The Hewlett-Packard Model 3456A is a versatile Digital Voltmeter with ac, dc, ohms, and various math functions. This voltmeter is an excellent bench meter and since it is remotely programmable it is an exceptional system measurement device. Other features for which you may have some good uses are the selection of power line cycles integrated, the selection of certain number of readings/trigger, settling delay, ratio, and other unique and useful functions. The 3456A also employs a feature called AUTO ZERO. This feature of the instrument is very useful for good stability. The internal reference device and reference resistors are also selected for good accuracy and stability. Another good feature is the TEST function of the 3456A. With this function the instrument’s operation can be partially verified for correct operation by the operator.