Complex apparatus

The minute capillary leaks found with a Tesla coil should be plug d with a blob of hot glass the whole joint then needs heating and annealing. When assembhng complex apparatus, parts which will become inaccessible to the flame must be tested for leaks before they are put in their final positions. 

It is occasionally convenient, both when dealing with complex apparatus and when replacing a short section of a fixed glass tube, to be able to glass-blow two joints at once. This can siwcessfully be undertaken when the two joints are reasonably close together and accessible, and when the tubes involved are not larger than 15 mm diameter. 

We think that a long thin blowpipe, as in Figure 83,1, but bent at the end through a greater angle—about 150°—would be very useful for working on complex apparatus. It would enable the back of tubing to be worked from the front. 

Detection and Removal of Leaks and Holes Holes in awkward places are often difficult to find when one is assembling complex apparatus. If the joint in question is put in a luminous flame, or a flame put round the joint, and the apparatus blown into, the air will rush out of the holes and blow the flame away in a blue jet. The hole, when found, can then be repaired with thin glass rod (p. 58) or, if it is very big, it can often be filled in with a piece of glass. When a piece of glass falls out of an apparatus, it can be fused to a rod, to provide a handle, and put back again with the help of thin glass rod. 

ISO 4663 gives no advice as to the relative merits of the three methods it specifies. Method C, which is not strictly a free vibration method, removes the difficulties associated with changing amplitude through the course of the test but at the expense of a rather more complex apparatus. When the inertia member is supported by a torsion wire, as in method B, the tensile strain in the test piece can be controlled to a low level by means of counterweights. 

With the distribution of federal dollars to promote preparedness activities, health departments have purchased and stockpiled personal protective equipment (PPE) for their team members. The ability to quickly locate and properly use the PPE necessary to protect staff when needed is just as important as having access to the department s emergency response plan. For optimum protection, fit testing should be conducted on a regular basis. The nurse must be included in all demonstrations of proper use of personal protective equipment to assure her ability to use more complex apparatus. (See chapter 26 for further discussion.)... 

A potentiostat is inherently a more complex apparatus. It operates with a feedback loop in which the potential between the working and the reference electrodes is compared to an externally set value, the difference is amplified, and a current is passed between the working and counter electrodes, of such magnitude and sign as to make that difference close to zero. 

When using a mantle with complex apparatus such as for distillation (p. 107), support the mantle on a labjack so that it can be removed quickly if overheating occurs (Fig. 5.14). 

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