Making Physiology Happen

ETH-3100 Intracellular Electrometer with Headstage


The iWorx ETH-3100 Intracellular Electrometer is a simple to use, low cost intracellular amplifier. It comes equipped with a small and light weight probe measuring 1.1cm in diameter by 5.6cm long and weighing only 10 grams.  The dual-transient control provides extremely precise adjustments to transient suppression during membrane recordings. The DC balance control eliminates the need for an external bridge or a differential input oscilloscope. The DC offset provides electrode offset control up to ±1V. An internal square-wave generator supplies a 100Hz current pulse to determine electrode resistance. It is also useful to adjust capacitance compensation. Capacity compensation can adjust up to 35pF of electrode capacitance. Additional stray capacitance can be reduced by using the driven shield connector on the head stage probe.

The ETH-3100 has an advanced capacitance “Ringer” control for clearing electrode tips and enhancing the membrane penetration of neurons. The Ringer’s amplitude (0 – 10V biphasic) and frequency (2 – 8kHz) of the pulsed oscillations sent to the electrode can be adjusted on the front panel.

A six position low pass filter and a 60Hz notch filter are available for the researcher to diminish extraneous frequencies and external line noise.

The current injection system allows for both internally generated current and externally generated current. This current can be set for continuous or momentary injection. The sum of the current can be gated by an external TTL logic signal source.

The small size of the amplifier and its remote power supply offers the advantage of placing the amplifier near to the experimental set up. For example, the amplifier can be placed within a Faraday cage with minimal power-line interference.


ETH-3100 Specifications

Noise (10Hz – 50kHz): 18µV, rms shorted; < 350µV, 20MΩ source 
Input impedance: 1013Ω; capacitance adjustable to zero
Bias current: Adjustable to zero 
Voltage gain: x1 and x10 
Capacity compensation: – 4pF – 35pF
DC Offset: ±1V 
Max internal current: 1µA 
External current: 100nA/V; 10V maximum 
Electrode test: 100Hz, 10 nA; (i.e. 10mV/MΩ electrode resistance)
Ringer: 0 – 10V biphasic, 2 – 8kHz 
Power: External power supply for low noise

Part Number: ETH-3100

Manual: ETH-3100