Principle of operation

The QT-1 laser particle size analyzer uses Mie scattering theory to measure particle size, considering the refractive index of the particles and dispersion medium. According to Mie’s theory, a particle will scatter light at an angle determined by that particle’s size. A collection of particles will produce a pattern of scattered light defined by intensity and angle that can be transformed into a particle size distribution result. The data of particle test can be calculated in two ways: unconstrained fitting inversion and constrained fitting inversion. The constrained fitting inversion is a relatively simple way. The particle size distribution is inverted with the assumption that there is a certain distribution pattern in particles. However, the deviation exists between the assumption and the reality. Therefore, the tested results through the constrained fitting inversion cannot truly reflect the real size distribution of the particles. In unconstrained fitting inversion, no distribution pattern of particles is assumed before the test, and the size distribution of the particles is directly and precisely calculated from the light intensity. In this way, the instrument requires reasonable sensor design and size grading to ensure its high performance. The particle size distribution can be precisely calculated with QT-1 Laser particle size analyzer which uses the optimized non-uniform cross 3D fan-shaped sensor array and the reasonable size grading.

Specifications

• Measurement range：0.05 ~ 800 µm
• Accuracy：<±1% (Chinese National Standard D50)
• Repeatability error：<±1 % (Chinese National Standard D50)
• Power supply：220±10V AC, 50Hz, 200W
• Dimensions：1000 x 330 x 320 mm
• Weight：38 KG

Technical features

Stable performance: The stability of the tested data is ensured by the stable optical signals from the system. The QT-1 Laser particle size analyzer uses He-Ne gas laser light source with 0.6328 micron wavelength. It can offer stable laser source signals, and serves more than 15000 hours.

Reliable data: The reliability of the tested data requires stable light signals from the system. The real results require high dispersion effect of the tested samples as well as even distribution of the tested dispersed liquid.

Sensors: Unique design of the photoelectric sensor, high sensitivity, with 1 master sensor and several auxiliary sensors, non-uniform cross 3D  fan-shaped  sensor array, 105 degree of the maximum testing angle, overall test of the signals.
Light path: With the design of 1 measuring range, unique gathering light path , less Fourier lens, wide measuring range, high resolution, free adjustment of light path.

Sample dispersion: The ultrasound system of QT-1 Laser Particle Analyzer can thoroughly disperses the test samples. Super power ultrasound system (100 W) is integrated with the host machine. The ultrasound time is automatically controlled. The touch buttons are continuously adjustable. The time setting is displayed. The ultrasound time of 0 - 9min 50 seconds is adjustable. The ultrasound time is adjusted according to the sample dispersion. The ultrasound dispersion and sample testing may be done at the same time due to the good shielding. Even super aggregated particles can be dispersed sufficiently and real particle size distribution can be obtained.

Sample dispersion pool (400 ml) is integrated with the host machine, made of stainless steel, with unique design, rounded, circulating discharge, easy to clean.

QT-1 uses wet dispersion, distilled water, purified water and ethyl alcohol can be used as dispersing medium.

Homogenized dispersion: The homogeneity of dispersion can provide a stable optical signal. QT-1 uses continuous and adjustable stirring and circulation to ensure the homogeneity of dispersion.

Mixing system: choose the appropriate mixing speed according to the characteristics of the sample, to prevent particle sedimentation to dispersion mixing, stirring speed is in automatic operation and touch-button is continuously adjustable at the stirring speed from 0 to 3000 r/minutes, speed setting is displayed, open the ultrasonic system during testing process can avoid measurement errors caused by bubbles emerging from fast stirring.

Circulatory system: According to the characteristics of the sample, choose appropriate in circulation pump speed to prevent particle precipitation in the circulation line. Circulation pump speed is in automatic operation, touch-button is continuously adjustable at the circulation pump speed from 0 to 5000 r/min, pump speed setting is displayed, open the ultrasonic system during testing process can avoid measurement errors caused by bubbles emerging from fast stirring and can prevent particles from becoming aggregates.

Powerful analysis software: PADMAS (Particle Diameter Measure & Analysis System) is a powerful software that can process statistical analysis, comparison and mode conversion. It has various formats, such as differential distribution, cumulative distribution, standard classification, R-R distribution, user-defined classification, mesh-based classification and quantitative distribution. The default in the range of 0.02 -2000 micron is 130 classes. Within the measurement range, 1-130 classes can be defined by users. In the test report, there are particle size distribution chart, particle size data, and some characteristic parameters such as D10, D50, D90, the average size and specific surface. Four parameters need to be defined by users. Weight specific area and volume specific area can be mutually converted. Particle size data can be exported to Excel. It supports test report printing in Chinese or English. The page header and footer may be modified. The printing page may be previewed. Particle distribution diagrams and size data charts may be saved in picture or PDF format, which can be further used in Word. More functions may be added according to users’ requirement.

User-friendly operation: The operation is standard, quantified and simple, and it takes a short time to master the operation. The data can be tested within 1 minute.

High viewability: The test software is user-friendly. The test processes are readable and instantly refreshable. The operators can observe the instrument’s situation and the fluctuation of the test data at any time and analyze the validity and reliability of the test data. On the intelligent touch panel, there are operating keys for circulation, ultrasonic, stirring and discharge.  Standard, quantified and simple operation makes the testing time shorter and lower requirement for the operator.

Origin: China