This instruction manual contains complete operating instructions for the Keithley Model 192. Detailed descriptions of the available options for the Model 192 are provided (separate instruction manuals are supplied with the Model 1920 and Model 1923), along with a theory of operation, calibration and service instructions for maintaining the instrument. A complete parts list with schematics and component layouts is also provided at the end of this manual. The Model 192 is a 6 1/2 digit, 2,000,000 count, fast autoranging DMM. With the IEEE-488 Interface option (Model 1923), the Model 192 becomes fully programmable. DC Volts and Ohms functions are standard. Measurements of 1µV to 1200V are attainable on 5 voltage ranges, and 2-and 4-terminal measurements of 1 mΩ to 20 MΩ are attainable on 6 resistance ranges. With the addition of the Model 1910 AC Voltage Option, the Model 192 will provide readings from 10µV to 1000VAC on 4 ranges. True Root Mean Square (TRMS) AC voltages can also be attained with the use of the Model 1920 TRMS ACV Option. Because the Models 1910, 1920, and 1923 are easily field installed, these options can be added at any time. 1.2 FEATURES The Model 192 includes the following features: • Front Panel Programs—The internal programs in the Model 192 are accessible from the front panel. Descriptions of these programs can be found in the detailed specifications which precede this Section and in Section 5. • Data Storage — Registers for storing 100 readings are provided in the basic Model 192. These storage registers are utilized by Front Panel Program 7, Data Logger (see Section 5). • Multiple Inputs —Multiple inputs provide access to DCV, ACV, and Ohms terminals simultaneously. This enables systems designers to optimize their switching matricies for the parameter being measured. In addition, in some simple systems, switching can be eliminated altogether. For systems that require only one input, the Model 1924 Rear Panel Input Adapter is available as an option. • One Button Zero—The front panel zero is activated by pushing one button. The zero offset is automatically scaled when a new range is selected. Unique offset settings are saved for each function.