520A Electronic Development Standard

Additional Features:

• 100mV/10V/100V ranges
• 100mA/10mA 
• Accuracy: ± (0.002% of setting + 0.005% of range + 3 uV
• Stability: 8 hrs: 0.00075%; 24 hrs: ±0.001%; 90 days: ±0.0015%; 1 year: ±0.002%
• Line and Load Regulation: ±0.0005% No load to full load ±10.0% line fluctuation
• Noise and Ripple: rms: ±0.0005% of range + 2 uV in a band pass of 0.1 Hz to 100 kHz
• Current Mode: Accuracy: ±0.005% of setting + 1 uZ
• Stability: 8 hrs: ±0.001%; 24 hrs: ±0.002%; 90 days: ±0.005%; 1 year: ±0.0075%

General Specifications

• Isolation: Power transformer to analog output: 2.5 x 10 4 m Ohms, 300 pF
• Control logic to analog output: optically isolated: 10 9 Ohms, 130 pF, 500 Vdc
• Temperature Coefficient: Ambient: ±0.0005%/°C; Operating Limit: ±0.0010%°C
• Switching and Settling Times: Step Changes: 5 ms; Range Changes: 1 s
• Protection: Voltage mode: Short-circuit and overload protection. Current mode: Open-circuit protection. Front panel enunciator will indicate malfunction condition. Recovery is automatic.
• Warm-up time: 2 hours
• Power Requirement: 50 watts; 115 V or 220 Vac ±10%; 50/60 Hz
• Calibration Temperature: 23°C ±1 °C
• Ambient Temperature: 20°C to 30° C
• Operating Limit: 10°C to 50°C
• Storage Temperature: -40°C to 85°C
• Terminals: Output: Front panel mounted, 5-way binding posts which are floating, opto-isolated from the 488 bus, guarded, remote sensed (4 wire) and case ground. Rear panel mounted 6 pin Amphenol spec. connector (mate supplied) with the same functions as those for the front panel connections.
• Program: Rear panel mounted connector conforming to IEEE-488
• Mounting: Rack mounting facilities: standard 19 inches, 482.6 mm and for bench use with convenient, and removable tilt bale.

The Electronic Development 520A is a microprocessor controlled enhanced version of the field proven Model 520. An industry standard 6500 series microprocessor has been incorporated to improve the reliability, and versatility of the instrument. The Model 520A Programmable DC Voltage Standard is a highly versatile reference source, designed to meet the needs of computer systems, production line testing, automated calibration, and standards laboratories.

The instrument has a specified accuracy, and is traceable through a bank of saturated standard cells to the National Bureau of Standards. Resolution of each range, in each function, is 1 part per million.

The 520A is a highly accurate reference which can be used for calibration of digital voltmeters, analog meters, semiconductor analyzing systems, analog references for computers, analog-to-digital converters, telemetry and data acquisition systems, and wherever a stable source is required.

The variable, constant current mode is designed for use in calibration and simulation of strain gages and other transducers. There are no adjustments made during normal operation; the trims are made during calibration and are made during calibration. The circuitry is completely solid state made of discrete, hybrid and/or integrated circuits packaged on etched glass circuit boards. These are proven circuits, using derated components to insure long life and maximum reliability.

The 520A is overload and short-circuit proof, and is fully operational in normal environmental conditions. The Standard Source will drive a short circuit indefinitely without damage to the instrument, and will recover to rated specifications in less than 100us.