Discusses major themes and interrelationships common to bioselective potentiometric membrane electrodes including the nature of bioselective electrodes, applications, and future prospects. Includes tables on traditional ion-selective membrane electrodes, nontraditional electrodes, and typical biocatalytic potentiometric electrodes. (Author/JN)

Describes a semi-automatic viscometer which incorporates a microprocessor system and uses optoelectronics to detect flow of liquid through the capillary, flow time being displayed on a timer with accuracy of 0.01 second. The system could be made fully automatic with an additional microprocessor circuit and inclusion of a pump. (Author/JN)

Describes modification of a gas viscometer to produce a low cost instrument with high precision and safe design. Three tungsten electrodes are mounted in the viscometer using graded glass seals and a ball trap is inserted between mercury reservoir and all external stopcocks. Also describes modifications in experimental procedures. (Author/JN)

Describes the procedure, the circuitry, and the calibration required to convert a voltmeter into a pH meter for use in the physics laboratory. (GA)

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)

Addresses solution nonmetal determinations on a fundamental level. Characterizes research in this area of chemical instrumentation. Discusses the fundamental limitations of nonmetal atomic spectrometry, the status of nonmetals and atomic spectroscopic techniques, and current directions in solution nonmetal determinations. (CW)

A review is given of electronic environmental meters available for use in schools. Included are conductivity, oxygen, pH, and temperature meters. Chemical test papers and kits for use in environmental studies are included. (BB)

Presents the construction aspects of a simple but reliable colorimeter made from locally available components. Notes the absorption range to be 400-750-nm. Lists seven experiments done on the instrument. (MVL)

Discusses the importance of ion chromatography in separating and measuring anions. The principles of ion exchange are presented, along with some applications of ion chromatography in industry. Ion chromatography systems are described, as well as ion pair and ion exclusion chromatography, column packings, detectors, and programming. (TW)

Discusses the value of electrophoresis in the fields of protein chemistry and biochemistry. Describes how to build an inexpensive electrophoresis setup for use in either research or teaching activities. Details the construction of both the separating device and the power supply. (TW)

Describes an interface that uses semiconductor metal oxides to detect low gas concentrations. Notes the detector has long life, high stability, good reproducibility, low cost, and is able to convert the gas concentration to an electrical signal with a simple circuit. Theory, schematic, and applications are provided. (MVL)

Presents a low cost system with easily replaced electrodes for use in general chemistry. Notes the accuracy and wide applicability permit easy use in physical or quantitative chemistry experiments. Provides schematic, theory, and helpful suggestions. (MVL)

Presented is a photoelectric colorimeter which can be assembled by the student. Reports that it can do many of the same analyses as the SPEC 20 but at a greatly reduced cost using older technology. Presents several experiments to use with the colorimeter. (MVL)