OS-270 Resistance Box IET LABS

OS-270 Resistance Box – IET Labs

Precision Handheld Resistance Source for Calibration and Testing

The OS-270 from IET Labs is a compact, high-resolution resistance box designed for accurate resistance simulation and measurement tasks. With a fine resolution of 0.01 Ω, it is ideal for applications that require detailed control and precision, such as electronic testing, sensor simulation, and educational labs.

Unlike traditional rotary resistance boxes, the OS-270 uses a digital microprocessor-based system with a calculator-style keypad for fast and direct input of resistance values. It’s a manual device, meaning it doesn’t support computer control, but its intuitive operation and versatility make it a powerful tool in the lab or field.

Equipped with advanced features like memory functions, quick-access buttons, and dual display for simulating real-world sensor data (e.g., temperature, pressure, strain), it also includes built-in protection such as a current limiter and an open-circuit function for safety and ease of use.

Key Features

• Digital, microprocessor-controlled operation with keypad input

• 0.01 Ω resolution for fine resistance adjustment

• Quick memory recall for frequently used resistance values

• Stores up to ten user-defined resistance presets

• Built-in current limiter to protect against overloads

• Open-circuit key to disconnect output instantly

• Auto-correction for internal residual resistance

• Dual display for resistance and sensor value simulation

Typical Applications

• Simulating RTDs, thermistors, and other sensors

• Calibrating meters and electronic instruments

• Troubleshooting in production or R&D settings

• Use in teaching environments and technical training

Specifications

• Resistance range: 1 Ω to 1.5 MΩ (approx.)

• Resolution: 0.01 Ω

• Accuracy:

  • ±0.1 Ω for values ≤ 1 kΩ

  • ±0.01% for values > 1 kΩ

• Residual capacitance: 7 pF typical

• Power handling: 1.0 watt

• Power source: 4 AAA alkaline batteries

• Dimensions: 3.3 x 6.6 x 1.25 inches

• Weight: 1.1 lbs

The OS-270 is a precise, easy-to-use resistance substitution box, ideal for professionals and technicians requiring reliable manual resistance control in a compact, battery-powered form.