Keithley 7057A 9-Channel Thermocouple Scanner Card

The Keithley 7057A is a 9-channel thermocouple scanner card engineered for integration into Keithley scanner mainframes. It delivers automated, high-precision temperature measurements by multiplexing signals from multiple thermocouple sources while maintaining sub-microvolt contact potential and integrated cold junction compensation. The card combines thermocouple scanning with an onboard temperature reference function, eliminating the need for external compensation and enabling accurate thermal profiling across distributed measurement points.

Technical Specifications Channels & Switching

9 thermocouple channels plus 1 temperature reference channel

2-pole Form A relay configuration with common guard

Contact potential: less than 1 µV per channel ( 10⁸ closures cold switching; > 10⁶ closures at maximum signal levels

Relay drive current: 12 mA typical Signal Handling

Signal level: up to 35 V peak; up to 100 mA peak (resistive load only); 2 VA maximum (non-inductive load only)

Channel isolation: > 10⁸ Ω, 10 pF

Input isolation: > 10⁷ Ω, 150 pF

Common mode voltage: 200 V peak Temperature Reference

Type: Linearized thermistor bridge

Output: −1 mV/°C (0 mV at +30°C)

Accuracy (1 year): ±0.25°C (10°C to 35°C); ±0.5°C (0°C to 10°C and 35°C to 50°C)

Temperature offset: ±0.05°C maximum within isothermal block; ±0.1°C maximum between any two terminals

Dynamic offset: ±0.1°C maximum after one hour settling following 10°C environmental step change

Warm-up time: 1 hour to rated accuracy Physical & Connectivity

Dimensions: 32 mm H × 114 mm W × 272 mm L

Weight: 0.54 kg

Connections: Screw terminals (#4) on isothermal block; accepts #18 AWG wire maximum

Operating environment: 10°C to 35°C

Key Features

Unified thermocouple scanning and temperature reference on a single card

Sub-microvolt contact potential eliminates measurement drift

Isothermal block design minimizes inter-channel temperature gradients

Low relay drive current reduces mainframe power demands

High channel isolation enables multi-point monitoring in electrically noisy environments

Typical Applications

Thermal profiling across semiconductor processes and manufacturing equipment

Environmental and chamber monitoring with distributed sensor networks

Process control requiring simultaneous multi-point temperature feedback

Equipment validation and thermal characterization studies

Compatibility & Integration The 7057A installs directly into Keithley scanner mainframes via rear-panel connectivity. Its compact form factor and standardized screw terminal interface facilitate integration into existing multi-channel measurement systems without external reference hardware.