Flame photometric analyser for detecting contaminants in oxygen - with remote photomultiplier, allowing higher operating temperatures and increased sensitivity

摘要

Flame photometers detect contaminants in oxygen-contg. gases. Such appts. incorporates a burner and an analysis unit. The burner is housed in a space into which hydrogen is passed and reacts in two stages with the oxygen-contg. gas. The analysis unit incorporates a photomultiplier which sees, through an interferential filter, the flame produced in the first stage, i.e. when hydrogen is in excess in relation to the oxygen in the gas. The burner housing is heated to =100 degrees C. generally 120 degrees C and the photomultiplier is mounted remote from the housing and connected to it optically by a light pipe of optical fibres. The interferential filter is placed at the end of the pipe at the entry of the photomultiplier. The invention allows the operating temps. to be increased without affecting the photomultiplier. The ability to operate at higher temp. increases the sensitivity of the appts. partic. to materials of low volatility.