The 2006 “Test and Measurement Product Catalog” from Keithley Instruments Inc. is arranged by major product type and application area. Sections are devoted to digital multimeters and systems, specialized power supplies, RF/microwave switching and instrumentation, and optoelectronic and semiconductor test equipment. Products are presented for switching and control and for low-level measurements and sourcing, including low-current, high-resistance and low-voltage, low-resistance measurements. Tutorials on test system design and use are provided, along with suggestions on how to increase productivity and reduce the cost of testing. New products include the S501 semiconductor reliability system and the series KUSB-3100 USB-based data acquisition modules.