In-situ sensor

The minienvironment approach to contamination control has been increasing in use. A minienvironment is a localized environment created by an enclosure that isolates the product wafer from contamination and people (48). Another approach is using integrated processing, where consecutive processes are linked in a controlled environment (32). Both requite in situ sensors (qv) to measure internal chamber temperatures, background contamination, gas flow rates, pressure changes, and particularly wafer temperature (4). 

In reviews on the use of in situ sensors" or optical sensor systems" for bioprocesses, UV-vis does not play a major role. An example for the application of at-line UV-vis spectroscopy was presented by Noui et al. The selective flocculation processes of Saccharomyces cerevisiae homogenates were followed with a newly developed direct UV spectrophotometer. The results from a PLS regression model were in good agreement with those from off-line chemical assays. 

V. Vojinovic, J.M.S. Cabral, L.R Fonseca, Real-time bioprocess monitoring. Part I In situ sensors. Sens. Actuators... 

In summary an FDEMS sensor system can be used to monitor the processing properties in situ during the fabrication process of a composite part. A smart sensor control system can be used to monitor resin properties for reproducability-quality assurance, to ensure fabric impregnation, and to control and optimize the composite fabrication process intelligently through in situ sensor feedback. 

For an in situ sensor the residence time for the chemical constituent is defined by the sensing path of the particular technique. In the best possible case this path is the same as for the sonic anemometer, which measures air motion, and hence there is a correspondence when the two factors, c and w, are correlated. 

Successful development and implementation of various chemical sensors for ocean measurements (based on optical, electrochemical, or mass transducers) requires concomitant advances in the design or discovery of organic or inorganic molecules that interact selectively with the important ocean analytes. These developments are particularly important for in situ sensors where no separation of ocean components or addition of external reagents occurs before or during the measurement step. 

The importance of recognition chemistry has been highlighted in several of the previous sections. Developments in recognition chemistry are important for the design of in situ sensors and are a high-priority research area. In practice, the surfaces or membranes of any in situ sensing device will contain chemical soecies that interact selectively and reversibly with... 

Wu Y, Rojas AP, Griffith GW, Skrzypchak AM, Lafayette N, Bartlett RH, Meyerhoff ME. Improving blood compatibility of intravascular oxygen sensors via catalytic decomposition of 5-nitrosothiols to generate nitric oxide in situ. Sensors and Actuators B 2007, 121, 36—46. 

Biosensors are being increasingly used as detectors in FIA systems [284,285, 322, 379, 476]. The drawbacks of biosensors as direct in situ sensors, namely their low dynamic range, their lack of ability to survive sterilization, their limited lifetime, etc. are no longer valid ex situ because the analyzer interfaces the biosensor which can be changed at any time and FIA can provide samples in optimal dilution. The need for chemicals and reagents can be drastically reduced when employing biosensors, specifically when the entire system is miniaturized [48]. 

On-line measurements produced with in situ sensors are difficult to validate. The usual procedure for evaluating the quality of a measurement is restricted to calibration/checking prior to and after a cultivation. A few sensors such as the pC02- or the Cranfield/GBF-glucose sensor [42] allow removal (at least of measuring buffer and also of the transducer itself) and, therefore, recalibration of the transducer during a cultivation (Fig. 23). 

In conventional CMP, end-point detection relies on in situ sensors such as eddy current sensors [26] to measure the remaining copper film thickness. In... 

Nano in-situ sensor and LS-50 liquid sampler are designed for particle measurements in process chemicals and DI water. They are ideal for sampling main process supply lines or point-of-use delivery lines where continuous monitoring of contamination levels is necessary. They can be operated either in-line or batch mode. 

Fig. 8 Crystallization apparatus showing in-situ sensors (FBRM at upper right, PVM at upper left, FTIR spectrometer with ATR probe at left in the background). Antisolvent pump not shown.

The autoanalyzer represented a substantial advance in the ability to make repetitive on-board chemical measurements. The development of flow-injection analysis promises to enlarge enormously the scope and speed of such methods. The flow-injection methods were pioneered in clinical chemistry, and are being developed for oceanography by Kenneth S. Johnson and Robert L. Petty. Dana Kester and Richard W. Zuehlke are also developing new autoanalyzer techniques for the rapid analysis of certain trace metals in seawater. One of the most technologically exciting prospects for the future involves the use of fiber optics to transmit a spectroscopic signal from an in-situ sensor to the ship s deck. 

These analyses, combined with data from in situ sensors, provide information on small-scale and mesoscale features not otherwise available. Signals in the sample stream are modified by passage through the hose. This modification and time delays introduced by analysis must be considered in sampling strategy and data management approaches. This system has been used to determine nutrients, in vivo fluorescence, and temperature in a warm core ring. Examples of the results are provided the fluorescence, temperature, and nitrate distributions show considerable independence. 

Electrical System. The conductors in the hose-cable carry power and control signals down to the underwater vehicle and return information. The drive-pump motor is powered by three-phase, 220 V carried down three paired conductors. The solenoid valve, which controls the clean pump, is energized by 24 V direct current (DC), which is controlled on deck. The submersible pump that circulates water through in situ sensors uses 110 V alternating current (AC) power from the hose-cable. 

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