Helium detector

The part-per-billion sensitivity for the fixed gases makes the helium detector the most suitable for trace analysis of these gases. A minimum detectable level of 4x10 1<4g/sec and a linear... 

Castello, G., Munari, S. Gas chromatographic analysis of gaseous atmospheric pollutants with a metastable helium detector. Chim. Ind. (Milan) 51, 469 (1969). —... 

If pressure-rise measurements indicate that a search for a leak is worthwhile then it is likely that helium will be used as a search gas and a commercial mass-spectrometer leak detector (MSLD) will be used as a selective helium detector. In practice, with a leaking system, air... 

Argon Detectors, Helium Detectors and the Electron Capture Detector... 

A chromatogram demonstrating the separation of some hydrocarbons using the thermal-helium detector and the metal-free sensor displayed in figure 7, is shown in figure 8. Included in figure 8 is the same separation monitored simultaneously with an FID. 

The pulsed helium discharge detector [7,8] is an extension of the helium detector, a diagram of which is shown in figure 11. 

The Simple or Macro Argon Detector Sensor The Micro Argon Detector The Triode Detector The Thermal Argon Detector The Helium Detector The Pulsed Helium Discharge Detector The Electron Capture Detector The Pulsed Discharge Electron Capture Detector References Chapter 7... 

The metastable atoms that must be produced in the argon and helium detectors need not necessarily be generated from electrons induced by radioactive decay. Electrons can be generated by electric discharge or photometrically, which can then be accelerated in an inert gas atmosphere under an appropriate electrical potential to produce metastable atoms. This procedure is the basis of a highly sensitive helium detector that is depicted on the left-hand side of Fig. 1. The detector does not depend solely on metastable helium atoms for ionization and, for this reason, is called the helium discharge ionization detector (HDID). 

Originally, a very complicated helium-purifying chain was necessary to ensure the helium detector s op-... 

Reimer, G.M., 1976. Design and assembly of a portable helium detector for evaluation as a uranium exploration instrument. US Geol. Survey, Open File Report, 76-398,10 pp. 

Reimer, G.M., Denton, E.H., Friedman, I. and Otton, J.K., 1979b. Recent developments in uranium exploration using the US Geological Survey s mobile helium detector. J. Geochem. Explor., 11 1-12. 

Zaikowski, A. and Roberts, E.H., 1981. Importance of resolution for helium detectors used in uranium exploration. US Dept, of Energy, Open File Report, GJBX-38(81), 19 pp. 

Figure 3. Sensitivity versus A T for 30 and 140)il thermal conductivity detectors. Reference and sample flow rates 30 ml/mln. helium. Detector temperature 140°C.

The line slope is -0.4960 The % Conilation factor is 99.9776 GAS CHROMATOGRAPHIC CONDITIONS Instrument Type Varian 6000 TCD Carrier Gas Helium Detector 0 TCD x 0.5 Detector TCD X 0.5 Injection Size CSV 0.5 ml LSV 0.2 uL Operating Conditions Isothermal at 115 C Column Description 30 x 1/8" DC-200/500 on Chrom PAW 80/100 mesh GAS CHROMATOGRAPHIC RETENTION ORDER Time Component Area 2.00 Nitrogen 119879 2.14 Methane 3582650 2.52 Caibon Dioxide 158657 2.80 Ethane 507744 3.78 Propane 325695 4.97 Isobutane 310334 5.83 n-Butane 307670 8. 50 Isopentane 177221 9.63 n-Pentane 183160 16.76 n-Hexane 19084 28.75 Heptanes Plus 20897 support package that it provides can a user have all the information necessary to support their analysis. 

Originally, a very complicated helium-purifying chain was necessary to ensure the helium detector s optimum operation. However, with high-purity helium becoming generally available, the helium detector is now a more practical system. 

Siemens SiChromat 1- 4 (single oven) SiChromat 2- 8 (dual oven) for multidimensional GC Yes Yes EID ECD ETD EPD TCD Helium detector 1. Liquid-liquid packed columns 2. Split-splitless 3. Temperature programmable 4. On-column 5. Liquid injector valve on-line 6. Gas injection valve 7. Rotary as injection valve No No Yes Yes - Yes/Yes No... 

Oj-product Ar in O2 1 ppm Ionization through high-frequency discharge of helium (helium detector) 0-100 ppm Verification Product specification... 

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