Warner OC-725C, User Manual

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16
Publication 5720-001 REV1.0
Using the Model Membrane
The model cell supplied with the OC-725C can be used for two purposes. First, novice
users will find it a convenient tool for gaining experience in the operation of the
instrument. Additionally, it is a convenient tool for trouble shooting since the function of
the instrument can be quickly checked.
A schematic of the model cell is shown below. The oocyte is represented by a 1 MΩ
resistor shunted by a 0.47 µF capacitor. The voltage and current electrodes are each
represented by 1 MΩ resistances and the bath probes are represented by the 10 kΩ
resistors.
Initial Instrument Settings
Connect the model cell to the OC-725C as shown on its cover. Be sure to connect the
ground wire to the ground mini-jack on the side of the bath probe. Connect the Vm x10
BNC and the I MONITOR BNC on the OC-725C to an oscilloscope.
Set the instrument panel controls as follows and turn the POWER SWITCH on.
Control Control block Setting
power switch Off
V
m
offset voltage
electrode
Center of rotation
(Approximately 5 turns)
output gain bath electrodes
0.1 V/µA
gain select bath electrodes
x1.0
clamp mode switch clamp
Off
dc gain toggle clamp
Out
gain clamp CCW to detent
off
hold potential commands
00 mV
hold potential multiplier commands
x1.0
hold polarity commands
Off
V
e
Offset current
electrode
Center of rotation
(Approximately 5 turns)