Improved electronic gate technique, for particle counting and sizing in liquids.

Area of Science:

• Analytical Chemistry
• Materials Science
• Physical Chemistry

Background:

• Particle size distribution analysis is crucial in various scientific and industrial applications.
• Traditional methods for particle analysis in liquids face limitations in signal-to-noise ratio and accuracy.
• Accurate characterization of particles in liquid media is essential for quality control and research.

Purpose of the Study:

• To develop an advanced detector system for enhanced particle counting and size distribution measurements in liquids.
• To improve the signal-to-noise ratio for more reliable particle detection.
• To achieve linearised pulse height/particle size relationships for accurate quantification.

Main Methods:

• Utilized a four-electrode detector design to improve signal-to-noise ratio.
• Employed an instrumentation amplifier with a high-pass filter as a preamplifier.
• Incorporated cylindrical electrodes and a coaxial aperture to reduce detector capacitance.
• Developed a new baseline restorer and log-antilog amplifier circuit for signal linearisation.
• Implemented a stepping motor actuated digital sampling system for flexible and accurate volume sampling.

Main Results:

• Achieved a markedly improved signal-to-noise ratio compared to conventional methods.
• Reduced detector capacitance, leading to lower signal detection levels and enhanced pulse shape.
• Demonstrated flexible and accurate volume sampling capabilities.
• Successfully linearised the pulse height/particle size relationship for precise measurements.

Conclusions:

• The developed four-electrode detector system significantly enhances particle counting and size distribution analysis in liquids.
• The instrumentation and signal processing techniques employed lead to superior accuracy and reliability.
• This method offers a robust solution for precise particle characterization in various liquid samples.