Drift gas inlet

Figure 6. Diagram of our 1-atm ion mobility spectrometer (IMS) apparatus (a) stainless steel source gas dilution volume, (b) septum inlet, (c) needle valve, (d) Nj source gas supply, (e) source and drift gas exhaust, (f) flow meter, (g) pressure transducer, (h) insulated box, (i) drift tube, (j) ion source, (k) Bradbury-Nielson gate, (I) Faraday plate/MS aperture, (m) drift gas inlet, (n) universal joint, (o) electrostatic lens element, (p) quadrupole mass filter, (q) 6"-diffusion pump, (r) first vacuum envelope, (s) channeltron electron multiplier, (t) second vacuum envelope, (u) 3"-dif-fusion pump, (v) Nj drift gas, (w) leak valve, (x) on/off valves, (y) fused silica capillary, (z) 4-liter stainless steel dilution volume, (aa) Nj gas supply.

Fig. 9.4.8 Apparatus for the gas flow-cold trap method. One of the gas inlets is abbreviated in the figure. A cover in the figure is used to improve a collection yield. Without this, the particles produced just above a crucible are drifting in the chamber to deposit on the chamber wall. The end of the gas line is evacuated by a rotary pump so as to constantly flow the carrier gas. A solvent feeder is inserted on the gas line for the sublimation of organic liquid to deposit at the trapping apparatus cooled with liquid nitrogen. (From Ref. 10.)...

Fig. 2. Perspective cross sectional view of the temperature controlled drift cell after Kemper and Bowers design [22] (a) cooling line, (b) cell body, (c) buffer gas inlet, (d) cell end cap, (e) drift guard ring, (f) ion entrance hole, (g) ion focusing lens, (h) ceramic ring, (i) ion exit hole, (j) ceramic rod holding guard rings, (k) ceramic rods holding cell assembly...

Figure 4.41. Schematic diagram of cell for temperature- and atmosphere-controlled measurements using DRIFTS accessory shown In Fig. 4.25 (1) cell cover (38.1 x 21 x 3.2 mm) (2) window (16x2 mm) (3) cell assembly (38.1 x 21 x 29.2 mm) (4) cartridge heater (12.7 X 38.1 mm) (5) thermocouple (6) gas Inlet (0 = 6.35 mm) (7) gas outlet (0 = 6.35 mm). Reprinted, by permission, from B. Li and R. D. Gonzalez, > pp/. Spectrosc. 52, 1488-1491 (1998), p. 1489, Fig. 2. Copyright 1998 Society for Applied Spectroscopy.

Figure 2 - Schematic view of the cooled static drift tube primary ion source (F, filament IR, ionisation region SI, source gas inlet) SQ, primary ion selector quadrupole L1 and L2, focusing lenses DT, drift tube FP, front plate RP, rear plate E1 and E2 aperture plate, AQ, analyser quadrupole CM, channel multiplier ...

We reiterate that the intrinsic time resolution of the PTR-MS instrument can be faster than the nominal gas residence time. However, other factors may work to lower the practical time resolution, including the adsorption and slow release of molecules on the surfaces of the gas inlet line and the walls of the drift tube (a so-called memory effect). Moreover, if the ion signal is weak then data may need to be accumulated for some time to achieve an acceptable signal-to-noise ratio, and therefore this may be the key factor dictating the ultimate time resolution of any measurement. With regard to memory effects, by operating the gas inlet and drift tube at a high temperature Mikoviny et al. were able to reduce... 

The samples were raw ewe s milk, raw cow s milk and raw goat s milk. Cream was separated from milk by centrifugation, and TGs were extracted with n-hexane. For the HPLC analysis, two stainless steel columns, 25 cm and 15 cm X 4.6-mm ID with 3 /zm Spherisorb ODS-2 (Phase Separations, Queensferry, United Kingdom Symta, Madrid, Spain) were connected in series. The mass detector (ACS 750/14 The Arsenal, Macclesfield, United Kingdom) drift tube temperature was 45°C, and the inlet gas pressure was 1.38 bar. The mobile phase consisted of a... 

An electrostatic precipitator is to be used to treat 100,000 acfm of a gas stream containing particulates from a hazardous waste incinerator. The proposed precipitator consists of three bus sections (fields) arranged in series, each with the same collection surface. The inlet loading has been measured as 40 gr/fl and a maximum outlet loading of 0.18 gr/ft is allowed by local Environmental Protection Agency (EPA) regulations. The drift velocity for the particulates has been experimentally determined in a similar incinerator installation with the following results ... 

The proposed model of AP/MALDI includes the ejection of a plume of positive and negative ions after a laser pulse. Tlie ion ejection is followed by ion drifting under the influence of the electric field and gas flow near the inlet to the mass analyzer. Positive ions can also recombine with negative ions during the initial stages of... 

On its way from the Venturi-type inlet to the downstream end of the drift section, HsO" ions undergo nonreactive and reactive collisions with any one of the conponents of air [51,52]. The water reagent gas PICI process causes the analyzed VOCs to be converted into [M+H] ions. 

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