Introduction After selecting or designing a heat sink based upon a given air velocity orvolumetric flow rate through the fins, the thermal designer needs to determinethe total amount of flow which must be delivered in the duct or card passagecontaining the module w with heat sink. As shown in Figure 1, some of the flowwill go around or bypass the heat sink. In fact, depending … [Read more...]
Temperature measurement using optical fibers
Introduction Fiber optic temperature measurement has been in use for decades1.The most prevalent methods are fluorescent and radiation thermometry, also knownas pyrometry. Fluorescent temperature measurement is used for lower-rangemeasurements from -200°C to +450°C. Pyrometry best covers ranges from100°C to 4,000°C, and is based on the physics of Planck's blackbodyradiation … [Read more...]
Technical Data
In many cases, especially in the earliest phases of the product creation process, it may be necessary for the Designer to make rough calculations as to the thermal behavior of the proposed product. If a problem is identified, alternative cooling technologies should be considered in the next design phase. In such cases, it is useful to have some idea of the limits of the … [Read more...]
Notes on Using Thermocouples
Introduction Thermocouples are the most widely used temperature sensor in test anddevelopment work. Accurate temperature measurements can be made at low costwith shop-built probes and ordinary low-level voltmeters. What Are Thermocouples and How Do They Work? Any two wires of different materials can be used as a thermocouple ifconnected together as in Figure 1. The AB … [Read more...]
Microthermal imaging in the infrared
John McDonald, Latigo Optics and Grant Albright EDO/Barnes Engineering Division Introduction Infrared imaging methods provide unequaled ease and flexibility forinvestigating micro-circuit temperatures. The researcher need only slide thecircuit under the objective lens and power it up in order to measure thetemperatures throughout the micro-circuit at once, precisely and … [Read more...]
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