The HP 432A is an automatic, self-balancing thermistor power meter designed for use with temperature-compensated thermistor sensors. It measures the output voltage of the thermistor bridges and computes the corresponding power, allowing high accuracy to be maintained even on the most sensitive range because the error due to thermoelectric effect is reduced to a negligible level.

The 432A is used with HP thermistor mounts and microwave sensors (including HP 478B, 8478B, and 486 series mounts) to perform RF and microwave power measurements across the operating range of the mount. Each thermistor mount is furnished with data stating the Calibration Factor and Effective Efficiency at various frequencies, and the 432A's front-panel 13-position calibration factor control — calibrated in 1% steps from 88% to 100% — compensates for losses in the mount and eliminates the need for separate calculation.

ValueTronics has supplied refurbished and tested HP, Agilent, and Keysight power measurement equipment to RF, microwave, and calibration laboratories for over three decades. Each {{CONDITION}} HP 432A passes through our 20,000 sq ft secure facility at 1675 Cambridge Drive in Elgin, Illinois, where it is performance-tested, cleaned, and prepared for shipment by technicians familiar with the thermistor power measurement family.

Brand Heritage

Hewlett-Packard's test and measurement business was spun out as Agilent Technologies in 1999 and then transferred to Keysight Technologies in 2014. HP 432-series power meters and the companion 8477A calibrator predate both transitions but remain part of the lineage now associated with Keysight's power measurement product line.

Compare Other Models in This Series

The HP 432 Series consists of two thermistor power meters that share the same automatic self-balancing measurement architecture and temperature-compensated thermistor sensor compatibility, differing primarily in display type and range coverage. Both instruments are designed around the same accuracy class — high accuracy with negligible thermoelectric error — and both use the same calibrated thermistor mounts with front-panel calibration factor control.

The 8477A is not a power meter but the dedicated calibrator for the 432 family. It allows users to verify full-scale meter readings on all ranges and confirm meter tracking by connecting three cables between the power meter and calibrator, without requiring charts or additional instruments.

Each pre-owned model below is its own dedicated product page with condition-matched pricing and availability. Select the model that fits your application, then choose the condition tier that fits your budget and documentation requirements.

The 432A is the analog-meter member of the family, featuring a taut-band suspension mirror-backed meter movement with a milliwatt scale more than 108 mm long across seven full-scale ranges from 10 μW to 10 mW. It is the lighter and lower-power-consumption variant (1.5 watts, 2.3 kg net) and is the only member of the family for which the Option 001 rechargeable battery is available, supporting up to 20 hours of continuous operation.

The 432A uses an analog taut-band meter with seven full-scale ranges (10, 30, 100, 300 μW, 1, 3, 10 mW) and consumes 1.5 watts. The 432B uses a three-digit digital display with one digit of overrange and 20% overrange capability on all ranges, has four full-scale ranges (10 and 100 μW, 1 and 10 mW), consumes 10 watts, and is the only family member with BCD output (8-4-2-1 code, TTL compatible, with Print and Inhibit lines for use with the HP 5150A Option 002 BCD digital recorder).

The 8477A is the family's calibrator, not a measurement instrument: it operates from 115 or 230 Vac ±10% at 3 watts and is used to verify 432-series meter accuracy across all ranges. See the comparison table for full specifications by model.

Additional differences in specifications beyond the few shown above are not listed here — see each model's full specifications below.

Product Core & Specifications

About this used unit

• Warranty included
• Functional verification included
• Standard Calibration Upgrade Options: No Calibration Required, NIST Traceable, Z540.1 or ISO 17025 with Data, Z540.3 Guardbanding with Data.
• Note that unnecessary accessories may not be included (contact Test Architect to confirm).

Please review the Manufacturer's Data Sheet to verify published specifications. Feedback on this webpage is always welcome — please reach out to your Test Architect at any time for questions or concerns. Thank you, we truly appreciate you being our customer.