The Fluke 8508A is an 8.5 digit reference multimeter engineered for metrology and calibration laboratories requiring benchmark accuracy and long-term stability. This instrument consolidates DC/AC voltage, DC/AC current, resistance, temperature, frequency, and ratio measurements into a single platform, eliminating the need for multiple specialized instruments. With selectable resolution from 5.5 to 8.5 digits across most functions, it delivers 1 nV sensitivity on DC voltage and 10 nΩ on resistance. Its 365-day stability of 2.7 ppm and 24-hour stability of 0.5 ppm on DC voltage ensure traceable measurements in critical calibration workflows. The dual Paramatrix display and multiple interface options (GPIB, USB, Ethernet) enable integration into automated test systems.
Technical Specifications
DC Voltage
• Ranges: 5 (200 mV to 1000 V); maximum 1050 V
• Resolution: User-selectable 5.5 to 8.5 digits
• Sensitivity: 1 nV maximum
• Stability: 365-day 2.7 ppm, 24-hour 0.5 ppm
AC Voltage
• Ranges: 5 (200 mV to 1000 V)
• Resolution: User-selectable 5.5 to 6.5 digits
• Bandwidth: 1 MHz
• Sensitivity: 100 nV maximum
• Input impedance: 1 MΩ || 150 pF
DC Current
• Ranges: 6 (200 µA to 20 A); maximum 19.999000 A
• Resolution: User-selectable 5.5 to 7.5 digits
• Sensitivity: 10 pA maximum
• Accuracy: ±(50 ppm Reading + 50 ppm Range + 20 µV)
AC Current
• Ranges: 6 (200 µA to 20 A)
• Resolution: User-selectable 5.5 to 6.5 digits
• Bandwidth: 100 kHz
• Sensitivity: 100 pA maximum
Resistance
• Ranges: 10 (2 Ω to 20 GΩ)
• Resolution: User-selectable 5.5 to 8.5 digits
• Sensitivity: 10 nΩ maximum
• Compliance voltage: 200 V maximum
• Measurement current: 100 mA maximum
Temperature
• Measurement: 2-wire, 3-wire, 4-wire PRTs and SPRTs
• Range: -200 °C to 660 °C
• Resolution: User-selectable 5.5 to 8.5 digits
• Linearization: ITS-90 and Callendar van Dusen
• Readout units: °C, °F, K, or W
Additional Capabilities
• Frequency measurement: 1 Hz to 100 kHz
• Ratio measurement: Replaces Kelvin Varley dividers and AC/DC voltage transfer standards
• CMRR: >90 dB DC to 60 Hz (1 kΩ unbalance)
• Crest factor: 10:1 at 25% range, 5:1 at full range (200 mV to 200 V)
– Key Features
• Full 8.5 digit resolution available across all ranges
• Dual Paramatrix displays for simultaneous parameter monitoring
• Selectable resolution and measurement modes enhance laboratory flexibility
• Minimizes instrument footprint and operational complexity
– Typical Applications
• Precision voltage and current calibration
• High-accuracy resistance and impedance verification
• Temperature measurement using PRT and SPRT probes
• AC/DC voltage transfer standard replacement
• Reference-grade frequency measurement
– Compatibility & Integration
Interfaces: GPIB, USB, Ethernet | Power: 100–240 V AC, 50/60 Hz | Line fuse: T 1.25AH 250V
