Static Honest Meter，JIS L1094

The Static Charge Decay Tester is an instrument used to evaluate the electrostatic decay characteristics of materials. Its primary purpose is to quantitatively measure how surface charges on a material diminish over time under static conditions. This type of equipment is widely used in material research and development, quality control, and standardized testing, and plays an important role in assessing the electrostatic performance of fibers, plastic films, textiles, and other materials. The term “honest” symbolizes that its measurement results are reliable, repeatable, and truly representative of the material’s electrostatic behavior.

Basic Concepts of Static Electricity and Electrostatic Decay

Static electricity refers to the accumulation of electric charges on the surface of insulating materials, usually generated through friction or separation between surfaces. In manufacturing, daily life, and industrial environments, static electricity can cause problems such as damage to sensitive electronic components, dust attraction, and spark discharge. Therefore, understanding how materials accumulate and dissipate static charges is crucial.

Electrostatic decay refers to the process by which a charged material gradually returns to an electrically neutral state after being ionized and charged. The speed and pattern of this decay reflect the material’s antistatic capability.

Core Testing Indicators

The Static Charge Decay Tester measures several key parameters related to the electrostatic decay process in order to evaluate a material’s antistatic performance:

1. Electrostatic Decay Time

This refers to the time required for the surface voltage of a charged material to drop from its initial value to a specified threshold (for example, 10% of the initial voltage). A shorter decay time indicates that the material releases static charges more quickly and has better antistatic properties.

2. Half-Life of Charge Decay

The half-life is the time it takes for the surface voltage to decrease to half of its original value. A shorter half-life means faster charge dissipation and stronger antistatic performance.

3. Electrostatic Decay Curve

This is a graph that plots voltage versus time, visually showing how the surface charge decreases from a charged state to near zero. It helps analyze the surface condition and internal conductivity of the material.

4. Impact Charging Time

This parameter measures the time required for a material to reach a target voltage under corona discharge conditions. It reflects how easily the material becomes charged.

Testing Principle

The working principle of the Static Charge Decay Tester is based on corona discharge charging followed by real-time monitoring of voltage decay.

During testing, a high-voltage power supply generates a corona discharge that emits ions onto the material surface, charging it either positively or negatively. After charging, the corona source is turned off, and a measurement probe records how the surface voltage decreases over time. By analyzing the voltage-time data, the system calculates parameters such as decay time and half-life.

Structure and Main Components

A typical Static Charge Decay Tester consists of the following key parts:

1. High-Voltage Power Supply and Corona Discharge Unit

This component generates the high-voltage corona needed to charge the material without physical contact.

2. Measurement Probe and Data Acquisition System

The probe monitors surface voltage changes during the decay process and transmits data to a processor or computer for analysis.

3. Control and Display System

This includes a screen and control interface (buttons or touchscreen) that allows users to set test parameters such as voltage level, polarity, and test duration while displaying real-time results.

4. Analysis Software

Modern instruments usually include software that automatically generates decay curves, calculates half-life, and produces complete test reports.

Relevant Standards

To ensure consistency and comparability of results, testing is often conducted in accordance with recognized standards, including:

GB/T 12703.1 – Chinese standard for measuring electrostatic decay performance of materials.

FZ/T 01042 – Textile industry standard related to electrostatic decay testing.

JIS L1094 – Japanese standard for evaluating electrostatic behavior of textiles.

Certain ISO standards also include methods related to electrostatic properties of materials.

These standards specify environmental conditions, sample preparation methods, and test parameter settings to ensure reliable and comparable results across laboratories.

Testing Procedure

A typical test process includes the following steps:

Sample Preparation

The material is cut to standard size and cleaned to remove dust or contamination.

Setting Charging Conditions

The sample is fixed on the test platform, and parameters such as corona voltage and polarity are set.

Applying Corona Charge

The corona discharge is activated to charge the sample surface to a target voltage.

Measuring Decay Process

Charging is stopped, and the system records the voltage decay over time.

Data Analysis

The software calculates key parameters such as decay time and half-life and generates a test report.

Application Fields

The Static Charge Decay Tester is widely used in various industries:

Material R&D: Evaluating antistatic properties of new materials.

Textile Industry: Testing fabrics to prevent static-related problems such as dust attraction and discomfort.

Electronics Industry: Assessing antistatic materials to protect sensitive components from electrostatic damage.

Quality Control: Ensuring consistency and stability in mass-produced materials.

Factors Affecting Test Results

Environmental conditions, especially humidity and temperature, significantly influence static charge behavior. Higher humidity generally accelerates charge dissipation.

Additionally, surface condition, material thickness, and fiber structure also affect test outcomes. Therefore, comparative tests must be conducted under consistent conditions.

Comparison with Other Static Testing Instruments

Other electrostatic testing devices exist, such as electrostatic field meters (which measure surface electric field strength) and surface resistivity testers (which measure electrical resistance).

While these instruments serve different purposes, the Static Charge Decay Tester is uniquely suited for analyzing dynamic charge dissipation behavior, providing a complete decay curve and quantitative parameters for comprehensive evaluation.

The Static Charge Decay Tester is a crucial tool for evaluating electrostatic performance of materials. By quantitatively measuring charge dissipation behavior, it provides valuable data for material development, quality control, and safety assessment.

Beyond measuring decay time and half-life, it also generates decay curves that enable deeper analysis of material electrical properties. This instrument is widely used in textiles, plastics, and electronics, helping improve antistatic performance across industries. Supported by standardized testing methods, its results are authoritative, comparable, and essential in modern manufacturing and scientific research.