The report discusses the development of analytical instrumentation to field monitor the major odorous compounds emitted from animal rendering plants. The recommended analytical methods suitable for field monitor development are summarized. The laboratory showed that the 3-methyl-2-benzothiazolone (MBTH) aldehyde method, the ninhydrin measurement for amines, and the ferric ammonium sulfate - ortho - phenanhroline method for organic sulfur compounds (oxidized to SO2) offered the best promise of adaption for tape monitoring instruments. The analytical methods, laboratory tests, and design and development problems for each monitor are presented. Final testing of the monitors in a rendering plant led to minor modifications. Comparison of several amine and sulfur monitor readings with odor panel evaluation of concurrent samples showed these instruments could record concentrations at or below the federal guideline concentration of 5.6 OU/cu. meter.