Electric analyzer schematic

The primary reference method used for measuring carbon monoxide in the United States is based on nondispersive infrared (NDIR) photometry (1, 2). The principle involved is the preferential absorption of infrared radiation by carbon monoxide. Figure 14-1 is a schematic representation of an NDIR analyzer. The analyzer has a hot filament source of infrared radiation, a chopper, a sample cell, reference cell, and a detector. The reference cell is filled with a non-infrared-absorbing gas, and the sample cell is continuously flushed with ambient air containing an unknown amount of CO. The detector cell is divided into two compartments by a flexible membrane, with each compartment filled with CO. Movement of the membrane causes a change in electrical capacitance in a control circuit whose signal is processed and fed to a recorder. 

This diffusion chamber was modified to provide a uniform flow from two channels at the entrance, one for the filtered room air and the other for the gas from the radon chamber. This modified mobility analyzer is schematically shown in Figure 2. The pressure heads are adjusted so that the gas velocities, v, are the same in both channels. An adjustable vertical electric field, E, is provided through the analyzer so that charged particles are drawn toward the detector located at x cm from the entrance. With the known distance, d, between the radon-laden gas channel and the detector implanted plate, the mobility can then be determined from... 

Figure 3. Schematic of electrical circuit for cotton dust analyzer.

In a time-of-flight (TOF) analyzer the time of flight of ions between the ion source and the detector is measured [61]. This requires that the time at which the ions leave the ion source is well-defined. Therefore, ions are either formed by a pulsed ionization method or various kinds of rapid electric field switching. The single discontinuous laser pulses at distinct time points used in MALDI can be ideally combined with time-of-flight mass separation. TOF analyzers thus received increasing interest with the development of MALDI MS. The schematic draw of a linear MALDI-TOF MS is shown in Fig. (9). 

FIGURE 11.65 (a) Electrical aerosol analyzer (adapted from Whitby and Clark, 1966). (b) Schematic diagram of differential mobility analyzer (adapted from Yeh, f993). 

Application of a potential between reservoirs 1 (sample) and 4 (injection waste) electrokinetically pumps sample solution as indicated in Fig. 3. In this way, a geometrically defined 150 pm (90 pi) section of the separation channel can be filled [19]. If the injection potential is applied long enough to ensure that even the slowest sample component has completely filled the injection volume, a representative aliquot of sample can be analyzed (so-called volume defined injection). This is in contrast to electrokinetic sample injection in conventional capillaries, which is known to bias the sample according to the respective ionic mobilities [61]. These characteristic differences are shown schematically in Fig. 4. It should be noted that this picoliter sample injector is exclusively controlled by the application of electric fields and does not require any active elements with moving parts such as valves and external pumps. The reproducibility of the peak height of the injected sample plugs has been reported to be within 2 % RSD (relative standard deviation) and less [19,23]. 

FIGURE 7.36 Schematic of the PMMA chip electrospray arrays used to analyze sequentially eight samples (A, copper electrode B, acrylic bar C, electrical cable D, plastic box E, spring on an acrylic rod). The insets show the dimensions of the chip and the close-up view of a channel [781]. Reprinted with permission from the American Chemical Society. 

Figure 1. Schematic diagrams of TEB and LLS instrumentation. P, pinholes L, lenses B, polarizers C, cell Q, quarter wave plate PMT, photomultiplier tube HVG, high voltage generator MP, microprocessor TR, transient recorder CL, correlator CT, counter 6, scattering angle. For the TEB setup polarizers B-, B2 have polarization axis oriented at tt/4 with respect to the x-axis, as shown in (a). After the light beam passed through the cell with electric field in the x-direction containing a suspension of anisotropic particles and the quarter waveplate with its fast axis oriented at tt/4 with respect to the x-axis, the transmitted light beam is polarized in the direction of 71/4 + 6/2, as shown in (b). Analyzer B has polarization axis oriented at 3t/4 + a as shown in (c).

Figure 4.6-12 Schematic representation of the experiment for recording the optical rotation of the sample S P vector of polarizer, i.c. direction of the electric vector of transmitted radiation, A vector of analyzer the sample rotates the electric vector of the radiation through an angle g leading (as indicated by the broken lines) to different intensities in the two experimental configurations to be realized readily with a double-beam spectrometer or sequentially with a single-beam in.strument.

Quadrapole mass analyzers are by far the most common type of mass spectrometer in use today and the literature on these type of analyzers is extensive. Quadrapole mass analyzers are often thought of as mass filters because they can be tuned to transmit ions of a narrow range of mass/charge (w/z) ratios. Fig. 6 shows a generalized block schematic of a quadrapole mass spectrometer. A typical quadrapole instrument separates ions with different masses by application of a combination of static and radio frequency electric fields to four cylindrical rods. A headspace gas sample is introduced at an inlet and fed into an ion source where electrons are emitted from a filament and ionize the sample gas. The sample ions are then accelerated in an electrical field and are injected into the opening at the center of the rods. In the simplest systems, one pair of rods is connected and attached to the positive... 

The design of the omegatron is shown schematically in Fig. 1. The omegatron functions as a small cyclotron with the important distinction that the radiofrequency electric field is distributed over the entire analyzing region and is not just applied across the faces of two D s as in the cyclotron ... 

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