Work Bench Components

The general layout of work benches, including hoods, was described in Chapter 2. Now comes the decision about where there should be drawers, cupboards, or other features. Small, shallow drawers, for instance, are just right for storing hydrometers and similar pieces of equipment and should be close to where these are to be used. Burets also need shallow drawers, but they must be wide. Certain pieces of glassware need fairly deep drawers. Much equipment calls for cupboards of certain sizes. 

Catalog in hand, the laboratory planner places units containing drawers and cupboards where they should go. The plan should be marked off with the catalog numbers and will later be given to the cabinet supplier. Some suppliers offer planning kits to make the job easier. 

A work bench rarely consists of a solid bank of cabinets. So-called knee-holes are placed in appropriate locations for sit-down work. Stools can be stored in them when not in use. They are also good for keeping waste containers out of the traffic pattern. 

In one laboratory, an atomic absorbtion instrument was placed on top of a three-foot knee-hole. Drainage from the instrument s atomizer went into a bottle underneath. Data from this instrument was recorded on a strip chart recorder placed on a typewriter stand. When in use, the recorder was at the operator s right, where it was easy to observe and adjust. WTien not in use, it was kept out of the way in the knee-hole, along with the operator s stool. 

In another laboratory, a vacuum pump was installed on a shelf buUt into a two-foot knee-hole well above the floor level. It was out of the way, off the floor, and easy to service. Noise was substantially reduced by attaching rubber stoppers to the pump s base plate as vibration absorbers. Connection to equipment was through a hole in the work top. 

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It may well be a Japanese custom to sit on the floor to assemble shells, but it is rational, for it is possible to arrange all the components and tools around the worker and to avoid the shock caused when things fall on the floor. (But as described later, for shells which require less explosive than V/arimono a working bench is often used in ordinary manufacture.) The operator must take care not to build up a mass of material around the working area. V/hen chlorate compositions are used, have a wet cloth to hand, and wipe the hands with it immediately after handling each composition. Cutting pov/der pasted paper or quick match must be done in another room. 

The spatial assembly or placement instruction of parts and/or materials involved in the step (i.e., how to spatially place a part/component, P, relative to the assembly under construction on the work bench before a fabrication step)... 

Once the above-discussed components of the model have been determined, they are added to the final model of a monolith (or even filter) reactor. The monolith reactor model has already been described in Section III. The next stage is to validate the model by comparing the predictions of the model based on laboratory data, with the real-world data measured on an engine bench or chassis dynamometer. At this stage the reason(s) for any discrepancies between the prediction and experiment need to be determined and, if required, further work on the kinetics done to improve the prediction. This process can take a number of iterations. Model validation is described in more detail in Section IV. D. Once all this has been done the model can be used predictively with confidence. 

This operations sheet can be altered to consider simple assemblies or complicated products, but the approach remains the same. The purpose of estimating is to provide time or cost for the direct labor or material component of the product. The preparation of the operations sheet is important for the finding of part operational costs. Notice that the part cost is the sum of the operational costs, and this fact allows us to concentrate on the importemt steps that are necessary for estimating operations. Once the operational sequence, the selection of the machine, process, or bench, and a basic description of the work have been roughed out, cost estimating begins. 

F igure 9 shows a bench test of the turbine prior to its being mounted to the cryogenic container (of which the turbine is the closer of one end). This setup represents a nonminiaturized unit used in current development work, incorporating, however, airborne structure concepts in all parts. It is noticeable that the expander can be removed or replaced as a compact component by simply removing a few bolts, within a few minutes. 

This immunoassay system was engineered into a laboratory prototype device which includes all system components. The prototype is a compact (20 x 8 x 25 cm), self-standing device and has the potential for complete automation allowing its use in laboratory settings as well as in field conditions. In this work the prototype was used in a bench-top experimental set-up where the bacteria containing sample is fed into the immunoassay system device and the output is recprded on a PC-based data acquisition system. 

Exposure of the sensor layer to the analyte induces a change in its optical properties, which is monitored by a detector such as a photodiode, spectrometer, or CCD camera. The optical signal is then converted into an electrical one for quantification. The sensor layer may be inserted into a bench-top spectrophotometer or, alternatively, the platform components may be partially or completely integrated within a stand-alone miniaturised device. For in situ work the sensor element may be spatially separated from both excitation source and detector, or added as a component to the sample under investigation as in fluorescence microscopy. 

Riveting machine consists of a total of three separate tasks, called Workstations 1, 2 and 3. In Workstations 1 and 2, tasks of assembly components and screw driving are developed in Workstation 2 is also performed the verification of some components of the piece. The cycle time is very short and workers have to perform all tasks in a standing position, with an intensive-local muscular work at the upper limbs. The industrial screwdriver is coupled to the job itself Workstation 3 features three visual tasks in order to check the parts, also featuring the task of verification of its mobility. This task is very repetitive and executed quickly and several times per minute. A visual check of the piece is performed without bench, having the operator to hold the piece manually and turn it to check all the components. The piece... 

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