The debugging of spray particle size analyzer is a systematic process, which needs to combine many factors such as hardware configuration, optical calibration, sample suitability and parameter optimization. The following will elaborate on six core aspects:
1、 Hardware system inspection and environment preparation
Equipment installation and stability verification
Ensure that the instrument is placed on a stable horizontal workbench, away from vibration sources and electromagnetic interference. The host and computer should maintain a distance of at least 1 meter to avoid signal interference.
Check if the grounding wire is reliably connected to prevent static electricity accumulation from affecting the stability of the optical system.
Optical component initialization
Select a suitable light source based on the particle size to be tested: short wavelength lasers are preferred for small particles (<1 μ m); Long wavelength lasers can be used for large particles.
Confirm whether the geometric arrangement of the detector meets the requirements of wide-angle coverage to ensure complete collection of scattered light signals.
2、 Optical path calibration and signal optimization
Benchmark calibration process
Use standard particles for instrument calibration, verify measurement accuracy through standard samples with known particle size distribution, and ensure that the indication error is less than 0.5%.
Adjust the optical platform to a horizontal position and enable the autofocus function to optimize the alignment of the laser beam and detector.
Background noise elimination
Perform a blank run test to deduct baseline drift caused by airborne particles or solvent residue. If the signal-to-noise ratio is insufficient, the testing distance can be shortened or the laser power can be increased.
3、 Sample processing and injection system debugging
Dispersion medium and concentration control
Water based samples use water as the medium, while oil-based samples use organic solvents such as ethanol/acetone, and surfactants are added to enhance the dispersion effect.
Determine the optimal concentration range through gradient experiments to avoid signal saturation or weakness caused by occlusion effects.
Pre treatment process matching
Samples containing impurities need to be filtered through a filter screen to retain effective particles while removing agglomerates.
Activate the built-in ultrasound device to further depolymerize nanoscale particles, and control the ultrasound time within 5-10 minutes to prevent overheating and structural damage.
4、 Parameter Setting and Dynamic Debugging
Basic test parameter configuration
Adjust the pressure range according to the nozzle type: low pressure produces larger droplets, high pressure refines particle size.
Set the sampling frequency and duration to ensure the capture of typical data points during the transient atomization process.
Advanced features enabled
Input the refractive index and absorption parameters of the sample into the analysis software to improve the accuracy of Mie scattering calculations.
Enable real-time monitoring mode to continuously record changes in droplet distribution within the moving area.
5、 Data validation and result correction
Multidimensional data analysis
Compare the deviation of characteristic particle size indicators such as Dv50 and Dv90 with industry standard values, generate histograms and cumulative curves to evaluate distribution patterns.
Using Sauter average diameter to quantify unit volume surface area and assist in process evaluation such as combustion efficiency.
Abnormal data processing
After removing outliers, re fit the curve and replace the nozzle or adjust the fan face opening if necessary to improve atomization uniformity.
6、 Long term maintenance and fault prevention
Regular maintenance plan
Clean the sample tank and pipelines weekly, check the wear of pump pipes monthly, and replace them in a timely manner.
Every quarter, professional personnel conduct extreme vacuum tests (should reach below 0.1Pa) and clean up accumulated pollutants in the cold trap.
Common problem response
Signal fluctuation: Check the stability of the light source or reinstall the light path components.
Poor repeatability: Check the uniformity of sample dispersion and consistency of injection flow rate.