Download video  [45MB]

Liquid-borne particle counter LQB 1-200-L-T

" In situ continuous measurement of size distribution and concentration of particles in a wide size and concentration range in liquids having different viscosity " Measurement of the pulse hight and pulse duration of the photo-electric signal " Computer controlled and portable, menu driven operating instructions with different types of read-out and recording, variable number of size ranges, 2D and 3D differential and integral size distribution display, statistical data evaluation.

PURPOSE

The LQB 1-200-L-T liquid-borne particle counter is designed on the basis of previously developed devices LQB-1-200 to measure the size distribution and concentration of particles suspended in various liquids whose viscosity is between near 0 and 10 poise. The LQB 1-200 can be used to test the purity of parent solutions in pharmacology, hematology, biology, toxicology, health care, semiconductor process liquids, hydraulic fluids, environmental control, photochemical industry, refining industry, control of screening and cleaning efficiency, etc.

OPERATION

The particle size distribution in the LQB 1-200-L-T is determined by comparing the detected pulse heights and pulse duration of the optical signal that correspond to the single particle flow through a small illuminated zone with a standard calibration curve, obtained previously from a set of uniform particles of known diameter. The pulse height and pulse duration of the signal is evaluated and stored separately by two independent multi-channel analyzers. The liquid to be tested is pumped through a small illuminated zone by a high capacity pump with a computer-controlled motor drive. The rotation frequency of the pump can be adjusted in a wide range depending on the viscosity and volume of the liquid to be tested. The controlled flow rate of the liquid is also measured, so not only size distribution but concentration of the single particles can also be determined. The light intensity of the illumination at the beginning of the measurement is automatically fitted to the transparency of the given parent liquid and controlled during the measurement. The flow rate is also continuously controlled and stabilized at the preset value after each measuring cycle. An alarm level can be set for each size range.

DATA EVALUATION

The data evaluation system comprises optoelectronic detecting and filtering, multi-channel signal analyzing, interface and PC. The optoelectronic signal is evaluated by a 64 and a 128 channel analyzer, controlled by the computer, so the pulse duration and amplitude of the signal is separately stored. The number of size ranges and their limits can easily be changed by the software. The possibility to set and control the measurement parameters, display, evaluation and storage of the results combine to provide user friendly software.

SOFTWARE

The software package provides menu driven operation with the following main menu items: INFORMATION, SET PARAMETERS, MONITORING, MEASUREMENT, DATA PRO- CESSING, etc. Each main menu item contains sub-items, e.g. DATA PROCESSING contains LOAD DATA FROM DISK, REPLAY MEASUREMENT, CONCENTRATION TABLE, GRAPHIC TIME DIAGRAM, CALCULATE MAIN VALUE, EXPORT DATA TO FOXGRAPH or EXCEL etc. FoxGraph or Excel enables the presentation of measured data in a variety of 2 and 3 dimensional histograms and diagrams, where the axis may be, e.g. concentration, size, time (or number of cycles), so the time dependence of measured distributions can be easily displayed.

SPECIFICATIONS

Configuration LQB 1-200-L.Tcounter unit and AT/486 IBM compatible lap-top
PC with software
Overall size range 1 - 200 m
Size ranges 1; 3; 5; 10; 30; 50; 100; 200 m, variable
Counting modes cumulative and differential
Size resolution 6 bit, logarithmic
Max. particle concentration 10 000 particles/ml
Alarm level setting 1 - 10 000 particles/ml in each channel
Flow rate 20 - 80 ml/min, variable, adjusted via feedback
Measurement cycle time 1 sec - 3 600 sec, selectable in 1 sec
Number of preset cycles 1 - 100
Number of stored cycles 8 000 / M byte
Viscosity range of fluid 0.01 - 1 poise
Maximum level difference
between the LQB and liquid 1 m for water
Data display variety of tables, 2D and 3D histograms
Light intensity control automatically adjusted via feedback circuit using built-in
photo-detector
Time required for each minimum of one measuring cycle; successive cycles can be
measurement averaged for increased accuracy
Cabling 10 m length cable with connectors between PC and
LQB 1-200-L-T counter unit
Dimensions counter unit - 460 x 300 x 135 mm
Lap-top PC - 260 x 200 x 38 mm
Weight (LQB 1-200 + PC) 10 + 1.4 kg
Power requirements 65 W, 220 V, 50 Hz