Is it normal to observe a sinusoidal signal of amplitude of up to 5V and frequency 50hz at the output of the electrodes when touched with hands? Note that the electrodes are Elecrodes are powered using a 4,97V DC voltage. As you can see in the pictures sent to you by email and which I couldnt post here, the scope shows a sinusoidal signal between 0V and 5V when we touch the electrodes with our hands and an approximatively DC 5V if electrodes are not in contact with anything. We are surprised of this important voltages at the output of amplifiers. Documents mentioned a gain of one.
We would like you confirm this behaviour and get an explanation of the reasons behind it.