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Precision high temperature sensors often require temperature compensation. Quartzdyne pressure transducers use a temperature sensitive quartz crystal for compensation. In an effort to shrink transducer packaging, and increase reliability; a prototype frequency output temperature sensor was designed using a 0.8um silicon bulk CMOS process. The 250°C operational sensor is based on a PTAT current generator. The design uses high temperature design techniques that were proven reliable in prior Quartzdyne ASIC's. The output frequency is 34kHz at 30°C, with a sensitivity of 100Hz/°C and achievable accuracy of ±0.3°C from 25°C to 200°C. This paper will review the sensor's characteristics, including the output linearity, hysteresis, accelerated aging and temperature cycling to demonstrate the performance and long term reliability and repeatability of the sensor.

In order to improve the reliability of down-hole electronics Quartzdyne Electronics has invested over 10 million device test hours in life testing of our circuits in both powered and un-powered modes. In addition to time at temperature, these tests include thermal cycling and high impact drop testing. While resistors tend to be generally reliable, we have observed resistance drift in some units that has pushed circuit performance outside of accepted electrical specifications. In an attempt to comprehend the root cause(s) of resistance drift, failed samples have been studied in a scanning electron microscope. The resulting observations have led to structured designs of experiment to isolate the many possible root causes. This paper will present these observations, experimental outcomes and draw conclusions surrounding thick film vs. thin film performance, variations between value ranges, differences between vendors, and a possible link relating the drift mechanism to the method and extent of value trimming. This information should be useful to resistor vendors interested in improving the quality and performance of their products.

There is a need for stable test standards for many remote sensing applications that can be used both in the laboratory and in rugged test environments. Ideally these standards would be stable over time such that the same standard could be used from year to year for comparison of system performance. While ink-jet and spray gun methods can disperse controlled doses of dissolved analytes, methods to maintain particle size spectral variations are lacking. In addition, standards that are environmentally robust and stable over time are limited. As part of the recent Lighthouse work toward a Hyperspectral Imagery (HSI) proximal handheld sensor, Special Technologies Laboratory (STL) was tasked to do preliminary work toward a rugged, transportable, waterproof target board. This involved developing test standards using minerals of known particle sizes that have spectrally relevant features. Mineral powders were dispersed in binders that did not change their spectral characteristics. These standards were packaged such that they could be transported and used repeatedly. This paper discusses the methodology for developing this preliminary set of targets. Target sizes were limited to the proximal case, and further work is required to finalize the optimum binder and examine other possible appropriate minerals.

This paper presents structural and thermal modeling of a high-performance CCD camera designed to operate under severe environments. Minimizing the dark current noise required the CCD to be maintained at low temperature while the camera operated in a 70 degrees C environment. A thermoelectric cooler (TEC) was selected due to its simplicity, and relatively low cost. Minimizing the thermal parasitic loads due to conduction and convection, and maximizing the heat sink performance was critical in this design. The critical structural features of this camera are the CCD leads and the bond joint that holds the CCD in alignment relative to the lens. The CCD leads are susceptible to fatigue failure when subjected to random vibrations for an extended period of time. This paper outlines the methods used to model and analyze the CCD leads for fatigue, the supportive vibration testing performed and the steps taken to correct for structural inadequacies found in the original design. The key results of all this thermal and structural modeling and testing are presented.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Chronic pain syndromes are well known to the medical community. The incidence of chronic pain syndromes and cost of evaluating these patients are rapidly increasing. Chronic testicular pain is a fairly common manifestation of a chronic pain syndrome. Retrospectively, we reviewed the records of 48 patients with chronic testicular or scrotal pain (greater than 6 months) evaluated at our institution during the last 7 years. These patients had multiple diagnostic and interventional procedures with few positive findings. There was little improvement in these patients after multiple surgical procedures. Based on the paucity of objective clinical findings a carefully directed diagnostic evaluation for orchialgia is outlined. The treatment of these patients is best managed by a multidisciplinary approach involving the urologist and a pain clinic environment. We believe that extensive diagnostic testing is not indicated in the absence of clinical findings and may serve to worsen the condition or lead to iatrogenic injury. Surgical intervention should be limited to cases when a clear indication is present.