Photo Sensor (ActiveTwo)

This Photo Sensor is specifically designed to work with the ActiveTwo from BioSemi. It is a high-accurate light sensor to measure visual stimuli during EEG acquisitions. It is commonly used to measure the change in contrast on a screen, which indicates the precise time a visual stimulus is presented and with nearly no delay (sub-nanosecond delay from the rise-time and A/D conversion).

This sensor is made up of a light-to-voltage sensor that combines a photodiode and a trans-impedance amplifier (feedback resistor = 16 MW, 8 MW, and 2.8 MW respectively) on a single monolithic IC. The output voltage is directly proportional to the light intensity (irradiance) on the photo sensor. Such sensors improve amplifier offset-voltage stability and low power consumption and are supplied in a 3-lead clear plastic package with an integral lens. The photo sensor is a sensitive PIN diode with an integrated trans-impedance amplifier.

This photo sensor comes with a 2m connection cable and DIN type plug, which connects to the Ergo input of the ActiveTwo EEG System (requires ERGO input).

One Photo Sensor (ActiveTwo) per pack.

Technical Specifications

• Sensor Type: Light-to-Voltage Sensor
• Cable Length: 2m
• Connectors: DIN Type Plug for ActiveTwo AUX Input
• Compatibility: ActiveTwo, BioSemi
• Packaging: One Photo Sensor (ActiveTwo) per pack

Application Note

1. Attach the photo sensor with dark duct tape to the screen or monitor where the visual stimulus is presented.
2. Plug the DIN type plug into the Ergo input on the front of the ActiveTwo EEG system.
3. Turn on the ActiveTwo, connect to the computer and run ActiView.
4. Add the photo sensor under the Auxiliary Sensors tab.