Suzhou Yitai Environmental Technology Co., Ltd., as a manufacturer of intelligent clean environment detection instruments, is here to discuss the necessity of calibrating dust particle counters today

Why is it necessary to calibrate the dust particle counter regularly

In environments such as clean rooms, sterile production lines, hospital operating rooms, laboratories, etc. that have strict requirements for air cleanliness, dust particle counters are the "eyes". It monitors the quantity and size of suspended particles in the air in real time, and is a key equipment for ensuring product quality, scientific research accuracy, and medical safety. However, many users have a misconception that once purchased, this precision electronic instrument can provide accurate data once and for all. In fact,Regular calibration is the lifeline to ensure the accuracy and reliability of dust particle counter data.

This article will delve into the fundamental reasons why dust particle counters must be calibrated regularly.

1、 What is calibration? ——Not just 'zero adjustment'

Firstly, we need to clarify the concept of 'calibration'. Calibration is not a simple cleaning or zeroing operation, but a rigorous process of comparing, verifying, and adjusting the measurement results of a counter with higher-level national or international standards. By using standard substances (such as standard particles with known particle size and concentration), professional technicians will verify and adjust the following core parameters of the counter:

1. Accuracy of particle sizeEnsure the accuracy of the instrument's discrimination threshold for specific particle sizes (such as 0.3 μ m, 0.5 μ m, 5.0 μ m).

2. Counting efficiencyTo verify the actual counting ability of the instrument for standard particles passing through the optical sensing area, it is usually required to have a reasonable counting efficiency range at a specific particle size.

3. sampling flowEnsure accurate and stable sampling volume of the instrument per unit time (such as 28.3L/min, 50L/min, 100L/min).

4. Self purification time and coincidence errorEvaluate the instrument's ability to distinguish multiple particles passing through the detection area simultaneously in a high concentration environment.

2、 Why do we need regular calibration? ——The inevitability and risk of precision drift

The working principle of a dust particle counter is the light scattering method. Any factor that affects its optical system, pneumatic system, and signal processing system may cause its performance to gradually 'drift' over time. Regular calibration is precisely to cope with this inevitable accuracy degradation, and the main reasons are as follows:

1. Performance degradation and pollution of core optical systems

• Laser agingAs the core light source, the output power and stability of the laser will slowly decrease with increasing usage time. The change in light intensity directly affects the intensity of scattered light from particles, leading to inaccurate particle size criteria - which may mistake large particles for small particles or fail to detect small particles that should have been detected.

• Optical lens contaminationDespite the protection of efficient filters, extremely fine oily aerosols or long-term accumulation of trace dust in the environment may still contaminate optical lenses (such as lenses and windows). This will reduce the transmittance of the optical path, scatter background light, increase instrument background noise, thereby affecting detection sensitivity and accuracy.

2. Changes in key pneumatic systems

• Sampling flow fluctuationThe vacuum pump responsible for extracting air will wear out with use, and the flow sensor itself may also drift. Inaccurate sampling flow can directly lead to errors in particle concentration calculation. For example, if the actual flow rate is lower than the set value, it will cause the calculated particle concentration to be lower than the true concentration, resulting in a fatal risk of "false compliance".

3. Aging and drift of electronic components

• The sensitivity of detectors such as photomultiplier tubes (PMT) or photodiodes may vary, and the reference voltage for signal amplification circuits and discrimination thresholds may also drift. The small changes in these electronic systems, when accumulated, can have a significant impact on particle size resolution and counting accuracy.

4. Meet the mandatory requirements of regulations and quality systems

• Almost all national and international standards related to clean environments, such as ISO 14644-1, GMP (Good Manufacturing Practice), EU Appendix 1, etcmandatoryDust particle counters used for verification and monitoring must be calibrated regularly and provide traceable calibration certificates.

• Lack of valid calibration certificates for testing data is invalid during audits, customer factory inspections, or qualification certifications, which may result in serious non conformities and even affect production permits.

5. Ensure data reliability, avoid quality and financial risks

• Risk of 'false negative'If the counter reads low due to lack of calibration, it will not accurately reflect the pollution level of the clean environment. In drug production, this may lead to unqualified products being misjudged as qualified and entering the market, causing huge drug safety incidents and recall losses.

• Risk of false positivesIf the reading is too high, it may lead to excessive alarms for qualified environments, causing unnecessary shutdowns, investigations, and cleaning, resulting in decreased production efficiency and resource waste.

• Wrong decisions based on incorrect dataInaccurate data can mislead maintenance teams and prevent them from correctly evaluating the integrity of high-efficiency particulate air (HEPA) filters, room pressure differentials, and the effectiveness of personnel operating procedures, thereby preventing them from taking appropriate corrective measures.

3、 How long is the calibration cycle?

The recommended calibration period for dust particle counters is usually12 monthsThis is a general practice based on the balance between instrument performance stability and risk management. However, in the following situations, it may be necessary to shorten the calibration cycle:

• The instrument is used frequently.

• The working environment is harsh (such as high concentration, high humidity, and corrosive gases).

• After experiencing severe vibrations, impacts, or repairs.

• During the verification process, abnormal data was found.

Conclusion

The dust particle counter is not a device that can be set up and forgotten. It is a precision measuring instrument, and its accuracy directly affects the quality and safety of the final product or service.Regular calibration is not an optional cost, but a necessary investment.It invests in the credibility of data, the stability of product quality, and more importantly, the compliance and reputation of the enterprise. Only through strict and periodic calibration can we be confident that these "eyes" that monitor clean environments are always bright and reliable, safeguarding our core business.

Yitai Jingke dust particle counter, etiedt intelligent laser dust particle counter, remote dust particle monitoring system ET-CRMS

True 0.1 micron particle counter Suzhou Yitai is more professional