This paper describes equipment and performance characteristics of an X-ray emission analyzer designed specifically for continuous, 24-hr on-line process chemical analysis and control. Analysis of elements from Mg (12) upward in the periodic chart are generally feasible.

The basic instrument is a multichannel spectrometer with provision for the simultaneous analysis of up to six elements. Either curved or flat crystals may be used as dictated by the particular application for which it is intended. X-ray detection is accomplished with flow proportional, sealed proportional, and scintillation detectors with both counter tube gas and electronic discrimination against undesired X-rays. The instrument is designed for excellent stability with provision for either automatic or simple manual standardization for long-term drift. A helium atmosphere is used for light elements, and through great care in spectrometer head design consumption is limited to 1 ft3/hr. A number of sample-presenting apparatus have been designed as companions to the basic equipment, including a continuous automatic powder, slurry, and liquid presenter. The powder presenter is particularly adaptable Co continuous analysis of materials which are finely ground (e.g., -200 mesh), whereas the slurry presenter is adaptable to continuous monitoring of solutions or finely ground particles in a slurry state. Readout is available as a d-c signal suitable for strip-chart recorders, voltmeters, data loggers, computers, and control. Digital readout and print out are also available. Performance tests in both the laboratory and field indicate an instrument suitable for on-line process use in a wide variety of industries, including cement, steel, mining, petroleum, and chemicals.