The Model 8810A is a 5]/2-digit, fully guarded digital multimeter designed for use in bench-top or rack mounted applications. It features five dc voltage ranges, autoranging, dual-slope a/d conversion, auto polarity, overload protection, and an automatic display-overload indication. DC voltage measurement capabilities include five ranges from 200 mV to 1200V with a maximum sensitivity of 1 /zV. Circuit loading is virtually eliminated on the 200 mV, 2V and 20V ranges by an input resistance > 109 ohms. The resistance is 107H on the 200V and 1200V ranges. Each range can be manually selected by depressing an appropriate front panel range switch. Autorange can also be manually selected as a range. It offers convenient operation plus optimum accuracy and resolution when frequent range changes are required. All dc voltage ranges will withstand the continuous application of inputs up to 1000V dc or 1100V peak ac. Measurement data is displayed on a 5Vl-digit LED readout. The readout is continuously updated and includes decimal point, polarity (Vdc only) and a 200 mV dc range annunciator (20 M O and 2000 annunciators are also included for use with the Ohms Converter Option). When a range overload occurs (full scale count of 199999 is exceeded) the display will flash 188888 as an overload indication. Measurement capabilities of the 8810A can be increased by the addition of one or more of the available options and accessories listed in Table 1-1. All options, with the exception of the Digital Output Unit, are field installable by the user, if calibration facilities are available. Options may be ordered at time of purchase or at a later date. The basic 8810A will accommodate 1 - Ohms Converter Option, 1 - AC Converter Option and/or 1 - Digital Output Unit.