Keithley 247 DC Power Supply

The Keithley 247 is a precision-regulated linear DC power supply delivering 0 to 3 kV DC at up to 6 mA for high-voltage measurement applications. This unit combines AC-to-DC conversion with a solid-state DC converter topology, generating stable, low-noise outputs suitable for sensitive instrumentation. Its fully encapsulated high-voltage assembly ensures arc-free operation across demanding test environments.

The 247 excels in photomultiplier tube characterization, resistivity measurements, ion chamber biasing, and radiation detection systems. It pairs directly with Keithley electrometers and picometers, providing the regulated bias voltage these instruments require. Polarity selection—positive or negative with respect to chassis—accommodates varied circuit topologies.

## Technical Specifications

**Output Performance**
• Voltage: 0 to 3 kV DC
• Maximum current: 6 mA DC
• Power output: 18 W
• Accuracy: ±0.25% of setting + 1.5 V DC (1% to 100% of max voltage)
• Dial resolution: 200 mV graduations
• Stability: ±0.01% of setting per hour
• Line regulation: 0.001% voltage change per 10% line variation
• Load regulation: 0.005% voltage change from no-load to full-load
• Ripple and noise: 3.5 mVrms, 10 mVp-p at 3 kV / 6 mA; 1 mVrms, 3 mVp-p at 1 kV / 1 mA (10 Hz to 100 kHz)
• Settling time: 4 seconds to ±1 V with full resistive load

**Input Power**
• AC voltage: 90–125 V / 180–250 V selectable
• Frequency: 50–60 Hz
• Consumption: 130 VA

**Environmental**
• Operating temperature: 0°C to 50°C
• Operating humidity: 0% to 80% RH (up to 35°C)
• Storage temperature: −40°C to 75°C

## Key Features

• Selectable positive or negative polarity
• Short-circuit proof with arc-protected, self-restoring design
• MHV Type UG931/U rear-panel output connector
• Compact 19 in × 3.5 in × 10.75 in form factor (483 mm × 89 mm × 273 mm)
• Four rack-mount holes; bench feet included
• Weight: 5.9 kg (13 lbs)

## Typical Applications

• Photomultiplier tube bias and characterization
• Resistivity and conductivity measurements
• Ion chamber operation
• Radiation detection systems
• Precision electrometer biasing

## Compatibility & Integration

Ship includes UG932/U mating connector and instruction manual. Mounts in standard 19-inch racks or operates on bench with supplied feet.