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PD IEC 61340 — Electrostatics Measurement of Chargeability Technical Report (PD IEC 61340-2-2:2000)
PD IEC 61340-2-2:2000 — Electrostatics — Part 2-2: Measurement Methods — Measurement of Chargeability（IEC TR 61340-2-2:2000）
⚡ PD IEC 61340-2-2:2000 is a British Standards Institution (BSI) Published Document (PD) reproducing verbatim the IEC Technical Report IEC TR 61340-2-2:2000 “Electrostatics – Part 2-2: Measurement methods – Measurement of chargeability”. Part of the IEC 61340 electrostatics series, it specifies measurement methods for the chargeability of materials, focusing on Faraday pail measurement of the electrostatic charge characteristics of powders, particles and bulk materials under mechanical action. It is a foundational measurement technical document for electrostatic control in electronics, chemical, pharmaceutical and powder-processing industries.
💡 Chargeability describes a material’s ability to accumulate electrostatic charge during mechanical processes such as friction, flow and pouring. Accurate chargeability measurement is essential for assessing electrostatic discharge (ESD) risk, designing anti-static processes and selecting suitable anti-static materials.
1. Report Overview and Series Positioning 📌
This article is the summary review for the “PD IEC 61340” prefix of the BSB223 batch. The report in this batch is PD IEC 61340-2-2:2000 (identical to IEC TR 61340-2-2:2000, first edition, 2000-07). BSI published it effective 15 November 2000 (ISBN 0 580 36666 9), with UK participation directed by the Electrotechnical Sector Committee and entrusted to Technical Committee GEL/101 (Electrostatics). The document states: “This PD is not to be treated as a British Standard.” ICS classification is 29.020 (electrical engineering).
| Batch Prefix | Standard | Title | Status |
|---|---|---|---|
| PD IEC 61340 | PD IEC 61340-2-2:2000 | Electrostatics – Part 2-2: Measurement methods – Measurement of chargeability | Reproduces verbatim IEC TR 61340-2-2:2000 |
The technical report body covers: General, Scope, Reference document, Fields of application, Test specimens and conditioning, and Methods of measurement. The measurement methods section focuses on the Faraday pail method, its principle, apparatus, procedure and results.
⚠️ This report is a Technical Report (TR), not a formal British Standard; the measurement methods given guide laboratory and engineering practice, and acceptance criteria for specific applications should be set by the relevant product specification or electrostatic control procedure.
2. Fields of Application and Basic Concepts 🔧
2.1 Fields of Application
The report specifies methods for measuring the chargeability of materials and objects, applicable to:
- Powders and particulate materials: such as polymer powders, chemicals, pharmaceuticals, pigments, etc.
- Bulk materials: electrostatic accumulation characteristics during pouring, conveying, fluidisation, etc.
- Material evaluation: providing quantitative evidence for material selection, process optimisation and electrostatic protection design.
2.2 Test Specimens and Conditioning
Test specimens should be prepared to the specified size, quantity and state, and conditioned in a controlled environment (specified temperature and relative humidity) to eliminate environmental effects and ensure reproducibility.
| Element | Content | Control Points |
|---|---|---|
| Specimen preparation | Size, mass, quantity | Representative samples per the method |
| Conditioning | Temperature and humidity equilibration | Record and control environmental conditions |
| Charge excitation | Mechanical action generating charge | Standardised pouring, fluidisation, friction, etc. |
| Charge measurement | Faraday pail or equivalent | Instrument calibration and electrostatic shielding |
3. Faraday Pail Measurement Method 🔥
3.1 Measurement Principle
The basic principle of the Faraday pail (Faraday cage) method: the test sample is placed inside a Faraday pail consisting of two nested conductors; the sample’s charge induces charge transfer between the outer and inner conductors via electrostatic induction; an electrometer (coulomb meter) connected to the inner pail measures the sample charge Q; combined with the sample mass m, the charge per unit mass (C/kg) – the material’s chargeability index – is obtained.
3.2 Apparatus Requirements
The report sets requirements for the measuring apparatus, mainly including: a Faraday pail (double-layer metal container, inner and outer pails electrically isolated with good electrostatic shielding), a high-input-impedance electrometer/coulomb meter, connection and grounding systems, and the associated sample handling and protection devices. The instrument should be calibrated regularly to ensure measurement accuracy.
3.3 Procedure and Results
The measurement procedure generally includes: sample conditioning – delivering the sample into the Faraday pail in the specified manner (e.g. pouring) – recording the electrometer reading – weighing the sample – calculating the charge per unit mass. Results are usually expressed as the mean and dispersion of multiple measurements, and attention should be paid to the significant influence of ambient humidity and sample moisture content on chargeability.
🚨 Electrostatic measurement requires very high insulation and shielding: any leakage in the measuring system or external electric field interference seriously affects the results; operators should also take anti-static measures (anti-static wrist straps, anti-static flooring) to avoid human-body static interference.
4. Engineering Application Points 🛠️
- 📋 Electrostatic risk assessment: use chargeability measurement to assess the ESD risk level of powder conveying, pouring, packaging and other operations.
- 🔍 Material selection: compare the chargeability of different materials to select anti-static materials with low charge accumulation and good suitability.
- 🛡️ Explosion and fire prevention: in combustible dust and flammable vapour environments, design grounding, humidification and ionisation controls based on chargeability data.
- 📊 Process optimisation: optimise conveying speed, pipe material and feeding method to reduce charge accumulation.
- 🌐 Standards linkage: use together with the IEC 61340 series (electrostatic protection, ESD of electrical/electronic equipment, etc.) to form a complete electrostatic management system.
✅ The IEC 61340 series is the authoritative international standard family for electrostatics. Measurement method standards (Part 2) combine with protection method standards (such as Parts 4 and 5) to form the complete “measure – evaluate – protect” technical chain, continuously supporting the electronics manufacturing, chemical and pharmaceutical industries.
5. Frequently Asked Questions ❓
❓ Q: What is chargeability?
A: Chargeability is a material’s ability to accumulate electrostatic charge under mechanical action such as friction, flow and pouring, usually expressed as charge per unit mass (C/kg).
A: Chargeability is a material’s ability to accumulate electrostatic charge under mechanical action such as friction, flow and pouring, usually expressed as charge per unit mass (C/kg).
❓ Q: What is the principle of the Faraday pail method?
A: The test sample is placed in a double-layer metal Faraday pail; the charge is transferred to the electrometer by electrostatic induction, and the mass charge density is calculated by combining the measured charge with the sample mass.
A: The test sample is placed in a double-layer metal Faraday pail; the charge is transferred to the electrometer by electrostatic induction, and the mass charge density is calculated by combining the measured charge with the sample mass.
❓ Q: Is this document a formal British Standard?
A: No. It is a BSI Published Document (PD) reproducing verbatim an IEC Technical Report, and the document states it “is not to be treated as a British Standard”.
A: No. It is a BSI Published Document (PD) reproducing verbatim an IEC Technical Report, and the document states it “is not to be treated as a British Standard”.
🔍 Q: What factors mainly affect the measurement results?
A: Ambient temperature and relative humidity, sample moisture content and preparation state, insulation and shielding of the measuring system, operating method and instrument calibration state.
A: Ambient temperature and relative humidity, sample moisture content and preparation state, insulation and shielding of the measuring system, operating method and instrument calibration state.
❓ Q: What is the practical use of measuring chargeability?
A: It is used for electrostatic risk classification, anti-static material selection, explosion/fire prevention process design and electrostatic protection system evaluation – the basis of electrostatic control.
A: It is used for electrostatic risk classification, anti-static material selection, explosion/fire prevention process design and electrostatic protection system evaluation – the basis of electrostatic control.