A-M Systems 1800 Handbuch - Seite 8
Blättern Sie online oder laden Sie pdf Handbuch für Verstärken A-M Systems 1800 herunter. A-M Systems 1800 14 Seiten. Microelectrode ac amplifier
Seite drucken
Typical Set-Up Procedure
The Head Stage Probe is used to connect the extracellular electrodes to the amplifier.
The 4 inch Connector Cables can be used to connect the Probe inputs to electrodes
which have standard gold male pin connectors. The
the amplifier should be used as the system ground in the particular recording medium
(e.g. bath or animal ground). Note: Either the Head Stage
the front panel must be connected to provide a return current path. If neither ground is
connected the Head Stage Amplifier will saturate and no signal will be measured.
Care should be taken to keep the power cables from all instruments as far away as
possible from the recording set-up. Proper grounding and shielding techniques
should be used to insure a minimum of interference.
Recording
The
switch should be placed in the
MODE
Filter, and
CUT-OFF
the signal to be recorded. The
connector is less than ±10 V, otherwise higher and/or lower portions of the
OUTPUT
signal may appear cut-off or flattened.
Stimulating
When the
switch is placed in the
MODE
monitored by measuring the voltage (V) across an internal, fixed resistor (R = 1 kV)
in series with the electrodes. Since I=V/R and R is known, the voltage is a measure
of the stimulus current. The internal resistor is in series with the indifferent lead
(
) so that excessive voltages do not appear at the Probe Amplifier inputs.
PROBE-
Therefore, to ensure that the current in the indifferent lead is equal to and opposite of
that in the active lead, only isolated stimulus sources should be used. The shield of
the stimulation cable is not internally grounded in the amplifier and needs to be
grounded at the connection to the stimulator. When an isolated stimulator is used
the
connector must be grounded to function properly.
PROBE-
Checking Electrode Impedance
When the
switch is placed in the
MODE
be checked. In this mode, an internal oscillator automatically passes a 0.1 µA, 1 kHz
sine-wave current (I) through the electrode, and the probe amplifier monitors the
resultant voltage (V) that develops across the electrode. Since R=V/I and I is known,
the monitored voltage is a measure of the electrode impedance.
A-M Systems
131 Business Park Loop, P.O. Box 850 Carlsborg, Wa 98324
Telophone: 800-426-1306 * 360-683-8300 * FAX: 360-683-3525
E-mail: [email protected] * Website: http://www.a-msystems.com
Operating Instructions
Filter should be set according to the frequency content of
NOTCH
Switch should be set so that the signal at the
GAIN
connector on the front panel of
GND
position. The
REC
position, stimulation current (I) is
STIM
position, the impedance the electrode can
IMP
or the
PROBE GND
GND
Filter,
LOW CUT-OFF
on
HIGH
4