Anton Paar Gmbh

Other

Anton Paar Kg

Gerhard Raffer

Alfred Wagendristel

Herwig Bangert

Manfred Krenn

A rotational viscometer contains a measuring shaft that can be rotated at a specified rotational speed, a measuring part that is carried by the measuring shaft and that can be lowered into a sample, and a detection unit for determining the angle of torsion of the measuring part relative to the driven part of the measuring shaft. Accordingly, a twistable element is inserted into the measuring shaft, preferably in the section of the measuring shaft close to a motor. The detection unit is moved along with the shaft and determines the relative twist or the angle of torsion (twist) between the shaft part located on the motor side relative to the twistable element and the shaft part located on the measuring-part side. The output signals of the detection unit are fed to an evaluation device as the basis for determining the viscosity of the sample.

Rotational viscometer

A process and an apparatus determine the rheological properties of medium samples. The normal forces arising in a measuring gap perpendicular to the measuring surfaces are recorded with a recording unit and the height of the measuring gap is adjusted with a positioning unit and with positioning elements actuated by the positioning unit. During the measuring procedure the initial height of the measuring gap is kept constant, by the values of the normal forces arising being linked with a calibrating function, and in that, upon detection of normal forces arising, values derived from the calibrating function are drawn upon as control signals, with which at least one sliding actuator acting on at least one of the two measuring elements is driven, which by position adjustment or height adjustment of the respective measuring element performs an immediate resetting of a height of the measuring gap, changed by the normal forces exerted by the medium sample to be examined, to the initial spacing set originally.

Process for determining the rheological properties of materials

Process and rheometer for determining the rheological properties of materials

A rotational rheometer or viscometer has a measuring motor for driving a measuring shaft which carries a measuring system, particularly a measuring head supported by a shaft portion, which may be contacted with a substance to be examined. Measuring data are introduced into the calculation of the properties, particularly the viscosity, of the substance. The measuring system has a characteristic identification with data referring to its properties, such as the geometry, the type, and/or the construction of the measuring head. An encoder module enables contactless reading the information. The data transmission path between the measuring system and the uptake or receiver unit has at least one section where the data may be transmitted wirelessly or over an air transmission path or air main path.

Rotation rheometer of viscosimeter

A rotary rheometer has a measurement motor ( ) rotating a measuring shaft ( ) on which an upper, and in particular a plate-shaped or conical, measuring part ( ) is fastened. A measuring gap (S) is formed between the first measuring part ( ) and a rotationally fixed lower, preferably plate-shaped measuring part ( ). The substance ( )&mdash;in particular fluid, gel, or the like&mdash;to be tested is introduced into the measuring gap (S). The width of the measuring gap (S) can be adjusted by displacing the two measuring parts ( ) relative to each other. A heating or tempering unit for the lower measuring part ( ) is arranged below the lower measuring part ( ). To heat or cool or temper the upper measuring part ( ) at least one heat pump ( ), and in particular at least one Peltier block, is provided by which heat can be supplied to or removed from the upper measuring part ( ).

Rotary rheometer

A rotational rheometer has an integrating motor ( ), which rotates a measuring shaft ( ) supporting a first measuring element ( ), there being formed between this first measuring element ( ) and a further, fixed measuring element ( ) a measurement gap (S), into which is introduced the substance to be tested ( ), in particular fluid, the depth of the measurement gap (S) being variable by the adjustment of the two measuring elements ( ) relative to each other, and a device being provided to determine the distance between the two measuring elements. At least one inductive or at least one magnetic position sensor ( ) is supported by one of the two measuring elements ( ). The first measuring element ( ) or a device ( ) disposed on this measuring element ( ) can cause the position sensor ( ) disposed on the other measuring element ( ) to respond, or can cause the output signal, e.g. impedance, resistance,or voltage, of this position sensor ( ) to be modified, and the output signals of the position sensor ( ) are supplied to an analyzing unit ( ).

Rotational rheometer

A rotary viscosimeter which has a rotary measuring cylinder that is disposed in a cylindrical measuring cup holding the sample to be tested in a measuring gap formed between the cylinder and the cylindrical wall of the cup. Forces required to rotate or angularly deflect the cylinder are measured and used to determine the viscosity of the sample. The temperature of the sample in the gap is maintained uniform by constructing the measuring cup of a good heat conducting material and surrounding it with a control cup, also constructed of a good heat conducting material, and the cups are configured to form an isolation gap between them. At least one heat pump in heat conducting contact with an outer surface of the heat control cup controls the heat flow to and from the heat control cup, and a good heat conducting contact area is formed between the cups at the upper ends of the measuring cup to provide a controlled heat flow to or from the measuring cup.

Rotary viscosimeter

A rotary viscometer has a measuring motor which drives a measuring shaft that carries a disc mounted in an air bearing of a stator. The viscometer has a normal force measuring drive defined by at least one position sensor for determinal movements of the measuring shaft on the basis of viscoelastic properties of the substance to be investigated, such as a liquid. To measure the normal force in the region of the air bearing, the position sensors are disposed in the region of the air bearing on the stator, and in particular they are embedded in the stator and absorb the movements of the disc in the axial direction of the measuring shaft with resect to the stator.

Rotary viscometer with an air bearing

A micro hardness testing device (durometer) comprises a permanent magnet having a plunger. A spring arrangement has at least one strain gauge that provides a signal on bending of the spring arrangement. The spring arrangement is carried by the plunger. A penetration body is loadable via the spring arrangement, and the plunger is connected to a current supply. The strain gauge signal is converted to an electrical signal as a measuring signal for the force applied to the penetration body. The measuring signal is supplied to an evaluation unit. The plunger, the permanent magnet and the spring arrangement are enclosed by a housing adapted for insertion into a revolvable nose piece of a microscope. The housing approximates the shape and dimensions of an objective insert for the microscope. The penetration body is adjustable in an optical axis of the microscope.

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Graz, Austria

Gerhard Raffer