Enter Electrochemical Inputs
Plotly Graph
The chart compares total IR drop against remaining drop after compensation over a current sweep.
Example Data Table
| Run | Current (mA) | Total Resistance (Ω) | IR Drop (V) | Compensation (%) | Remaining Drop (V) | Comment |
|---|---|---|---|---|---|---|
| Cell A | 10 | 12.0 | 0.1200 | 80 | 0.0240 | Moderate drop with strong compensation. |
| Cell B | 25 | 8.5 | 0.2125 | 70 | 0.0638 | Noticeable error remains at higher current. |
| Cell C | 50 | 4.2 | 0.2100 | 50 | 0.1050 | Half compensation still leaves large distortion. |
| Cell D | 80 | 2.6 | 0.2080 | 90 | 0.0208 | Low resistance helps maintain target potential. |
Formula Used
In electrochemistry, IR drop represents voltage lost across resistive parts of the cell. The calculator can use either a measured uncompensated resistance or a geometry-based estimate from conductivity, spacing, and area.
Effective potential is especially useful when checking whether the working electrode actually experiences the intended voltage after compensation is applied.
How to Use This Calculator
- Choose Derived mode when you know conductivity, spacing, and area.
- Choose Direct mode when you already measured uncompensated resistance.
- Enter current and select the correct unit.
- Provide the applied potential used for your experiment.
- Enter the percentage of IR compensation already applied by your setup.
- Add extra series resistance if leads, fixtures, or connectors matter.
- Press Calculate IR Drop to see the results above the form.
- Review the chart, summary table, and error percentage.
- Use the export buttons to save the results as CSV or PDF.
Frequently Asked Questions
1) What is IR drop in an electrochemical cell?
IR drop is the voltage lost when current passes through cell resistance. It reduces the real electrode potential and can distort polarization, plating, corrosion, and sensing measurements.
2) Why is IR drop important in chemistry experiments?
It affects how much voltage actually reaches the interface. Large IR drop can shift reaction conditions, alter kinetics, and produce misleading conclusions about catalytic or electroanalytical performance.
3) When should I use direct resistance mode?
Use direct mode when you already measured uncompensated resistance using EIS, current interrupt, or another instrument method. It is usually better than estimating from geometry alone.
4) When is derived geometry mode useful?
Use derived mode during design work, quick estimates, cell comparisons, or early planning. It helps when conductivity, spacing, and active area are known but measured resistance is unavailable.
5) Can I set compensation to 100 percent?
You can model it, but real instruments often avoid full compensation because overcompensation may cause oscillation or instability. Many setups use partial compensation for safer control.
6) What does current density tell me?
Current density normalizes current by area. It helps compare electrodes fairly, predict heating or concentration gradients, and evaluate whether a given surface is being driven too hard.
7) Can this calculator handle negative current?
Yes. Signed current is preserved in the calculation. That lets you inspect anodic and cathodic directions while still viewing the resulting drop, effective potential, and chart trend.
8) Should I include lead and contact resistance?
Yes, when those resistances are not negligible. Extra series resistance can materially increase voltage loss, especially at higher currents, so including it improves practical accuracy.