Most people looking for a potentiostat want to know what one is. You are probably past that point. You have a working setup, and something about it has started to get in the way — the noise floor, the current ceiling, the number of cells you can run before Friday, or software that will not let you script what you actually want to measure.
This page is about the specifications that begin to matter once the basics are settled, and which instruments in the PalmSens range are built for that end of the scale.
Where a standard potentiostat runs out
An entry-level instrument covers the middle of electrochemistry comfortably. Cyclic voltammetry on a millimetre electrode, a corrosion sample in a beaker, a calibration curve for a sensor — none of that asks much of the hardware.
Research pushes outward from that middle in four directions, and each one has its own wall. Currents get smaller, until the signal disappears into the instrument’s own noise. Currents get larger, until the potentiostat cannot supply them. Impedance measurements need a wider frequency window than the frequency response analyser offers. And the number of experiments grows past what one channel can run in a working week.
Knowing which wall you are actually hitting is most of the decision. The sections below take them one at a time.
Measuring at the femtoampere level
Microelectrodes, single-entity electrochemistry and biosensors at clinically relevant concentrations all produce currents in the picoampere range or below. At that scale the question is no longer whether the instrument can measure the current, but whether it can distinguish it from its own noise.
The lowest current range on PalmSens4, MultiPalmSens4 and Nexus is 100 pA, with a measured resolution of 0.005% of the range — 5 fA on that lowest range. Current accuracy is specified as better than 0.2% of the current, plus 10 pA, plus 0.1% of the range.
Hardware is only part of it at this level. A Faraday cage, short and shielded leads and galvanic isolation between the instrument and anything else touching the cell will usually do more for your baseline than another decade of nominal sensitivity.
At the femtoampere level, your cabling is part of the instrument.
Driving cells that need amps, not milliamps
Coin cells, electrolysers, fuel cells and large-area coated coupons ask the opposite question. Here the limit is how much current the potentiostat can source, and how much voltage it can put across the cell while doing it.
A portable research instrument such as PalmSens4 delivers up to ±30 mA at a compliance voltage of ±10 V. That covers a great deal of sensor and corrosion work, but not a cell that wants to be cycled at a full ampere.
Nexus is the instrument for that end: ±1.1 A maximum current across eleven current ranges from 100 pA to 1 A, with ±12 V compliance and a ±10 V applied potential range. It is the same span of low-current sensitivity, with two and a half extra decades on top.
Impedance across ten decades of frequency
Electrochemical impedance spectroscopy is where instrument bandwidth shows up most directly in your data. PalmSens4 and MultiPalmSens4 are available with either a 100 kHz or a 1 MHz frequency response analyser, chosen as a hardware option when the instrument is ordered, while Nexus covers 10 µHz to 1 MHz as standard.
Which of those limits actually matters for your measurement, along with how to choose the amplitude and whether to measure potentiostatically or galvanostatically, is covered in detail in electrochemical impedance spectroscopy.
More than one working electrode
A three-electrode cell is the default, not a limit. Rotating ring-disk work, generator–collector experiments and scanning setups all need a second working electrode under independent control, and the bipotentiostat module adds one to PalmSens4, MultiPalmSens4 and Nexus.
On MultiPalmSens4 this extends further. The channels can be tied to electrodes in a single cell and driven in step, which turns a multi-channel instrument into a polypotentiostat — an array of working electrodes sharing one reference and one counter electrode.
Where the array gets larger, a MUX8-R2 multiplexer takes over: eight working electrodes on one instrument, switched in milliseconds, and up to eighty channels when it is combined with MultiPalmSens4.
Four-electrode measurements sit in the same category: liquid–liquid interfaces, ion-selective membranes and flow cells where the current path and the potential measurement need to be separated.
Several working electrodes in one cell, with hardware synchronisation across the channels.
Multiple working electrodes in one cell
The step from one working electrode to several is easier to watch than to read about. This walkthrough builds the setup in a single cell and synchronises the channels in hardware.
That second part is what starts to matter once the array grows. Software timing drifts between channels while a shared hardware trigger does not, and at short timescales that difference lands straight in your data.
Running experiments in parallel
Beyond a certain point the bottleneck is not sensitivity, it is calendar time. Replicates for statistics, a screening series across electrode materials, or a battery cycling protocol that runs for weeks will all occupy an instrument far longer than the experiment itself is interesting.
MultiPalmSens4 is built for this, with 4 – 10 channels that can run independently, simultaneously, or synchronised. Each channel is configured on its own: potential range, EIS bandwidth, bipotentiostat module, iR compensation and galvanic isolation are all per-channel choices, so a ten-channel instrument does not have to be ten identical instruments.
MultiEmStat4 covers the same idea at a lower price point, and Nexus units can be stacked when you want several high-current channels rather than many low-current ones.
Controlling the instrument from your own code
Advanced work usually means the potentiostat is one component in a larger setup — a pump, a stage, a spectrometer, a robot, a script that decides the next potential based on the last result.
PSTrace and MultiTrace cover manual and scheduled measurement, and the SDKs open the instrument up to Python, MATLAB, LabVIEW and .NET. MethodSCRIPT goes a step further by running the measurement sequence on the instrument itself, so timing does not depend on the computer or the connection.
That matters for embedded and field deployments, where the instrument has to keep its timing without a PC attached.
Comparing the research instruments
Four instruments cover the research end of the range, and which one fits depends entirely on which limit your experiment runs into first.
| Specification | PalmSens4 | Nexus | MultiPalmSens4 | EmStat4X |
|---|---|---|---|---|
| Channels | 1 | 1, stackable | 4 – 10; up to 80 switched cells with MUX8-R2 | 1 |
| Applied potential | ±5 V or ±10 V | ±10 V | ±5 V or ±10 V per channel | ±3 V (LR) / ±6 V (HR) |
| Potential resolution | 76.3 µV (18-bit) | 76.3 µV (18-bit) | 76.3 µV (18-bit) | 100 µV (LR) / 183 µV (HR) |
| Compliance voltage | ±10 V | ±12 V | ±10 V | ±5 V (LR) / ±8 V (HR) |
| Current ranges | 100 pA – 10 mA (9) | 100 pA – 1 A (11) | 100 pA – 10 mA (9) | 1 nA – 10 mA (8, LR) / 100 nA – 100 mA (7, HR) |
| Maximum current | ±30 mA | ±1.1 A | ±30 mA | ±30 mA (LR) / ±200 mA (HR) |
| EIS / FRA range | 10 µHz – 100 kHz or 1 MHz | 10 µHz – 1 MHz | 10 µHz – 100 kHz or 1 MHz | 10 µHz – 200 kHz |
| Second working electrode | BiPot module | BiPot module, WE2 to ±45 mA | BiPot module, per channel | Not available; MUX8-R2 switches up to 8 WEs |
| Internal storage | 16 GB, approx. 1.6M measurements | 32 GB, over 800M data points | 16 GB per channel, approx. 1.6M measurements | 500 MB, over 15M data points |
| Size and weight | 15.7 × 9.7 × 3.5 cm, approx. 500 g | 20 × 21 × 4.5 cm, 1.8 kg | 15 × 25 × 25 cm, approx. 4 kg | 11.4 × 8.0 × 4.5 cm, approx. 500 g |
| Portable | Battery, USB and Bluetooth | No, mains powered | No, mains powered | Battery, USB-C or wireless |
Specifications as published in the PalmSens product brochures and product pages.
What a research-grade potentiostat costs
PalmSens publishes specifications in full and quotes per configuration, because on the multi-channel instruments the configuration is genuinely yours to make — channel count, potential range, EIS bandwidth and modules all change the price.
Send the outline of your experiment rather than a model name, and the quotation will come back against what you actually need to measure.
Related pages
- Multi-channel potentiostat — running several cells in parallel
- Portable potentiostat — battery-powered measurement outside the lab
- Economical potentiostat — where budget leads the choice
- Bipotentiostat — a second working electrode under independent control
- Which potentiostat do I need? — the full selection guide
Frequently asked questions
What makes a potentiostat suitable for advanced research?
Four specifications decide it in practice: the lowest usable current range, the maximum current and compliance voltage, the EIS frequency window, and whether the software can be driven from your own code. Everything else follows from those.
What is the lowest current a PalmSens potentiostat can measure?
The lowest current range is 100 pA, with a measured resolution of 0.005% of the range — 5 fA. Reaching that in practice depends as much on shielding and cabling as on the instrument.
Which PalmSens instruments reach 1 MHz EIS?
Nexus as standard, and PalmSens4 and MultiPalmSens4 in their 1 MHz FRA configuration. The 100 kHz configuration is the alternative, and on MultiPalmSens4 the choice is made per channel.
Can I control a potentiostat from Python or MATLAB?
Yes. SDKs are available for Python, MATLAB, LabVIEW and .NET. MethodSCRIPT additionally runs the measurement sequence on the instrument itself, which keeps timing independent of the computer.
What is the difference between a bipotentiostat and a polypotentiostat?
A bipotentiostat controls two working electrodes independently against one reference and counter electrode. A polypotentiostat extends the same principle to more working electrodes — on MultiPalmSens4 by tying several channels to electrodes in a single cell.
Do I need a multi-channel instrument or several single-channel ones?
Separate instruments give you independent setups in different places. A multi-channel instrument gives you synchronised starts, one software environment and the option of polypotentiostat mode. If the experiments belong to one study, the multi-channel route usually wins.
How much current does battery research need?
It depends entirely on cell format. Coin cells and small pouch cells are often served by tens of milliamps, so PalmSens4 is enough. Larger formats and higher C-rates move into the ampere range, which is Nexus territory.