Dagan IX2-700 Instrukcja obsługi - Strona 6

Przeglądaj online lub pobierz pdf Instrukcja obsługi dla Wzmacniacz Dagan IX2-700. Dagan IX2-700 14 stron. Dual intracellular preamplifier

IX2-700 Dual Intracellular Preamplifier

OFFSET VOLTAGE CONTROL

This control cancels electrochemical potentials developed between reference

electrodes and the probe input. Offsetting the output level of the amplifier nulls

these potentials. The range is ±200 mV. Be careful not to touch this control during

the experiment, as it will change the baseline.

ELECTRODE IMPEDANCE TEST (Z TEST)

This switch provides a rapid check of electrode impedance. When switched

on, the square wave signal proportional in amplitude to the electrode impedance,

appears at the 10 VmBNC connector. A signal level of 1 mV is equivalent to 1

Megohm of electrode resistance when using a X1 headstage. A X.1 (i.e., divide by

10 headstage) scales this to .1 mV per megohm referred to the input.

DC CURRENT 10-TURN DIAL

The current dial provides a depolarizing (positive) or hyperpolarizing

(negative) current selected by the corresponding Positive/Off/Negative polarity

switch. The range of the current is 100 nA full scale times the headstage multiplier.

Thus, the X .1 headstage would change the full scale dial reading to 9.99 nA. The

current control is linear and the readout corresponds to the actual current selected.

This current is algebraically added to the currents produced by the EXT I BNC

connector and also the Step Current Command Generator, if selected.

BRIDGE BALANCE CONTROL

The bridge Balance Control is used to null out the effects of stimulus current

passing through the recording electrode. The bridge is balanced by turning the

knob on the dial housing. When the bridge is balanced the voltage seen at the

10Vm connector will be nulled to zero and the resistance of the electrode and cell

membrane is read on the dial. The range of the bridge balance dial is 100

Megohms divided by the probe current multiplier. Thus, for the X.1 probe, the

range will be 1000 Megohms. The bridge Balance is disabled when Z Test is used.

STEP CURRENT 10-TURN DIAL

The step current adds to the Holding Current and has ten times the range. It

can be on continuously, if gated on and off by a greater than 3 volt level supplied

to the Gate BNC connectors.