Electric field meter

Electric Field Meter

Measuring Electric Field Strength

The measurement of electric fields and field strength is one of the most important measurements in ESD metrology. An electric field meter should therefore be part of the standard equipment in any EPA. An electric field meter – also referred to as an electrostatic fieldmeter, rotating voltmeter or field mill – is a device for measuring electric field strength. At a defined measurement distance from an object, it can be used as a voltage measuring instrument.

Electric Field Meter – Operating Principle and Measurement Method

Electric field meters measure electric field strength without contact over a defined distance to the measurement surface. The measurement principle is based on detecting the electric field emanating from charged surfaces, materials or components. With a known and constant measurement distance, the surface potential in volts can be derived directly from the measured field strength – without physical contact with the measurement object. This non-contact method makes the electric field meter particularly suitable for measuring sensitive components, insulating surfaces and moving materials in production environments. In technical literature, the device is occasionally also referred to as a field mill – a term derived from the rotating measurement principle of older device generations.

Applications in ESD Metrology

Electric field meters are used in EPA areas for the following measurement tasks:

• Ioniser verification – Measurement of offset voltage and evaluation of neutralisation performance per ANSI/ESD SP3.3.
• Detection of charged materials – Identification of insulating or insufficiently dissipative surfaces in production.
• Packaging inspection – Measurement of electrostatic charges on ESD packaging and transport equipment.
• Workstation analysis – Assessment of electrostatic risks at assembly and test workstations.
• Process monitoring – Continuous monitoring of electrostatic fields in automated production lines.

Electric Field Meter – Selection by Requirement

The choice of the appropriate electric field meter depends on the measurement range, required accuracy and operating environment. Handheld devices are suitable for mobile measurement tasks in the context of EPA audits and routine inspections. Stationary electric field meters are used for permanent process monitoring. For combined measurement tasks – such as the simultaneous recording of field strength and ioniser performance – use within an ESD Audit Kit is recommended. All electric field meters in the ESD-PROTECT range are aligned with the requirements of DIN EN 61340-5-1 and ANSI/ESD S20.20 and can be calibrated in the in-house test laboratory.