The article discusses an aspect of conductivity, one of the electrical properties subdivisions, and describes a tester that can be shop-built. Breakdown voltage of an insulation material is specifically examined. Test procedures, parts lists, diagrams, and test data form are included. (MF)

Describes the design of a sequential switcher to be used for multichannel strip-chart recordings of temperatures at different points in a solar heated building. (GA)

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)

Describes the use of integrated circuit voltage regulators in electrolytic titration instruments. (MLH)