Installing the detector

Having arranged a home for the detector, we can now consider installing it. Let us assume you have just taken delivery of a new detector  

Unless there is a particular need to measure particularly low energies, it would be wise to keep the plastic cap protecting a berylhum window in place. If working with it removed, it would be wise to post a large notice warning users of the delicacy of the window, the disastrous effects of rupture and the terrible retribution that will be visited on any miserable wretch who has the misfortune to break it. 

The detector is installed and ready to power-up. 1 assume initially that we are dealing with the more common RF or resistive feedback preamplifier and that the electronic system is NIM based. The instructions below are very detailed, intended for when installing a new detector, checking out a detector after repair, or for those wishing to understand more about their detector. On a routine basis, most people would not be as pernickety — switch on and wind it up being more likely  

The TRP delivers a stepped output, rather than a normal pulse output. Within it are inhibit pulse width and reset delay adjustments. These are tuned at the factory to the particular detector (see the manual) and do not need attention from the user. This type of preamplifier does not have a high count rate LED, because it cannot lock-out. There will be no preamplifier test point and instead of measuring noise, the time between resets (TBR - Section 12.2.2) is monitored. Powering-up does not differ too much from the check-list above, except that  

For a p-type detector, the voltage will move from + 2 V to -2V. 

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The contemporary observation of the full sky with at least two neutrino telescopes in opposite Earth Hemispheres is an important issue for the study of transient phenomena. Moreover v events detection from the Northern Hemisphere is required to observe the Galactic Centre region (not seen by ICECUBE), already observed by HESS as an intense TeV gamma source. In the Norther Hemisphere a favourable region is offered by the Mediterranean Sea, where several abyssal sites (> 3000 m) close to the coast are present and where it is possible to install the detector near scientific and industrial infrastructures. 

We know that all our building materials contain small amounts of uranium, thorium and potassium - all are radioactive to a small degree. Although we will have to provide shielding for our detector in any case, if we are intent on measuring low activity samples it will make sense to install the detector(s) in the centre of the counting room, rather than the more convenient arrangement around the walls. 

Chapter 11, Section 11.2.1 mentioned installing the detector on an anti-vibration support. This simple action... 

Radiation-Density Gauges Gamma radiation may be used to measure the density of material inside a pipe or process vessel. The equipment is basically the same as for level measurement, except that here the pipe or vessel must be filled over the effective, irradiated sample volume. The source is mounted on one side of the pipe or vessel and the detector on the other side with appropriate safety radiation shielding surrounding the installation. Cesium 137 is used as the radi-... 

At least six detectors are built within the machine, suitably distributed around the circumference and placed between the layers along the length of the core where the highest temperature is likely to occur. Each detector is installed in intimate contact with the surface, whose temperature is to be measured and in such a way that the detector is effectively protected from contact with the cooling air. A detector embedded beneath the winding layer inside the slot is of little consequence for it will detect the temperature of the core and not of the winding. The location of the detectors must be as follows ... 

Ideally, an observatory would install perfect detectors in the focal plane of its instruments. What makes a perfect detector The attributes of an ideal detector and the performance achieved by today s technology are given in Table 1. Optical and infrared detectors are nearly ideal in several ways ... 

Once closed inside its copper frame, the array was mounted and thermally connected to the mixing chamber of the Oxford DR installed in Hall A of the underground Gran Sasso National Laboratory. The tower was mechanically decoupled from the cryostat in order to avoid vibrations induced by pumps on the detectors and preamplifiers [98],... 

Careful attention must be paid to ensuring that the correct type of radiation detectors are used and that they are as close as possible to the potential hazard, with nothing blocking their line of sight. Proper installation and design of the detector system includes careful attention to each of the following items ... 

The minimum installation distance between the detector which activates the isolation system and the isolation system itself depends essentially on... 

Operation of detectors with their associated alarm panels should be checked and calibrated after installation. Detector performance can be impaired in a hostile environment by blockages to the detector (i.e., ice, salt crystals, wind blown particles, water or even fire fighting foam, or by inhibition of the catalysts by airborne contaminants such as compounds of silicon, phosphorus, chlorine or lead. It is essential that detectors and alarm panels be checked and re-calibrated on a routine basis. 

Detectors should be calibrated after installation as recommended by the manufacture, typically this is every 90 days. However if experience indicates that the detectors are either in calibration or out of calibration the period of re-examination should be lengthen or shorten accordingly. 

Recognizing that nuclear materials are widely available and the terrorists interests in radiological and nuclear devices, the United States Congress appropriated 300 million to the Department of Homeland Security to install radiation detectors at U.S. borders. Through 2005, DHS had installed 470 radiation portal monitors throughout the country including mail facilities and land and sea entries into the United States. The U.S. has also supported the installation of detectors at the borders of the states of the former Soviet Union through its Departments of State,... 

When specified for equipment with hydrodynamic bearings, provision shall be made for mounting two radial vibration probes in each bearing housing, two axial position probes at the thrust end of each machine, and a one event per revolution probe in each machine. The purchaser will specify whether the vendor is to supply these detectors. The detectors and their mounting and calibration shall be supplied, installed, and tested in accordance with API Standard 670. 

The use of in-line filters between injectors and colunm can prevent the accumulation of particulate material on the inlet frit of an analytical column, and can avoid back-pressure problems. A second, and often overlooked, site for filter installation is between the column and the detector. Cartridge-type filtration-units that contain readily changed, 0.2-/i,m filters are commercially available, and they contribute insignificantly to peak broadening. These filters are essential for the prevention of clogged detectors when laboratory-packed columns are used. 

Combustible gas detectors—where a flammable vapor or gas hazard exists, gas detectors are typically installed. Gas detectors should be arranged to a low set point to sound an alarm and the upper set point to activate the water spray or deluge system. 

Most of the traditional HPLC detectors can be applied to LCxLC analyses the choice of the detectors used in comprehensive HPLC setup depends above all on the nature of the analyzed compounds and the LC mode used. Usually, only one detector is installed after the second-dimension column, while monitoring of the first-dimension separation can be performed during the optimization of the method. Detectors for microHPLC can be necessary if microbore columns are used. Operating the second dimension in fast mode results in narrow peaks, which require fast detectors that permit a high data acquisition rate to ensure a proper reconstruction of the second-dimension chromatograms. 

Procedure. Install the prepared column into the gas chromatograph but do not connect the column to the detector inlet. Condition the column for at least 4 hours by heating at 302°F (150°C) with the earner gas (helium) flow set at. approximately 50 milli-... 

The pressure restrictor that controls the pressure in the column is installed before or after the detector, depending on its type (before for an FID, after for a UV detector). 

Collection of a spectrum relies on the ability of the detector to recognise the energy of each of the emitted photons. This particular detector, installed close to the sample to collect part of the X-ray fluorescence, is either a proportional gas counter (neon)... 

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