created within metal electrodeposited from a particular electrolytic plating solution, the spiral contractometer is submersed in that plating solution and connected as the cathode of a galvanic cell. An anode, consisting of the type of metal being electrodeposited, is supported in a precise position relative to the spiral substrate and a constant current is supplied between the anode and the spiral contractometer for a precise period of time to electrodeposit a controlled amount of metal on the spiral substrate.

Abstract: The invention concerns an improved device for testing textile samples in the laboratory. The device includes a tank holding a heating liquid. Test containers attached to test container holders are placed in the tank and containers and holders rotated. Rotation is achieved by transmitting the drive from rolls positioned on drive shafts to drive wheels forming an integral part of the container holders.

Abstract: A method of forming a continuous film of an elastomeric latex and a phenolic resin comprising spraying a plurality of coats of the aqueous admixture onto a nonadherent surface. The nonadherent surface is at a temperature of 120.degree. F. or greater and each coat of the aqueous admixture is less than about 0.7 mil dry film thickness. The film so formed can be tested for physical properties and the testing results are capable of being correlated with the performance of glass fibers with the aqueous admixture coated thereon for reinforcement of elastomeric matrices.

Abstract: This invention relates to a testing apparatus for light- and weather-resisting properties, with a sample room having a gas discharge radiator arranged therein, as well as to a mirror placed between this radiator and the samples, selectively reflecting the infrared portion of the radiation and being permeable to the visible and ultraviolet portion thereof, and to an additional mirror, selectively reflecting the visible and the ultraviolet portion of the radiation and transmitting the infrared portion thereof.

Abstract: Set points for thicknesses of coatings on opposite sides of a sheet are determined in response to measurements of the thickness of each coating. A computer responds to the two thickness measurements to derive indications of the spread of values of the measurements for each coating. The computer derives an additional indication of the spread of values for the total thickness of the two coatings. In response to the indications of the spreads of values for the coatings and the total coating thickness, minimum allowable average values for the two coating thicknesses and the total coating thicknesses are determined. The set point values for the two coating thicknesses are calculated from these minimum values, with consideration given to predetermined maximum and minimum ratios of the two coating thicknesses.

Abstract: Apparatus for testing a surface coating on a glass container. In this apparatus, a glass container is chucked in place on a movable carriage. A second glass container is held in a fixed position above and touching the first glass container. A load of a pre-determined magnitude is then applied normal to the second glass container, the load thereby being transmitted to the first glass container. The carriage is moved to cause the two glass containers to translate relative to one another. The force required to move the carriage is transmitted through a load cell which gives an output signal indicative of the force. The surface coatings applied to the glass containers should withstand a normal load of about one hundred pounds before breaking down and allowing the glass containers to scratch one another. If a scratch occurs during the test, the force required to move the carriage will increase and this may be easily seen.

Abstract: A large particle sized silica sol and a fluorescent dye are mixed together and applied as a coating to a substrate with the application monitored during coating by a light which renders the fluorescent dye visible; if the coating is blotched or uneven, corrections can be made during the run to provide a uniform coating.

Abstract: A testing device is capable of automatically performing a uniform and accurate test to determine the cure of a film of paint or the like on a test panel. The tester includes a powered rub weight wrapped, at its point of contact with the panel, with a solvent saturated material that rubs on the panel as the weight is caused to move back-and-forth along the painted surface. A drive mechanism shifts the rub weight, which is of a predetermined weight, at a constant length and speed of stroke and a counter records the number of strokes required for the solvent to penetrate the film.

Abstract: The invention relates to a lacquer hardness testing apparatus comprising a wheel formed around its outer periphery with a sharp central edge and a weight exerting its pressure on said wheel. The apparatus comprises a horizontal shaft rotatably supporting said wheel at one forked end and having its other end operatively connected to a vertical lever through means permitting an angular movement between the two members. The vertical lever is connected in the same manner to one end of another horizontal lever carrying said weight at its opposite end, said weight thus exerting a constant force on said wheel irrespective of the position of the lacquered surface to be tested. This apparatus is intended more particularly for testing the degree of curing of lacquered surfaces of the bodies of motor vehicles.

Abstract: A sampling system monitors a gas stream of a power generator and automatically samples the gas stream if its characteristics indicate that a material in the power generator is being thermally degraded. A gas stream monitoring device generates a first signal if it detects degradation occurring. A time-delay relay determines whether the first signal is continuous, and if it is the relay acts to prevent the monitor from monitoring the gas stream. If the first signal then terminates, a second signal is generated which activates an alarm and permits gas to flow into a sampling device. The sampling device has three sections which collect large particles, small particulates, and vapors and gases. The products collected can be analyzed to determine which material in the power generator was thermally degraded.

Abstract: The tester comprises basically a four wheeled carriage, a scale arm containing graduations attached to the carriage in a counterpoised condition about a pivot axis, and a rolling, round fluted cutting tool coupled to the carriage and to the scale arm. The cutting tool, as the carriage is drawn across a test surface, leaves an indented track of the cutting flutes. The width of the track marks is a function of the coating hardness and applied load.