The Keysight 34901A is a 20-channel multiplexer module designed for the 34970A and 34972A Data Acquisition/Switch Units. It provides high-performance multi-function switching with a scanning rate of up to 60 channels per second, integrated cold junction compensation, and two dedicated fused 1A current channels, making it the most versatile and dense multiplexing solution for diverse data acquisition applications.

Specifications

General

ParameterValue
InterfacesInternal backplane interface to 34970A/34972A mainframes

Physical

ParameterValue
Power SupplyPowered directly from mainframe backplane
Operating Temperature0 °C to 55 °C

Channel & Configuration

ParameterValue
Number of Channels20 (configured as 2-wire) or 10 (configured as 4-wire)
Dedicated Current Channels2 channels (fused, 1 A max switching current)
Total Channels22 channels
Configurable Channel PairsYes, for 4-wire resistance measurements
Internal Cold Junction Compensation SensorYes (built-in thermocouple reference junction)
Connection TypeBuilt-in screw terminals
Relay Technology TypeArmature latching
Measurement Configuration TypesDC Volts, AC Volts, 2-wire Ohms, 4-wire Ohms, Temperature (Thermocouple, RTD, Thermistor), Frequency, Period, DC Current, AC Current

Input Voltage & Current Limits

ParameterValue
Maximum Switching Voltage (DC)300 V
Maximum Switching Voltage (AC RMS)300 V
Maximum Switching Current (DC)1 A
Maximum Switching Current (AC RMS)1 A
Maximum Switching Power (W)50 W
Maximum Switching Power (VA)50 VA
Maximum Common Mode Voltage (Channel to Channel)300 V
Maximum Common Mode Voltage (Channel to Earth)300 V

DC & Signal Integrity Characteristics

ParameterValue
Thermal Offset (Thermal EMF)< 3 µV

AC & RF Performance

ParameterValue
Bandwidth (-3 dB limit)10 MHz (with 50 Ω source/load)

Switching Dynamics & Lifetime

ParameterValue
Maximum Scanning Speed60 channels/second
Mechanical Life Expectancy100,000,000 cycles
Electrical Life Expectancy (at rated load)100,000 cycles
Built-in Relay Cycle Counter SupportYes (stored in non-volatile memory on module)

Physical & Hardware Specifications

ParameterValue
Terminal Block TypeIntegrated screw terminal

Environmental & Safety Compliance

ParameterValue
Storage Temperature Range-40 °C to 70 °C
Operating Humidity Limit80% R.H. at 40 °C (non-condensing)
Operating Altitude Limit2000 meters

System Compatibility & Accessories

ParameterValue
Compatible MainframesKeysight / Agilent 34970A, 34972A

Measurement Capabilities

ParameterValue
Supported Thermocouple TypesB, E, J, K, N, R, S, T

Technology

Armature Relay

Applications

Data Acquisition, Multiplexing, Temperature & Electrical Testing