Abstract: A variable capacitance fluid pressure sensor of the type which includes a deflectable member includes a contaminant exclusion system which protects the deflectable member from both solid and non-solid fluid-borne contaminants. A system of traps disposed between the fluid inlet to the sensor and the deflectable member prevents deposition of process vapors in the fluid on the deflectable member and collects a variety of sizes of fluid-borne solid contaminants remote from the deflectable member.

Abstract: A capillary rheometer apparatus includes a housing, a plunger, the housing having a reservoir for receiving the plunger in a polymer melt, and a mechanism for blocking flow of the melt out of the reservoir. A driving mechanism is included for driving the plunger longitudinally within the reservoir to move one end of the plunger in contact with the melt. A diaphragm, which is coupled to the one end of the plunger, deflects in response to melt pressure in the reservoir. A mechanism, responsive to diaphragm deflection, determines pressure of the melt. Another mechanism is included for determining the temperature of the melt and a further mechanism is included for indicating longitudinal movement of the plunger. From such determinations, the PVT characteristics and the apparent shear viscosity characteristics of the polymer melt can be obtained.

Abstract: An optical pressure transducer includes a body for supporting therein both an input optical fiber and an output optical fiber. A light source generates input light to the input optical fiber. A force responsive diaphragm is secured to the body and deflects in response to sensed pressure. A fixed reflector and a moveable reflector, which is attached to and moves with the diaphragm, are disposed in the optical path between the input and output optical fibers and reflect at least a portion of the input light from the input optical fiber to the output optical fiber. The amount of light reflected depends upon the deflection of the diaphragm. A system for monitoring and controlling the light source, including an optical detector in a feedback arrangement, is provided such that the amount of light generated by the light source remains constant and maximized.

Abstract: A capillary rheometer apparatus includes a housing, a plunger, the housing having a reservoir for receiving the plunger in a polymer melt, and a mechanism for blocking flow of the melt out of the reservoir. A driving mechanism is included for driving the plunger longitudinally within the reservoir to move one end of the plunger in contact with the melt. A diaphragm, which is coupled to the one end of the plunger, deflects in response to melt pressure in the reservoir. A mechanism, responsive to diaphragm deflection, determines pressure of the melt. Another mechanism is included for determining the temperature of the melt and a further mechanism is included for indicating longitudinal movement of the plunger. From such determinations, the PVT characteristics and the apparent shear viscosity characteristics of the polymer melt can be obtained.

Abstract: An optical pressure transducer includes a body for supporting therein both an input optical fiber and an output optical fiber. A light source generates input light to the input optical fiber. A force responsive diaphragm is secured to the body and deflects in response to sensed pressure. A fixed reflector and a moveable reflector, which is attached to and moves with the diaphragm, are disposed in the optical path between the input and output optical fibers and reflect at least a portion of the input light from the input optical fiber to the output optical fiber. The amount of light reflected depends upon the deflection of the diaphragm. A system for monitoring and controlling the light source, including an optical detector in a feedback arrangement, is provided such that the amount of light generated by the light source remains constant and maximized.

Abstract: A capillary rheometer plunger having a liquid-filled capillary passage extending within the plunger is removably housed in a heater block holder for maintaining temperature stability and minimizing temperature induced errors. The plunger is placed in the holder during purging, cleaning, reloading and packing the capillary rheometer with the polymer under test. The holder includes an electrically heated holder member disposed within an aperture of an outer shield and is provided with an aperture in which the plunger is removably received for heating. A base supports the shell. A temperature sensor disposed in the shell controls the temperature of the holder member at the temperature of the polymer under test.

Abstract: A capillary rheometer including a plunger pressure transducer assembly which contains a liquid metal fill capillary passage therein. When the plunger is urged downward onto the melted polymer, a diaphragm at the end of the plunger senses the pressure within the melted polymer and transmits this pressure to the liquid metal fill. An additional diaphragm disposed in the opposite end of the plunger pressure transducer assembly senses this transmitted pressure within the liquid metal fill for an accurate indication of the pressure therein.

Abstract: An optical pressure transducer employing input and output optical fibers defining therebetween an optical path. The optical path is interrupted by a fixed reflector and a moveable reflector. The moveable reflector is secured by adjustment means to the diaphragm that is responsive to pressure being measured.

Abstract: Input force transmitted from a monitored process variable is applied against a displaceable double beam mechanism being opposed by a dual spring bias presettable individually to the separate set points of the switch. Comprising the double beam mechanism is an equalizer beam underlying a pair of scissor beams such that displacement force incurred by the equalizer beam is conducted through the scissor beams and supported push rods to operate the switch actuators. In a hi/lo set point embodiment two switches are separately actuated in a predetermined sequence while in a deadband embodiment a single switch is independently settable for make and break.