To check the EEG amplifier performance you can use calibration (test) signal mode. In this mode the Mitsar-EEG switches EEG amplifiers inputs to the internal square wave generator 1,0 Hz frequency and 100uV amplitude.
Data input from the sensors functionally differs from the calibration signal input only by the input signal source switching circuit. The obtained test signal should look as follows:
Test procedure:
Disconnect all sensors and electrodes from the Amplifier inputs.
Choose Monopolar Montage with REF as a reference.
Start calibration signal input.
WinEEG: Recording – Turn On (Off) Calibration…
EEGStudio: Add-on tab – Test button
Record a fragment of 15-20 sec.
Set software filters parameters as follows:
DC(0Hz) for HF
150 Hz for LF
Off for Notch
To measure obtained signal amplitude mark a small area around impulse front with markers as shown on the picture. Place the markers as close as possible to the impulse front
Measure the signal amplitude. It should be within 100 uV ±10%.
To measure the signal frequency, it is necessary to mark several impulses with the markers and start measurement. The frequency should be within 1,0 Hz±10%.
Calibration signal. Dash lines shows how to place markers to measure amplitude.Calibration signal parameters measurement
If the calibration signal parameters are different from listed above, please, contact your supplier or Mitsar.