The VA-10X is a sensitive (picoampere range) current amplifier that is intended for voltammetric measurements with carbon-fiber microelectrodes in biological systems, where the total currents do not exceed 100 nA.
It was designed at the Max-Planck-Institute for Experimental Medicine in Göttingen as an economically priced alternative to do-it-yourself systems and expensive commercial systems.
It can be used for DC amperometry, using either the built-in voltage source, or a user-supplied external voltage waveform (e.g. for cyclic voltammetry).
The VA-10X, with carbon-fiber disk electrodes having diameters of 10 µm or less is ideally suited for measurements from single cells plated onto glass cover slips. It can, however, also be used for measurements taken from superficially located cells in tissue slices. The VA-10X is not recommended for use in in vivo recordings with carbon-fiber electrodes having long cylindrical measuring surfaces, because in this case currents approach the µA range.
Input voltage range: ±1200 mV
Operating voltage: ±12 V
Enclosure: Size: 40 x 70 x 20 mm, grounded
Mounting plate: 50 x 70 mm, not conducting
Electrode connector: BNC with driven shield
Ground connector: 1 mm connector (black)
Driven shield output: 1 mm connector (red)
Input resistance: >10E+13 Ω
Current range: ±12 nA into 100 MΩ
2-pole or 4-pole Bessel FILTER (1-pole or 8-pole Bessel FILTER on request)
16 corner frequencies: 20, 50, 100, 200, 300, 500, 700, 1k, 1.3k, 2k, 3k, 5k,
8k, 10k, 13k, 20k Hz.
The VA-10X is delivered with standard headstage, cable set and connectors
for electrode connection and ground and a user manual.
GAIN: 7-position rotary switch (x0.5, x1, x2.5, x5, x10, x25, x50 mV/pA)
VOLTAGE SOURCE: COMMAND VOLTAGE set by 10-turn potentiometer, range: (1000 mV, polarity switch (+, 0, -), display XXXX mV
OUTPUTS: Impedance: 250 Ω
FILTERED: BNC connector, sensitivity selectable with GAIN switch,
FILTERED with LP Bessel FILTER
UNFILTERED: BNC connector, sensitivity selectable with GAIN switch
INPUTS: Resistance: 1 MΩ
INPUT BNC connector, sensitivity: /10, also displayed
DIMENSIONS: 19" rackmount cabinet, 483 mm, 250 mm, 88 mm
POWER REQUIREMENTS: 115/230 V AC, 60/50 Hz, fuse 0.4/0.2 A, slow