The casting of iron is largely a chemical process: that is, the chemistry of molten iron greatly influences the properties of finished castings. Other parameters - casting design, mold integrity, inoculation practice, pouring temperature, and shakeout procedure - are also vital to consistent production. But if the chemistry is wrong, the probability of defective castings is high. For this reason, control of chemical composition has long been a major objective of foundrymen.
To be useful for either process control or quality assurance checking, analytical work must be reliable and accurate. Data should also be available in a minimal period of time to make possible the on-line adjustments necessary to achieve proper chemistry, and thus the desired properties, in the final castings.