Slow Discharge Chamber

Slow Discharge Chamber. This is used for the analysis of solid metal samples. Atomization is produced by sputtering and intensive excitation radiation is focused onto the atom vapour formed. The fluorescence radiation produced is then detected at right angles to the incident radiation. The precision obtained has been about 2% for many metals and the detection limits reported have varied between 1 and 100 mgl . ... 

For large volume splitless injection the sample is introduced at a temperature below or close to the pressure corrected solvent boiling point with the split vent closed. Solvent vapors are discharged through the separation column. Compared with the split injection configuration, volatile compounds are trapped in the solvent swollen stationary phase at the column inlet rather than lost through the split vent. Since the flow rate of gas through the vaporization chamber is the same as the carrier gas flow rate, solvent elimination is slow and this method is not widely used. The maximum volume of sample that can be introduced is about 20 - 30 p.1. 

Two related gravity-driven flows are chute flow [3,33,146-155] and vertical tube flow [156-159]. Chute flow generally differs from hopper discharge in that the chute is opened so that the flow experiences a free surface. Vertical tube flow is similar to hopper flow, but there is no narrowing of the flow chamber at the outlet. A similar flow-rate scaling holds for vertical tubes [156] but the velocity profile tends to be plug like [157] for slow flows. For faster flows, density waves have been observed [159]. 

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