Choosing ESD Measurement Electrodes - which do I need?
Without the correct measurement electrode there is no compliant resistance test on ESD floors, table mats or gloves. This guide explains the 5-pound electrode and the two-point electrode, the matching test cables and the correct test voltage per IEC 61340-2-3 and IEC 61340-4-1.
View measurement electrodesWhich measurement electrodes exist and what are they for?
For resistance testing on ESD surfaces there are two standard electrodes: the 5-pound electrode (point electrode) and the two-point electrode. Both define a fixed contact area and a fixed contact pressure so that readings stay reproducible and compliant.
The 5-pound electrode has a standardised weight of 2.27 kg (5 lb) and a conductive rubber foot of about 63.5 mm diameter. You use it to measure resistance from one point to ground (Rg) or point to point (Rp) by placing two electrodes at a defined distance.
The two-point electrode combines two spring-loaded contacts in a handheld probe. It suits small items such as gloves, finger cots, packaging or narrow work surfaces where a 5-pound electrode cannot be set up sensibly.
Which standards and test voltages apply?
The test methods are set in the IEC 61340 series. IEC 61340‑2‑3 covers resistance measurement of planar materials, IEC 61340‑4‑1 the testing of floor coverings and IEC 61340‑4‑5 the combined system of floor and person. Electrodes must meet exactly these requirements for weight, contact area and contact pressure.
The test voltage is matched to the expected resistance: 10 V for low resistances below roughly 10⁶ Ω and 100 V for higher resistances above that. A compliant meter supplies both voltages and limits the current safely.
- IEC 61340‑2‑3: resistance and resistance measurement of planar materials.
- IEC 61340‑4‑1: electrical resistance of floor coverings and installed floors.
- IEC 61340‑4‑5: characterisation of the person plus footwear plus floor system.
- IEC 61340‑5‑1: overarching requirements for the ESD control programme.
Which cables and accessories do you need?
An electrode is only as good as its connection. For compliant measurements you need well-insulated test leads with matching plugs, usually 4 mm banana plugs or crocodile clips, plus a ground cable to the common point of the workstation.
The cables should be low-resistance in the conductor but cleanly insulated so they do not distort the reading. Leads that are too long or damaged, with high contact resistance at the terminals, are a frequent source of error. Check cables and clips regularly for a firm fit and bright, oxide-free contacts.
Frequently asked questions
Why does the point electrode weigh exactly 5 pounds?
The standardised weight of 2.27 kg (5 lb) produces a defined contact pressure on the conductive rubber surface. Only then are contact resistance and reading reproducible and comparable with other test sites.
When do I use 10 V and when 100 V test voltage?
Use 10 V for resistances below about 10⁶ Ω and 100 V for higher resistances above that. A compliant ESD meter offers both voltages and often selects them automatically.
Can I use a two-point electrode for the floor?
Floor testing per IEC 61340‑4‑1 requires the 5-pound electrode. The two-point electrode is intended for small items such as gloves and packaging, not as a substitute for the floor measurement.
How often should electrodes and meter be calibrated?
The meter is usually calibrated annually, while the electrodes are checked for cleanliness and rubber condition before every series. A test resistor confirms the system on site.
Looking for the right ESD measurement electrodes?
We supply 5-pound electrodes, two-point electrodes, test cables and calibration resistors for compliant measurements per IEC 61340.
Standard-compliant
Electrodes to IEC 61340-2-3 and 4-1.
Defined values
2.27 kg weight and a verified electrode foot.
Calibratable
Matching test resistors for every measuring series.
Expert advice
ESD specialists help you choose.