The 3490A five-digit integrating digital multimeter is an early microprocessor-based instrument that was one of the first to rely heavily on software for its operation. HP heavily marketed the 3490A's built-in self-diagnostic capabilities, which provide extensive tests of nearly all internal circuitry. Using the front-panel-accessible test modes, one can quickly check out the basic internal functions of the multimeter in less than a minute, and establish a high degree of confidence in its operational status.
The instrument measures DC and AC voltage, and resistance in four-wire mode. Manual or automatic ranging can be selected, and the sample rate is variable using a front-panel rotary switch. Manual sampling via pushbutton is also available.
Remote control and remote readout options are available using the BCD interfaces that were common at the time.
The instrument pictured below is equipped with Option 040, Sample/Hold.
Subjectively, despite its age, the 3490A is a useful and very nice bench meter even by today's standards.
|Option 020||Systems Expand|
|Option 021||Digital Output (requires Option 020)|
|Option 022||Remote Control (requires Option 020)|
|Option 030||ASCII Data Input/Output (HPIB)|
|Option 045||Sample/Hold (without Option 020 or Option 030)|
|Option 050||Noise Rejection for 50Hz operation|
|Option 060||Noise Rejection for 60Hz operation|