The Keithley 105 is a scanner mainframe that functions as a flexible, expandable data acquisition system when paired with plug-in scanner cards. It multiplexes multiple input signals into a connected measurement instrument—typically a multimeter—to automate test sequences and reduce overall test time. The mainframe accommodates two scanner cards and supports daisy-chain configuration for larger automated test equipment (ATE) applications, allowing up to 4 slave units linked to 1 master unit for increased channel density.
## Technical Specifications
**Switching & Timing**
• Programmable switching rate: 100 channels/second (10 ms interval) down to 1 channel/16 minutes (999.999 s)
• Relay drive minimum: 350 mA
• Actuation time: 2.5 ms maximum on/off
**Clock & Memory**
• Internal clock displays hours/minutes/seconds or date/month with typical error <1 minute per month
• Rechargeable 3.6 V nickel-cadmium battery backup provides approximately 1 month of data retention when powered off
**Power**
• Selectable internal switch: 105–125 V or 210–250 V, 50 Hz to 400 Hz (90–110 V and 180–220 V versions available)
• Maximum power consumption: 25 VA
## Key Features
• Two plug-in scanner card slots per mainframe
• Daisy-chain expansion: up to 5 units total (1 master + 4 slaves)
• Compatible with general-purpose, low-voltage, high-current, thermocouple, and matrix scanner cards
• Contact potential typically <±500 nV (general purpose) to 10⁹ Ω to >10¹¹ Ω depending on card type
## Compatibility & Integration
Scanner card options support signal levels from 10 V peak (thermocouple) to 300 V (high-current), currents from 10 mA to 5 A, and power ratings from 2 VA to 100 VA peak. Low-voltage cards deliver interchannel resistance >10¹¹ Ω with <10 pF capacitance. High-current cards achieve 10⁷ contact closures at maximum signal level with 0.15 Ω maximum contact resistance. Thermocouple cards maintain <1 µV contact potential with copper leads.
