ParticleTrack is a probe-based instrument that uses a measurement technique called Focused Beam Reflectance Measurement (FBRM).
The probe is inserted directly into process streams, at an angle, to ensure particles can flow easily across the probe window where the measurement takes place. A laser beam is launched down the probe tube through a set of optics and focused to a tight beam spot at the sapphire window. The optics rotate at a fixed speed (typically 2m/s) resulting in the beam spot rapidly scanning across particles as they flow past the window.
As the focused beam scans across the particle system, individual particles or particle structures will backscatter the laser light to the detector. These distinct pulses of backscattered light are detected, counted, and the duration of each pulse is multiplied by the scan speed to calculate the distance across each particle.
This distance is defined as the chord length, a fundamental measurement of the particle related to the particle size. Typically, thousands of particles are counted and measured per second, allowing a precise and highly sensitive chord length distribution to be reported in real time.
The chord length distribution tracks how particle size and count change from the beginning, until the end of a process. Statistics from each chord length distribution, such as counts in fine and coarse size classes, can be trended over time.
By changing operating conditions and tracking particles and particle structures as they naturally exist in process, scientists are better able to understand, optimize and control their particle systems.