Describes the desk top calculators now on the market, including manufacturers, prices, and functions performed. Provides a table of specifications for programmable desk calculators. (MLH)

The design, construction, and operation of a solid state electrometer is described. The instrument used the case and meter movement from an obsolete commercial pH meter. The cost of materials, purchased in 1977 in unit quantities, was $60. (BB)

Describes a low-cost four-color LED photometer developed to overcome the rising cost of laboratory equipment used in general chemistry labs and introduce instrumentation at the undergraduate level. The photometer detects absorbance at selected wavelengths of visible light but retains the advantages of a dual-beam system. The unit is compact and…

Identifies a trend in analytical chemistry toward greater use of instruments and a need for an understanding of the basic principles involved in instrumentation. This need can be fulfilled using homebuilt equipment; examples are provided in the areas of electrolytic conductance and electronic coulometry. (GS)

Presents a summary of the state of the field in instrumentation as it existed in 1940-1941 as described in articles written at that time by R. H. Muller. (SLH)

The construction of an operational amplifier for use in a chemical instrumentation course is described. (CP)

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)