Shutter

Inertial collectors. In inertial collectors, an object is placed in the path of the gas. An example is shown in Fig. 11.1. While the gas passes around the shutters, particles with sufficiently high inertia impinge on them and are removed from the stream. Only particles in excess of 50/um can reasonably be removed. Like gravity settlers, inertial collectors are widely used as prefilters. 

Figure 3 gives a view of a bucket on the rotation table in front of the shutter of the image intensifier. 

When a block is inside, the entrance panel is closed and the inspection is ready to start. The inside of the stainless steel X-ray tubehead housing is clad in lead with an on/ofT shutter in front of a thin plastic X-ray window. The thin window is to ensure the IP 65 classification. The window is of plastic that is not affected by the cleaning agents. The on/off shutter is interlocked with the entrance and exit panels so X-rays can be kept on at all times without risk of radiation leakage or exposure of the frozen fish blocks prior to the actual inspection. 

In order to minimize the radiation dose, the inspection time is limited to 30 seconds of exposure (programmable) after which the X-ray on/off shutter will shutter off the X-rays and the block must be unloaded. A timer will keep the operator informed of the time that has elapsed. 

Within the preset time limit, the operator can at any time press the reject button, which will close the on/off shutter, open the exit panel and move the block on to an output conveyor At the same time the entrance panel will open to admit the next block awaiting inspection. 

Figure Bl.27.7. Schematic diagram of isothennal displacement calorimeter A, glass calorimeter cell B, sealed heater C, stainless steel stirrer D, thennistor E, inlet tube F, valve G, window shutters Ft, silver rod ...

For the sake of illustration, a TOF analyzer could be likened to a camera taking snapshots of the m/z values of an assembly (beam) of ions the faster the repetition rate at which the camera shutter is clicked, the greater is the number of mass spectra that can be taken in a very short time. For TOF analyzers, it is not uncommon to measure several thousand mass spectra in one second All such spectra can be added to each other digitally, a process that improves the signal-to-noise ratio in the final accumulated total. 

In plasma chromatography, molecular ions of the heavy organic material to be analy2ed are produced in an ionizer and pass by means of a shutter electrode into a drift region. The velocity of drift through an inert gas at approximately 101 kPa (1 atm) under the influence of an appHed electric field depends on the molecular weight of the sample. The various sonic species are separated and collected every few milliseconds on an electrode. The technique has been employed for studying upper atmosphere ion molecule reactions and for chemical analysis (100). 

Radiation safety enclosure X-ray shutter and attenuator assembly... 

Step 2. The computer opens a shutter, bathing the crystal in a monochromatic x-ray beam. The computer rotates the crystal for about one minute and the rotation diffraction image is stored on the detector and then read into the computer memory. When the operator examines the image and is confident that the sample is indeed a single crystal, the experiment can proceed. 

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