HP / Agilent 44421A RELAY MULTPLXR

The HP/Agilent 44421A is a 20-channel relay multiplexer module that routes signals from multiple sources to measurement instruments within automated test systems. Designed as a plug-in assembly for the Agilent 3497A Data Acquisition System, it provides flexible signal path management through a three-line configuration per channel: High, Low, and Guard. The 20 channels are organized into two groups of 10, allowing one channel per group to close simultaneously. Relays can be operated in random sequence or incremented between programmable limits, supporting both single-point switching and multi-channel configurations for four-terminal resistance measurements.

– Technical Specifications

• Channels: 20 total, organized into two groups of 10
• Relay Configuration: Three lines per channel (High, Low, Guard)
• Channel Operation: One channel closeable per decade group; random sequence or programmed limit operation supported
• Thermal Offset: Low thermal offset for precision low-level signal conditioning
• Signal Routing: Directs channel outputs to 3497A DVM or connected measurement instruments

– Key Features

• Low thermal offset enables accurate measurements of transducers and temperature sensors
• Multi-line architecture supports guarded signal paths for noise-sensitive applications
• Grouped channel organization allows parallel switching of independent measurement circuits
• Four-terminal resistance measurement capability when two channels per decade are closed
• Programmable relay sequencing for automated measurement protocols

– Typical Applications

• Automated test and measurement systems with multi-channel signal selection
• Transducer and sensor signal conditioning
• Precision low-level measurement setups
• Four-terminal resistance and impedance characterization
• Electronic design verification test benches

– Compatibility & Integration

The 44421A functions as a dedicated multiplexer card within the Agilent 3497A Data Acquisition System ecosystem, providing native integration with 3497A DVM functions and data logging capabilities. Option 010 designates the 20-channel relay multiplexer assembly configuration.