A closed loop control apparatus utilizes a cooling effect sensor to measure the cooling capacity of a fluid in a supply conduit connected to one or more thermal loads. The sensor includes an electrical heater that is regulated to heat a sampled portion of the cooling fluid at a known rate, and a temperature sensor positioned downstream of the heater to measure the temperature of the heated fluid and thereby determine the cooling effect or capacity of the fluid. A control signal developed by the temperature sensor is fed back to a flow modulating valve that adjusts the flow of cooling fluid to the thermal loads.
A thermocouple rake for measuring the temperature of heated fluids. The thermocouple rake is provided with a cooling chamber for circulating a coolant about individual thermocouple assemblies to cool the assemblies during use in the hot gas. A U-shaped channel is formed downstream in the flow of fluid to accept lead wires from the thermocouple assemblies to deflect the hot gas fluid from contacting the lead wires.
A slip sensor and method of sensing slip for object supporting structure such as a manipulator which includes a pair of relatively movable jaws having opposing jaw faces between which an object may be gripped are shown. At least one thermistor is located at the face of the object supporting structure, which thermistor is intimately engageable with the supported object. The thermistor is maintained at a substantially constant temperature, above ambient temperature, by the passage of current therethrough. The temperature of the gripped object adjacent the thermistor is raised to the above-ambient temperature by heat conduction thereto from the thermistor. With slippage of the gripped object between the jaws, the thermistor is exposed to another portion of the object which is at a different temperature than the temperature of the thermistor whereby the resistance of the thermistor changes. The thermistor is included in a temperature sensing and control unit which maintains the thermistor at a substantially constant temperature, and which has an output related to power supplied to the thermistor to maintain the set-point temperature. The output is digitized and supplied to a digital computer for determining whether or not slippage of the object between the jaws has occurred.
An apparatus and method for measuring coolant quenching rates includes a metallic disk supported on a ceramic tube, the metallic disk including a plurality of thermocouples therein. The metallic disk is heated from above by a torch and coolant is sprayed on the underside of the disk. Changes in temperature throughout the metallic disk are detected by the thermocouples to measure various quenching parameters. The metallic disk may be surrounded by insulating material to maintain heat flow through the disk in a predetermined manner. By heating, insulating and cooling the metallic disk, temperature measurements can be quantified into heat transfer rates to investigate various heat transfer mechanisms and different types of coolants.
A method of infrared thermography is described. The invention utilizes a high resolution infrared thermography system and associated computer in conjunction with a test chamber to determine heat transfer coefficients and film effectiveness values from a single test.
