The operating specifications of the cleanliness tester

The operating specifications of the cleanliness tester need to be adjusted according to the specific instrument type and application scenario, but the following general procedures can ensure the accuracy and reliability of the test results:

1. Preparation before operation

Environmental control

Operate in a clean room or dust-free environment （e.g. ISO Class 5-8） to avoid external contamination.

Control temperature and humidity （usually 20±5℃， humidity ≤65%RH）。

Instrument calibration

Daily calibration according to instructions （e.g. optical instruments need to adjust light source intensity, particle counters need to verify standard particles）。

Periodic external calibration （annually or as per standard recommendation cycle, such as ISO 16232 requirements）。

Sample preparation

Surface cleaning: Clean sampling tools （e.g. wipes, filters） with isopropyl alcohol or deionized water to avoid cross-contamination.

Tool selection: Select the sampling method according to the pollutant type （such as sticky roller particle collection, swab organic matter collection）。

2. standardized operation process

Sampling procedure

Contact sampling:

Wipe method: Use a solvent-soaked swab to wipe a fixed area （such as 5cm×5cm） in one direction to avoid repeated paths.

Flushing method: flush the measured surface with a quantitative solvent and collect the flushing solution.

Non-contact sampling:

Laser scanning: Set the scanning area and resolution to ensure coverage of the target area.

Vacuum adsorption: Control suction to avoid surface damage.

Detection execution

Optical inspection:

Adjust the wavelength of the light source （such as ultraviolet light to detect grease, white light to detect particles）。

Record the scattered light intensity or fluorescence signal.

Chemical analysis:

Extraction liquid injection testing equipment （such as HPLC, IC）， set the standard curve.

Particle count:

Select the particle size channel （such as ≥5μm, ≥15μm） and count the number of particles per unit area.

Data recording

Label the sample information （material, source, test time）。

Save the original graph or value （e.g. histogram of particle distribution）。

3. Key points to note

Pollution control

Operators should wear dust-free gloves and masks to avoid contamination of samples with sweat or skin oils.

Use tweezers or vacuum pens to handle the sample to minimize hand contact.

Exception handling

If the test value exceeds the standard, repeat sampling （at least 3 times） to verify the result.

Check light source life, sensor cleanliness or calibration status when the instrument alarms.

Standard compliance

Reference industry specifications （e.g. ISO 16232, VDA 19, NASA-STD-6001） to set limits.

Medical equipment shall comply with GB/T 14233.1 （microbial contamination） or ISO 15883 （cleaning effect）。

4.Maintenance and calibration

Daily cleaning

Optical Windows are wiped with compressed air or lens paper.

After ultrasonic cleaning, the sampling tool is dried and stored.

Scheduled maintenance

Replace light sources （such as UV lamps every 2000 hours）。

Lubricate mechanical parts （e.g. particle counter drives）。

Record management

Establish calibration records, maintenance logs and inspection data files.

Traceability requirements: Save the original data for ≥5 years （some industries such as medicine need ≥10 years）。

5. Report generation

Result determination

Compare standard limits （e.g. ISO 4406 cleanliness level: 18/15/12 for different particle concentrations）。

Label the detection method （such as "ultraviolet fluorescence detection of oil residue"）。

Conclusion and suggestion

Qualified: Record "Meet standard XX".

Failed: Indicate the type of pollutants that exceed the standard and possible sources of pollution （for example, metal particles >100μm are detected, it is recommended to check the wear of processing tools）。

Example: Cleanliness test flow for electronic components

In the Class 100 clean table, wipe the PCB surface with a polyester swab soaked with isopropyl alcohol.

The swab was subjected to ultrasonic shock in the extract for 20 minutes.

The concentration of chloride ions was detected by ion chromatograph （limit ≤1.0μg/cm²）。

Record data and generate a report marked "IPC-A-610 compliant".

By strictly following the operating specifications, human error can be minimized to ensure the scientific and legal validity of cleanliness test results.

2025-03-20 10:30