Laboratory devices

The helium leak detector is a common laboratory device for locating minute leaks in vacuum systems and other gas-tight devices. It is attached to the vacuum system under test a helium stream is played on the suspected leak and any leakage gas is passed into a mass spectrometer focused for the helium-4 peak. The lack of nearby mass peaks simplifies the spectrometer design the low atmospheric background of helium yields high sensitivity helium s inertness ensures safety and its high diffusivity and low adsorption make for fast response. 

Amorphous Silicon. Amorphous alloys made of thin films of hydrogenated siUcon (a-Si H) are an alternative to crystalline siUcon devices. Amorphous siUcon ahoy devices have demonstrated smah-area laboratory device efficiencies above 13%, but a-Si H materials exhibit an inherent dynamic effect cahed the Staebler-Wronski effect in which electron—hole recombination, via photogeneration or junction currents, creates electricahy active defects that reduce the light-to-electricity efficiency of a-Si H devices. Quasi-steady-state efficiencies are typicahy reached outdoors after a few weeks of exposure as photoinduced defect generation is balanced by thermally activated defect annihilation. Commercial single-junction devices have initial efficiencies of ca 7.5%, photoinduced losses of ca 20 rel %, and stabilized efficiencies of ca 6%. These stabilized efficiencies are approximately half those of commercial crystalline shicon PV modules. In the future, initial module efficiencies up to 12.5% and photoinduced losses of ca 10 rel % are projected, suggesting stabilized module aperture-area efficiencies above 11%. 

Copper Indium Diselenide. CuInSe2 (CIS) has proven to be one of the most promising thin-film photovoltaic materials. CIS ahoy materials have yielded smah-area (ca 1 cm ) laboratory devices with efficiencies in excess of 17% and large-area (ca 0.5 m ) monolithic integrated modules with efficiencies in excess of 11%, and have shown excehent radiation hardness. 

Division of Clinical Laboratory Devices Food and Drug Administration Rockville, Maryland... 

The Safe Medical Devices Act of 1990, a major revision to the 1976 amendments, among other revised requirements provided two major mechanisms for bringing an IVD medical device to market premarket notification and premarket approval. The act is administered by the FDA s Center for Devices and Radiological Health, of which the Division of Clinical Laboratory Devices (DCLD) is a part. The premarket notification process is used for devices that can be classified... 

A confined explosion occurs in a confined space, such as a vessel or a building. The two most common confined explosion scenarios involve explosive vapors and explosive dusts. Empirical studies have shown that the nature of the explosion is a function of several experimentally determined characteristics. These characteristics depend on the explosive material used and include flammability or explosive limits, the rate of pressure rise after the flammable mixture is ignited, and the maximum pressure after ignition. These characteristics are determined using two similar laboratory devices, shown in Figures 6-14 and 6-17. 

The RSST (reactive system screening tool) is a laboratory device used to characterize the reactive nature of liquid materials. It is essentially an adiabatic calorimeter, with the test sample heated at a constant temperature rate until an exothermic reaction is encountered. 

A common laboratory device is a batch reactor, a nonflow type of reactor. As such, it is a closed vessel, and may be rigid (i.e., of constant volume) as well. Sample-taking or continuous monitoring may be used an alternative to the former is to divide the reacting system into several portions (aliquots), and then to analyze the aliquots at different times. Regardless of which of these sampling methods is used, the rate is determined indirectly from the property measured as a function of time. In Chapter 3, various ways of converting these direct measurements of a property into measures of rate are discussed in connection with the development of the rate law. 

Mel-Temp Millipore Swagelok Teflon Laboratory Devices, Cambridge, Massachusetts Millipore Corporation, Bedford, Massachusetts Crawford Fitting Company, Solon, Ohio E.I. DuPont de Nemours Company, Wilmington, Delaware... 

Laboratory devices, gas-liquid mass transfer, 15 690-692 Laboratory extractors, 10 768 Laboratory flocculant testing, 11 638-639... 

A DIGI-BLOCKt Jr. heating block (Laboratory Devices, USA, Inc.) that was fitted to a IKA-Schuttler-MTS-2 orbital... 

Equipment. All melting points were determined with a Mel-Temp apparatus from Laboratory Devices and are uncorrected. Gas chromatography was carried out on either a Varian Aerograph 700 or Hewlett-Packard 5880 chromatograph. Beckman IR-9 and Perkin Elmer FT-1800 spectrophotometers were used for the determination of mid-IR spectra. All NMR spectra were obtained using an IBM NR-80 FT spectrometer. Elemental analyses were determined for all new monomers and polymers by Micro-Tech Laboratories, Inc. of Skokie,... 

Tag closed-cup tester analy chem A laboratory device used to determine the flash point of mobile petroleum liquids flashing below 175°F (79.4°C). Also known as Tagliabue closed tester. tag klozd k3p tes-tor tagged molecule chem A molecule having one or more atoms which are either... 

The mastication equipment most commonly employed is standard rubber instrumentation such as roll mills, internal mixers, extruders or laboratory devices modeled on them (e.g., a single-rotor internal masticator described by Wilson and Watson (43), die model improved by Kargin and coworkers (11) and the Brabender plastograph). 

Let us assume that we have a geometrically similar laboratory device of D = 0.4m (F 0.050 m ) with a turbine stirrer of rotational speed of the stirrer is n = 750/min. Which must the gas throughput be to obtain Q = idem in the laboratory device The answer is... 

A laboratory device used to connect the oxidation and reduction half-cells, which usually comes in two types glass tube or filter paper. 

Columns of this design have had wide acceptance as useful laboratory devices and are available in small sizes (1-in. diameter) which are capable of producing values of HETS in the neighborhood of 2 to 3 in. They are consequently frequently used for process evaluation where only small amounts of materials may be available. As a result, there have been a... 

There are many laboratory devices available for the reduction of the primary sample to an analysis sample. The three most important methods used in the pharmaceutical industry are (i) scoop sampling, (ii) cone and quartering, and (iii) the spinning riffler or rotary sample divider (Fig. A-3). 

The Premixed, Laminar Flame Perhaps the most common laboratory device for studying combustion chemistry is the laminar, one-dimensional, premixed flame [275]. Such flames are normally stabilized on top of a porous metal cylinder through which the reactants are fed. The flame is usually operated at low pressure, normally between 10 and 100 Torr, to spread out the reaction zone so that spatial distributions of temperature and... 

The melting point is determined conveniently with a Mel-Temp apparatus and a 90-510° thermometer designed for use with it (Laboratory Devices, Post Office Box 68, Cambridge 39, Massachusetts). An evacuated capillary containing a sample is... 

Figure 8. A simple laboratory device for measuring peel strength.

When varying the temperature of the catalyst, while keeping all other variables constant, it was noticed in laboratory devices (30), burning iso-octane containing TEL, that the retention of lead on monolithic catalysts does increase with temperature (10) in the 350°-760°C range. In burner experiments with monolithic base metal catalysts (21) lead retention doubled when the temperature was increased from 600° to 850°C. In dynamometer studies of pelleted catalysts, again, a temperature increase from 550° to 750°C caused a sevenfold increase in lead retention (23). 

Testing Requirements of Peroxidizable Compounds Tests for the Presence of Peroxides Characteristics of Chemical-Resistant Materials Selection of Protective Laboratory Garments Protective Clothing Levels Selection of Laboratory Gloves Selection of Respirator Cartridges and Filters Effects of Electrical Current on the Human Body Electrical Requirements of Common Laboratory Devices... 

The following table lists some common laboratory devices along with the current and power requirements for the operation of the device.1 This information is important to consider when instrumentation is being installed, relocated, or used on the same circuit. Common 120-V circuits in laboratories are typically rated at 10 or 15 A. Note that the current draw often spikes to a high level in first few microseconds after a device is energized. This is especially true for devices that have electric motors. 

Plug and Outlet Conhgurations for Common Laboratory Devices... 

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