Monitoring instrumentation

The "Plant Life Assessment Network" (PLAN), was started on the 1/12/1997, established around EU funded research projects working in the area of inspection, instrumentation, monitoring, structural mechanics and maintenance. 

Instruments are provided to monitor the key process variables during plant operation. They may be incorporated in automatic control loops, or used for the manual monitoring of the process operation. They may also be part of an automatic computer data logging system. Instruments monitoring critical process variables will be fitted with automatic alarms to alert the operators to critical and hazardous situations. 

Most HPLC instruments monitor sample elution via ultraviolet (UV) light absorption, so the technique is most useful for molecules that absorb UV. Pure amino acids generally do not absorb UV therefore, they normally must be chemically derivatized (structurally altered) before HPLC analysis is possible. The need to derivatize increases the complexity of the methods. Examples of derivatizing agents include o-phthaldehyde, dansyl chloride, and phenylisothiocyanate. Peptides, proteins, amino acids cleaved from polypeptide chains, nucleotides, and nucleic acid fragments all absorb UV, so derivatization is not required for these molecules. 

The lower instruments monitors a closed container sealed off at time zero. The blue and the yellow instruments show the same concentrations from time zero until the yellow instruments reaches the end of the catalyst bed, illustrating the equivalence between flow... 

Instrumental monitoring of the gaseous components of indoor air or indoor air samples has become routine in environmental analysis. In all monitoring systems, a number of characteristics are considered essential. Among these are instrumen-... 

Linnett and various co-workers [57, 58] also observed oscillatory glow, somewhat intermittently, in their studies of the reaction with extensively-dried reactants (see above) in vessels with untreated surfaces. These authors unfortunately used the phrase multiple explosions to describe the phenomenon which they observed only by eye. Later, meticulous work exploiting instrumental monitoring of the reaction by Bond et al. [59, 60] revealed that the ignition limit reported by the Linnett group on the basis of a detectable emission actually corresponds to the limit for steady glow. 

Highly accelerated moisture tests (HAST) were performed in a two-zone Hirayama pressure chamber in which samples were exposed to 145°C, 85% R.H. and 18V bias. Periodically, the devices were removed from the pressure chamber and the linear devices were tested for electrical performance in a Gen Rad 1731M Linear IC Test System. This instrument monitors several device parameters. All of these parameters remained within specifications until the devices failed due to open circuitry resulting from corrosion. Earlier tests were performed at 131°C, 85% R.H. and 30V bias (2). Under these conditions the test requires long times. Short test times are readily achieved at 145°C (6). 

Laconti AB Giner, Inc., Waltham, Massachusetts Development of a solid-state electrochemical sensor that is based on ionomer membrane technology for instrument monitoring where ammonia gas may have negative impacts. SBIR... 

Gas monitoring systems should be chosen to suit their intended use since significant differences exist between available sensing technologies, price, and performance. There are basically two types of gas detection technologies. With instrumentation monitors, a sample of air is drawn through a piece of tubing, the sample draw line, to an analysis instrument, which is most commonly based on mass spectrometry, flame emission spectrometry, infrared spectrometry, or colorimetric (paper tape) response. 

The Brookfield DV-II+-series rotational viscometers and DV-IIl-series rheometers have a built-in Time-to-Torque feature. The selected instrument is run in stand-alone mode, at one constant speed with one spindle. The motor rotation automatically stops at a user-selected torque reading that is a percent of full-scale range or "FSR." The elapsed time and the setpoint torque are then shown on the instrument s display. This system can therefore be used as a type of gel timer - the instrument monitors the torque increase to 90 % of full-scale range, for example, as the sample s viscosity increases during gelation. However, it is a "one-point" test - that is, only one data point is acquired. If the instrument s "continuous printing" mode is selected and a... 

Some instruments monitor the concentration of particles in the beam by means of an obscuration detector located at the focal point of the lens. If no particles are present in the beam, all the light falls on the obscuration detector. As soon as particles enter the beam, they hIcKk some of the light and scatter light onto the elements of the detector array. The fraction of the light attenuated by scattering, absorption, or both is related to the concentration of particles in the beam (see Section 34D). 

Corrosion rates and distribution cannot always be predicted. But in many cases it is important to be aware of the state at any time in order to avoid unforeseen failures and to take or adjust necessary protective measures. Systems that require monitoring are often more or less inaccessible for visual inspection, and therefore various equipment and methods for instrumented monitoring have been developed. A benefit of these methods is that quantitative results are usually obtained, whieh indieate eorrosion rate and/or degree of protection, development of the state with time ete. Some monitoring methods are dealt with in the next sections. 

Reactor confinement facilities vere Installed to control the release of radioactive material from the reactor building in the event of a nuclear incident. The instrumentation monitors the pressure and air balance in various sections of the building and the radiation level and spectrum of the air exhaust. 

Required Modification of Instrumentation Monitoring the Temperature of the Rotor... 

Regular instrumental monitoring of airborne concentrations is not usually justified or practical in laboratories but may be appropriate when testing or redesigning hoods or other ventilation devices (12) or when a highly toxic substance is stored or used regularly (e.g., 3 times/week) (13). 

SIA instrumentation has been applied to the automated dissolution studies of a sustained release formulation of ibuprofen. The instrument monitored the absorbance of seven replicate samples six times per hour. With the application of partial least squares regression analysis to the resultant absorbance data, this same instrumentation was capable of the simultaneous determination of aspirin, phenacetin, and caffeine in pharmaceutical formulations. 

Secure Landfills Secure landfills for hazardous waste must meet stringent standards of the EPA. A secure landfill must have an impervious clay base or an artificial liner. These features intend to contain any leachate. A drainage system around the landfill collects groundwater and prevents it from entering the landfill. Special designs and instrumentation monitor the drainage system and groundwater near and under the landfill for leachate. 

---