Agilent/Keysight 2804A

The Agilent/Keysight 2804A represents two distinct discontinued instruments: a precision quartz thermometer and a high-voltage differential probe. The 2804A Quartz Thermometer delivers absolute accuracy of ±0.04 °C across a -80 °C to +250 °C range with 0.0001 °C resolution, featuring NBS traceability to IPTS-68 and adjustable ice-point or triple-point calibration. The N2804A High-Voltage Differential Probe extends measurement capability to ±300 VDC + peak AC with 300 MHz bandwidth and 100:1 attenuation, achieving >70 dB CMRR at 1 MHz through 4 MΩ differential input resistance and 4 pF input capacitance.

Technical Specifications

• Absolute accuracy: ±0.04 °C


• Temperature range: -80 °C to +250 °C


• Resolution: 0.0001 °C or 0.001 °F


• Display modes: Absolute or differential temperature


• Calibration traceability: NBS (IPTS-68) High-Voltage Differential Probe


• Bandwidth: 300 MHz (without extension leads)


• Maximum differential voltage: ±300 VDC + peak AC


• Attenuation ratio: 100:1


• Common mode rejection ratio: >70 dB at 1 MHz


• Differential input resistance: 4 MΩ


• Input capacitance: 4 pF


• Zero offset: Adjustable

Key Features

• Extension leads (30 cm) incorporate built-in damping resistor for resonant frequency suppression and flat frequency response


• Quartz thermometer interfaces via HP-IB with variable resolution analog output


• Probe powered directly from oscilloscope AutoProbe interface


• Supplied accessories: two alligator clips, two pincer clips, two 30 cm extension leads, trimmer tool

Compatibility & Integration The N2804A probe integrates with Keysight InfiniiVision and Infiniium Series oscilloscopes through the AutoProbe interface, enabling conventional earth-grounded oscilloscopes to perform safe floating signal measurements.

Product Status Both the Agilent 2804A Quartz Thermometer and Keysight N2804A High-Voltage Differential Probe are discontinued and no longer supported by Keysight.