ActiveTwo Skin Conductance Module (Includes Required Amplifier/Converter Channels) With this ActiveTwo accessory, the conductance of the skin can be measured. The SC option consists of two passive electrodes to induce an oscillatory signal exactly synchronized with the system's sample-rate. The skin conductance option is wired to one of three available circular DIN connectors on the ActiveTwo front panel. Because the skin conductance accessory uses "lock-in detection", the stimulus-current can be as low as 1uA. The low-current and synchronized oscillator ensure that the biopotential measurements (EEG, EMG or ECG) are not corrupted by the skin conductance oscillator signal. In ActiveTwo models produced before June of 2005, these couplers were configured to measure skin resistance. ActiView software version 5.35 or later automatically identifies whether the ActiveTwo system has a 16 Hz or 512 Hz coupler. To check which model you have, setup the ActiveTwo system and start the ActiView software to view incoming data for a few seconds. Then, select the "Auxiliary Sensors" tab, and check the "GSR units" indicator in the left sidebar:
Unit = Ohm means a 512 Hz GSR coupler is installed, and your AD box motherboard will need to be retrofitted before this accessory can be installed. Unit = nanoSiemens means a 16 Hz skin conductance coupler is installed, and no ADC motherboard retrofitting will be needed for this accessory to work with your AD box.