With the CHI200(B) Picoamp Booster and Faraday Cage, current down to a few picoamperes can be readily measured. The CHI200 is compatible with the Model 600/A, 700/A series of instruments, while the CHI200B is compatible with Model 600B/C/D, 700B/C/D and 800B/C series. When used with a 700/A/B/C/D and 800B/C series bipotentiostat, the Picoamp Booster will affect the primary channel only.

The internal sensitivity of the 600B/C/D series is the same as the Picoamp Booster (1x10^-12 A/V). However, the bias current of the 600B/C/D series input can be as high as 50 pA. The Picoamp Booster has lower bias current, and it also brings the preamplifier close to the electrode hence resulting in lower noise. The Faraday Cage also makes it possible to make relatively fast measurements of small currents.

When the Picoamp Booster is connected and the sensitivity scale is at or below 1x10^-8 A/V, the Picoamp Booster will be enabled. Otherwise, it will be disabled. The instruments automatically sense whether a Picoamp Booster is connected. The enable/disable switching is also automatic.

The Picoamp Booster will be disabled for techniques using automatic sensitivity switching, such as Tafel plots and bulk electrolysis (BE). However, it works with AC impedance (IMP). However, for galvanostatic techniques, such as chronopotentiometry (CP), chronopotentiometry with Current Ramp (CPCR), Mulit-Current Steps (ISTEP), and potentiometric stripping analysis (PSA), the Picoamp Booster will not work.

Besides allowing weak signal measurements, the Faraday cage is useful for eliminating electrical interference, especially line frequency noise. If the electrochemical cell is picking up electrical noise from the environment, the additional use of the Faraday cage is strongly recommended.

Cyclic voltammogram at an ultramicroelectrode

Differential pulse voltammogram at an ultramicroelectrode.

With the CHI680B Amp Booster, the current can be measured up to 2 A. The CHI680 is compatible with Model 600, 600A, 600B, 600C and 600D series of instruments. You can stack the CHI600/A/B/C/D and the CHI680B together. The CHI680B can also be connected to the model 700B/C/D series, but it will only work for the primary channel.

With the Amp Booster connected, the cell control signals such as purge, knock and stir are disabled.

The Amp Booster will also allow low current measurements. You may need to use the Faraday Cage to eliminate line frequency noise when the scan rate is above 50 mV/s.

The frequency response of the Amp Booster is somewhat lower than that of the CHI600/A/B/C/D instruments. For high speed experiments, the Amp Booster should be disconnected.

Dimension: 12.5”(W) x 11”(D) x 4.75”(H)

Weight:  18 Lb.

CHI684 is a multi-channel multiplexer for the model 400/A/B, 600A/B/C/D, 700A/B/C/D, 800B/C, 900B/C and 1100A/B series. The multiplexer switches four lines (working, sensing, reference, and counter for a single potentiostat, second working, reference and counter for a bipotentiostat). You can have up to 64 cells, but only one cell can be connected at a time.

The multiplexer is controlled from the "Multiplexer" command under the Control menu. You can select any channel and run experiments for a sequence of the selected channels. Data files will automatically be saved after each run. You can also be prompted before each channel run.

Arbitrary channels can be set immediately. An experiment can then be run for that particular channel.

Two Macro commands are available for the multiplexer. One is "mch:##". It allows the user to choose an individual channel. The other macro command is "mchn". This is used in a For...Next loop to select the channel according to the For...Next loop counter.

The minimum number of channels for the CHI684 is 8. The channel increment is 8. The maximum number of channels is 64.