The Krohn-Hite Model 523 Precision DC Source is a highly stable and repeatable dc voltage source and dc current source providing N.I.S.T. traceable voltages and currents for use in production, calibration labs, QA and QC departments, design labs, or any place where an accurate voltage and current source is needed.

Using Krohn-Hite’s state-of-the-art reference, the 523 provides accurate and stable voltages from ±10nVdc to ±110.99999Vdc to within ±4ppm for 90 days (±8ppm for 1 year), and precise currents from ±10nA to ±110.99999mA to within ±8ppm for 90 days (±16ppm for 1 year). It is an extremely quiet source with <7 Vrms of noise measured over a 10Hz to 100kHz bandwidth (<2 Vrms 0.1Hz to 10Hz).

The 523 features a user friendly 7½ digit display and a membrane keyboard entry of all settings. Output settings can be modified using a plus/minus delta function, multiply/divide function and curser control keys that allow placing a curser on any digit to increment or decrement its value. Output 2-wire, 4-wire and chassis grounding are accomplished with one keystroke or over the GPIB interface bus. A crowbar function places the output in a safe mode when desired. The 523 output can be set to 0 volts, allowing the output sense to maintain a true 4-wire low impedance zero output. It is also quickly forced to zero before a range change to prevent any "surprise voltages" from appearing.

An AUTO ZERO OFFSET CALIBRATION (AZOC) returns any thermally generated offsets to within specified limits and is accessible via the front panel or over the GPIB interface bus. The unit is designed for a "Covers On Calibration” using the KH523CAL Test and Calibration Software Program (Field Calibration License required). With the KH523CAL program and either an HP3458 or Fluke 8508A Digital Voltmeter, unattended calibrations can be made in approximately 15 minutes.

The 523 provides for the storage of up to 31 output settings that can be recalled at any time. Internal operating temperature, serial number, last calibration date and firmware version can all be called to the display for quick access when needed. Error messages are displayed when incorrect or out-of-range entries are made.

APPLICATIONS
Krohn-Hite's NEW Model 523 is well suited for many applications where an extremely accurate and stable dc voltage or dc current is needed. At a cost much less than most sources in its class, the 523 can be a valuable asset to any company's production line, calibration lab, QA and QC department and design lab.

OUTPUT SPECIFICATIONS
The following specifications are with a constant internal operating temperature equal to 40ºC ±1ºC. The HP3458A NPLC is set for 100 and AUTO CAL cycle (ACAL) run. The Model 523’s calibration is normally done at a room temperature of 23ºC ±1ºC. The internal Cal Temp is saved at the time of calibration and can be displayed with the present internal temperature using the [TEMP] key.

The 90 day and 1 year specifications are within 24 hours of a zero CQL (AZOC) cycle,  and a constant internal operating temperature equal to 40ºC ±1ºC. The zero CAL (AZOC) cycle takes out the effect of internal DC offset drift.