Abstract: A sensor for measurement of small-angle or small-displacement position of a rotational rheometer incorporates multiple independent capacitors in a symmetric relationship. The device presents its output as a standard bridge configured differential signal, which can be interpreted and measured using conventional electronic demodulation means. The device includes an excitation array, a measurement array and an active rotor array. The active rotor array is coupled to a drive shaft of the rotational rheometer and measured relative to the measurement and excitation arrays. The active rotor array is driven by an electrical signal that is precisely matched to signals detected by the measurement array. By driving the active array with signals sensed by the measurement array, the sensor allows for reduced sensitivity to unwanted signals not in the measurement direction.

Abstract: A system for making extensional measurements on a sample includes an armature, a motor drive shaft, a moveable cylinder, and a fixed cylinder. The motor drive shaft is attached to the armature. The moveable cylinder is mounted on the armature. The sample is stretched between the moveable cylinder and fixed cylinder by the rotation of the moveable cylinder around the axis of the fixed cylinder and rotation of the moveable cylinder about its own axis. The resistance of the sample produces a torque on the moveable cylinder and the fixed cylinder. The torque is measured on the moveable cylinder or on a transducer shaft attached to the fixed cylinder. The system is adaptable to a commercial rotational rheometer.

Abstract: A sensor for measurement of small-angle or small-displacement position incorporates multiple independent capacitors in a symmetric relationship. The device presents its output as a standard bridge configured differential signal, which can be interpreted and measured using conventional electronic demodulation means. The device includes an excitation array, a measurement array and an active rotor or linear array. The active array is coupled to a moving object and measured relative to the measurement and excitation arrays. The active array may be floating, grounded or driven by an electrical signal. However, driving the active array with signals sensed by the measurement array allows for reduced sensitivity to unwanted signals not in the measurement direction.

Abstract: A sensor for measurement of small-angle or small-displacement position of a rotational rheometer incorporates multiple independent capacitors in a symmetric relationship. The device presents its output as a standard bridge configured differential signal, which can be interpreted and measured using conventional electronic demodulation means. The device includes an excitation array, a measurement array and an active rotor array. The active rotor array is coupled to a drive shaft of the rotational rheometer and measured relative to the measurement and excitation arrays. The active rotor array is driven by an electrical signal that is precisely matched to signals detected by the measurement array. By driving the active array with signals sensed by the measurement array, the sensor allows for reduced sensitivity to unwanted signals not in the measurement direction.

Abstract: A sensor for measurement of small-angle or small-displacement position incorporates multiple independent capacitors in a symmetric relationship. The device presents its output as a standard bridge configured differential signal, which can be interpreted and measured using conventional electronic demodulation means. The device includes an excitation array, a measurement array and an active rotor or linear array. The active array is coupled to a moving object and measured relative to the measurement and excitation arrays. The active array may be floating, grounded or driven by an electrical signal. However, driving the active array with signals sensed by the measurement array allows for reduced sensitivity to unwanted signals not in the measurement direction.

Abstract: A system for making extensional measurements on a sample includes an armature, a motor drive shaft, a moveable cylinder, and a fixed cylinder. The motor drive shaft is attached to the armature. The moveable cylinder is mounted on the armature. The sample is stretched between the moveable cylinder and fixed cylinder by the rotation of the moveable cylinder around the axis of the fixed cylinder and rotation of the moveable cylinder about its own axis. The resistance of the sample produces a torque on the moveable cylinder and the fixed cylinder. The torque is measured on the moveable cylinder or on a transducer shaft attached to the fixed cylinder. The system is adaptable to a commercial rotational rheometer.