The flow cell of the photoresist method is a key component of the photoresist particle counter, mainly used for detecting particles in liquids. The flow cell of photoresist method works based on the principle of photoresist method. The parallel beam passes vertically through the flow cell. When there are no particles in the liquid flow, the photodetector receives a stable light signal and outputs a constant voltage. When particles pass through the detection area of the flow cell, they will block some of the light, weakening the light signal received by the photodetector and generating a negative pulse signal. The amplitude of the pulse signal is proportional to the size of the particles, and the number and amplitude of the pulse signal can be used to measure the number and size of small particles in the measured liquid.
The flow cell of the photoresist method is the core component of the photoresist particle counter, which mainly provides a controlled optical measurement environment for particle detection in liquid samples.
Specifically, the role of the circulation pool is reflected in the following aspects:
Forming an optical detection channel: The flow cell is a channel with a very small cross-section, where the liquid to be tested flows at a stable flow rate.
A parallel laser or LED beam will pass through this flow cell, forming an accurate optical sensing area.
Implementing particle shading effect: When particles in the liquid pass through this sensing area, they block the propagation path of some light, causing an instantaneous decrease in the light intensity received by the photodetector.
This "shading" effect is the basis of photoresist detection.
Generate signals related to particle characteristics: the amplitude of light intensity attenuation (i.e. the size of the signal pulse) is proportional to the projected area of the particles (i.e. the particle size), while the number of signal pulses corresponds to the number of particles.
Therefore, the design of the optical path within the circulation pool directly determines the accuracy of the signal.
Ensuring stability and repeatability of detection: A well-designed flow cell can ensure that liquid samples pass through the detection zone at a constant flow rate and uniform distribution, which is important for obtaining stable and reliable counting and particle size analysis results.
In summary, the photoresist flow cell provides an accurate optical window, allowing the instrument to achieve high-precision detection of particle size and quantity in liquids by measuring the obstruction of light by particles.