g.tec medical engineering GmbH
g.USBamp, USB Biosignal Amplifier: Instruction for use
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V2.16.09
Page 17
Calibrating g.USBamp
In calibration mode, all electrode input sockets are disconnected from the input amplifiers. Additionally
an internally generated sine wave with amplitude of
10 mV and 10 Hz is connected to the input
amplifiers.
Impedance measurement
In impedance measurement mode, sequentially to each electrode an internally generated sine wave
with
10 mV and 20 Hz is applied. The voltage loss is measured and transmitted via USB to the PC.
NOTE: The ground electrode must be connected to group D if the impedance is measured for all
groups.
Shortcut of inputs
A TTL high impulse on the SC input socket can be used to disconnect all electrode input sockets from
the input amplifiers and to connect the inputs to ground potential.
Synchronization of multiple g.USBamps
On socket SYNC OUT the digital converter clock rate can be measured. On SYNC IN it is possible to
apply the clock signal for the digital converters.