ISO 21501-4:2008JJF 1190-2008 Standard Differentiation Inventory
Details
There are significant differences between the international standard IS021501-4:2008 and the Chinese standard JJF1190-2008 in the use and calibration process of dust particle counters. These differences not only affect the performance evaluation method of counters, but also directly affect the production quality of counters. Let's explore in depth the main differences between these two standards and why some counters, although able to pass the JJF standard, cannot meet the requirements of ISO standards.
Brief introduction ISO21501-4:2008is an international standard aimed at ensuring the accuracy and consistency of dust particle counters. It specifies in detail the calibration method of the counter, including the weighing of pulse signals. JJF 1190-2008is a domestic standard in China that focuses on whether the final result of the counter, i.e. the particle size distribution, meets the requirements, rather than the specific measurement process.
Differences 1.Measurement process vs. results
ISO 21501-4:2008 requires measurement of pulse signals to verify the accuracy of counters throughout the entire measurement process. This means not only ensuring the accuracy of the final particle size distribution data, but also verifying that the counter can maintain precision at every step of particle detection.
JJF 1190-2008: Focus more on whether the final particle size distribution results meet the standards. As long as the counter can provide results that meet the requirements, it is considered qualified.
2.Requirements for pulse signals under ISO standards
Pulse Height Analyzer (PHA): It must be able to accurately measure and record the scattered light pulse signals generated by particles passing through a beam of light, ensuring precise classification of particle size.
Counting efficiency: Use calibration particles of known size (such as polystyrene latex PSL) for testing. For the minimum detectable particle size, the counting efficiency must be 50 ± 20%; For particle sizes of 1.5 to 2 times, the counting efficiency must reach 100+10%.
Particle size resolution: PHA needs to have sufficient accuracy to distinguish small differences in particle size. The particle size resolution should be ≤ 15%.
False counting: When no particles pass through, the pulse signal recorded by PHA should be extremely low, meeting the manufacturer's 95% upper confidence limit.
Calibration method: Using standardized monodisperse particles and high-precision optical and electronic equipment, measure and analyze the pulse signals generated by each particle passing through the beam to ensure the accuracy of the measurement process.
3.Requirements for particle size distribution under JJF standard
Particle size distribution measurement: mainly focuses on whether the final particle size distribution result meets the standard. By using specific calibration particles, ensure that the counter can provide particle size distribution data that meets the standard.
Measurement steps: including visual inspection, insulation resistance testing, electrical strength testing, self purification time measurement, flow error measurement, timing error measurement, repeatability testing, particle size distribution error measurement, and particle concentration indication error measurement.
Technical indicators: specific technical indicators and requirements such as appearance, insulation resistance, electrical strength, self-cleaning time, flow error, timing error, repeatability, particle size distribution error, and particle concentration indication error.
Reasons for compliance with JJF but notIS0 1.Process control
The ISO standard requires the detection and evaluation of each pulse signal during the measurement process. This requires the counter itself to have high-precision optical and electronic components.
The JJF standard only checks whether the indicated values of each particle size meet the requirements, so that the counter manufacturer can perform coefficient correction on the indicated values to make the final data comply with the JJF standard, but its process control cannot meet the strict requirements of the ISO standard
2.Accuracy Requirements
The high precision requirement of the ISO standard means that the counter must strictly achieve the counting efficiency of the minimum particle size range.
However, the JJF standard does not require the minimum particle size range counting efficiency, only the particle size distribution error requirement needs to be met, which makes it unable to meet the IS0 standard, even if the final result meets the JJF standard.
industry impact The impact of this difference on the industry is significant. Using high-precision counters that comply with the ISO standard ensures the accuracy and reliability of measurement results in any environment. This is particularly important for industries such as pharmaceuticals and electronics manufacturing that require extremely high levels of cleanliness.
However, relying solely on devices that comply with JJF standards may not provide sufficient accuracy guarantees in certain situations, especially in application scenarios that require extremely high precision measurements. This is also why more and more international companies and high-end manufacturers tend to adopt counters that comply with the ISO standard to ensure high standard requirements for their products and environment.
Understanding these differences when choosing a dust particle counter can help businesses make more informed decisions by selecting the most suitable counter, ensuring the reliability and accuracy of their measurement results. Shanghai Lasensor offer the good quality laser air dust particle counter, gas particle counter, inline particle counter, portable particle counter.Welcome to consult us!