Unattended system

Pressure-containing systems designed for use at elevated temperatures should have a positive temperature controller. Manual control using a simple variable autotransformer, such as a Variac, is not good practice. The use of both a back-up temperature controller capable of recording temperatures and shutting down an unattended system is strongly recommended. 

The fuel pin assay system (FPAS) is used to determine the Pu-content of fresh MOX fuel pins stored on trays with results that correspond to greater than 2% with the declared data (Cowder and Menlove 1982 Miller et al. 1989). FPAS has a relatively flat response for 1.2 m. The system primarily operates in attended mode by the inspector identifying and checking the positioning of the pin tray in the counter. The system could be transformed to an unattended system using a robotic conveyor for the tray delivery/removal in combination with a radiation-triggered ID camera to record the tray identification. 

Unattended system is any manned, unmanned, mobile, stationary, active, and/ or passive system, with or without power that is designed to not be watched, or lacks accompaniment by a guard, escort, or caretaker. 

A UMS may be mobile or stationary, and includes the vehicle/device and its associated control station. UMSs include, but are not limited to UGVs, UASs, unmanned underwater vehicles, unmanned surface vessels, and unattended systems. Missiles, rockets, submunitions, and artillery are not considered UMSs. 

Important to environmental analysis is the ability to automate the injection, as weU as the identification and quantitation of large numbers of samples. Gc/ms systems having automatic injectors and computerized controllers have this capabiUty, even producing a final report in an unattended manner. Confirmation and quantitation are accompHshed by extracting a specific ion for each of the target compounds. Further confirmation can be obtained by examining the full scan mass spectmm. 

Capability of systems for fully automatic, unattended operation Capability to remove gaseous or vapor contaminants from process streams to extremely low levels... 

A complicated analyser system such as that described above can only be maintained if all of the valve-switching events are scheduled in the correct positions in the chromatogram. Mismatch of one of the events will cause (parts of) components to be directed to the wrong columns and thus possible misidentifications. Therefore, accurate determination and maintenance of the cutting windows are essential. This can only be accomplished in a fully automated system with accurate flow and temperature controls. Once these prerequisites are fulfilled, the system will operate unattended and produce results of high quality. The repeatabilities generally achieved are of the order of 1 % rel. 

Method development remains the most challenging aspect of chiral chromatographic analysis, and the need for rapid method development is particularly acute in the pharmaceutical industry. To complicate matters, even structurally similar compounds may not be resolved under the same chromatographic conditions, or even on the same CSP. Rapid column equilibration in SFC speeds the column screening process, and automated systems accommodating multiple CSPs and modifiers now permit unattended method optimization in SFC [36]. Because more compounds are likely to be resolved with a single set of parameters in SFC than in LC, the analyst stands a greater chance of success on the first try in SFC [37]. The increased resolution obtained in SFC may also reduce the number of columns that must be evaluated to achieve the desired separation. 

System control and data acquisition are done with a personal computer using Paragon software. About 150 input and output modules were used for the two laboratory cells. This is expensive and may seem excessive, but a lot of the inputs and outputs are used for safety purposes so that the cell can operate unattended 24 hr a day, 7 days a week to get good long-term data. 

Optical sensors and relay switches are used throughout the test routine for verification. For all possible problems, as well as the sequence in which they occur, the robot must recognize that there is a problem, define the problem, decide how best to resolve the problem, perform the necessary operations to overcome the problem, and enable the system to resume testing. This is an AI application area and a critical feature, mainly because the system operates unattended and measurements are taken overnight and during weekends. 

Demonstrate that the system performs logout after a configurable interval to end an unattended session. 

A recent development in this context is the Liberty system introduced by CEM in 2004 (see Fig. 3.25). This instrument is an automated microwave peptide synthesizer, equipped with special vessels, applicable for the unattended synthesis of up to 12 peptides employing 25 different amino acids. This tool offers the first commercially available dedicated reaction vessels for carrying out microwave-assisted solid-phase peptide synthesis. At the time of writing, no published work accomplished with this instrument was available. 

The random-access sampler can go to any sample cup position, any number of times, at any time during a run. This abihty to sample cups in any order and to return to sample cups more than once, allows system automation to be greatly extended. It saves time and work by allowing automatic re-run of sample(s) following off-scale peaks and also the automatic dilution and re-analysis of off-scale samples. The sampler also saves cup positions, allowing more samples and longer unattended runs. For example, one set of standards provides initial cahbration, drift correction, carry-over correction and periodic quality control. In addition, samples or standards can be sampled in repHcate form from a single cup. The random-access sampler can be controlled and either the operator or the computer can make the decision as to which cup the sampler must go to. 

For the water analysis, automation is clearly best achieved with an auto-injector for the mechanical handhng of the samples coupled with on-hne data capture, using the computer to analyse the peak data. Serious consideration was given to employing the very considerable in house automation experience to construct a purpose-built auto-injector. However, in the interests of a speedy implementation of the automatic system, it was decided to purchase a commercially available auto-injector and to concentrate the laboratory s efforts on the area of on-hne data capture. Interfacing the complete system assembly via a data communications network required the development of a special control device (commhox), which allowed the LGC hardware to run unattended hut provided an audible warning in event of a fault condition. 

Figure 7.5 depicts the preparative separation of a mixture of cisitrans isomers. A total of 680 injections were made to process 34 g of crude. The system operated unattended for 23 h to produce both isomers with 100% purity. 

---