Describes the quantitative analysis of a gaseous mixture using peak heights and ratios between the peak heights. (MLH)

Describes sensitive and specific methods used to monitor tetrachlorodibenzodioxins and tetrachlorodibenzofurans. The procedures are suitable for detecting and quantifying these substances at the parts-per-trillion levels in complex environmental and biological samples. (Author/JN)

Reported are designs for a colorimeter (absorptiometer) and polarimeter, both of which may be constructed readily with average workshop facilities and whose performance is superior to many commercial instruments commonly used in teaching laboratories. Includes pertinent diagrams, operating instructions, and sample output. (JN)

Provides a brief introduction to using the microcomputer as a piece of laboratory equipment. Focuses on the range of hardware currently available to assist microcomputer-based-instrumentation (MBI), specifically the analog-to-digital converters. In addition, discusses specification of system performance, selection and integration of components,…

Provides a general description of a preprogramed, microprocessor-based laboratory instrument, discussing its use in monitoring: (1) environmental changes; (2) distribution of count rates from a radioactive source, and (3) motion on an air tract. Includes list of the instrument's various capabilities: frequency meter, voltmeter, interval timer, and…

Some inherent instrument capabilities/limitations can be described in terms of signal to noise ratio (S/N). Two three-hour experiments are described to give students appreciation of the importance of signal strength and noise level in instrument performance and how S/N can be increased by choice of conditions and data manipulation. (Author/JN)

A Fortran IV program is described which calculates relative peak intensities of any molecular or fragment ion and displays them graphically as a bar graph resembling a mass spectrum. Documentation, including listing, sample usage, and sample execution is available free of charge. (Author/JN)

Computer applications in scientific instrumentation are traced from early data processing to modern computer-based instruments. Probable pathways toward instruments with increased "intelligence" include, among others, implementation of hierarchical computer networks and microprocessor controllers and the simplification of programing. The…

Reviews the history of vacuum technology. Includes vacuum pump developments (mechanical, ion, and cyrogenic pumps), measurement techniques, the development of the American Vacuum Society, and electronics in vacuum technology. (JN)

Describes the features and operation of an inexpensive digital pH meter. Includes a schematic diagram of the pH meter and a parts list with cost and source of each part. (SK)

Describes a ripple tank demonstration that displays interference patterns responsible for producing beats and provides photographs of computer simulations of various beat interference patterns. Includes programs for the computer simulation and equations of constructive interference paths in beat interference patterns. (Author/SK)

Describes an experiment suitable for an instrumental analysis or quantitative analysis course. (BB)

Experimental and theoretical data are presented which verifies the existence of the hydronium ion. This existence was confirmed directly by x-ray and neutron diffraction in hydrochloric acid. Recommended is the abandonment of the erroneous hydrogen ion formulation and names such as proton hydrate. (BT)

Describes the construction of a versatile signal generator suitable for use in cyclic voltammetric experiments, which can also be adapted to a conventional dc polarograph by replacing its ramp source. (MLH)

Using fourier transformation methods in nuclear magnetic resonance has made possible increased sensitivity in chemical analysis. This article describes these methods as they relate to magnetization, the RF magnetic field, nuclear relaxation, the RF pulse, and free induction decay. (CW)