Laser particle counter

Particulate quantitative air sampling will be performed using device CI-500 innovation laser particle counter (serial no. mentioned on the monitoring format) according to SOP (provide number)... 

Chawla, R, and J.M. deMan. 1990. Measurement of the size distribution of fat crystals using a laser particle counter. J. Am. Oil Chem. Soc. 67 329-332. 

Spectrex PC 2000 Laser particle counter counts and sizes particles, from 0.5 to 100 pm in diameter, in both flowing and in-situ liquids. The PC 2000 uses near-forward scattering from a revolving laser beam (900 rpm.) for particle sizing and counting of in-situ and flowing liquids [115]. A He-Ne laser beam is focused to a small, well-defined volume (10 ml) within the liquid. Total particle count within the range 0.5 to 100 pm can be determined in less than a minute. Readout is in 1 pm steps from 0.5 to 17 pm and in five channel steps from 17 to 100 pm. Distribution may be presented on a number or a volume basis. A small vial attachment permits... 

Total particle levels should meet the required specifications and be measured, with the machine at rest, at defined intervals by means of a laser particle counter (or other suitable instrument) to demonstrate continued compliance. 

Lipid particulate analysis can be achieved with most commercial laser particle counters. Compendial requirements for suspensions also allow for sizing via electron microscopy determinations, which can provide... 

Particulates are critical in sterile filtration, specifically of injectables. The USP 24 United States Pharmacopoeia) and BP British Pharmacopoeia) quote specific limits of particulate level contaminations for defined particle sizes. These limits have to be kept and, therefore, the particulate release of sterilizing grade filters has to meet these requirements. Filters are routinely tested by evaluating the filtrate with laser particle counters. Such tests are also performed with the actual product under process conditions to proove that the product, but especially process conditions, do not result in an increased level of particulates within the filtrate. 

Figure 15. Contom plot of monthly average particle number distributions measured in Atlanta, Georgia. SMPS = scanning mobility particle sizer, used to measure numbers of particles with Dp = 20-250 mn. A laser particle counter is employed to measure particles with diameters of 0.1-2 pm. Nanoparticles with Dp = 3-50 mn are measured with a nano-DMA in conjunction with a UCPC. The white boxes without data indicate times of eqipment failure. From Woo et al. (2001). Used by permission of Taylor Francis, Inc.

Laser particle counter Number Portable and easy to operate mainly... 

Owing to its portability, versatility and lower detection size limit, laser particle counters have been traditionally used to measure particles down in the low microscale range. However, particles that are less than 300nm will not be detected by this method [17]. This limits the applicability in some nanotechnology industries, where particles are quite frequently found an order of magnitude smaller. The more sensitive optical samplers that currently exist are not easily portable, thereby greatly reducing their industrial applications for workplace exposure assessments. 

Pilot set-up involving both CPC and laser particle counter. 

Sampling Detectors. These consist of tubing distributed from the detector unit into the area(s) to be protected. An air pump draws air from the protected area back to the detector. A high-intensity strobe, laser particle counter, or cloud-chamber smoke detector may be used... 

Peters, C., Gebhart, J., Roth, C., Sehrt, S., Test of High Sensitive Laser Particle Counters with PSL-Aerosols and a CNC Reference, J. Aerosol Soi., 1991, 22, 5363-5366. 

One of SACHEM s products is tetramethylammonium hydroxide (TMAH), which is sold to semiconductor industries. Suspended particles in TMAH solutions could cause severe mechanical damage to the electronic devices manufactured by their customers. The determination of the particle content in such solutions is therefore critical. It is performed with a laser-equipped particle counter, which provides 70% detection efficiency. The counting must take place in a clean room because tiny airborne particles can land in the solutions and give them a false high reading. A class 1000 environment is required in this case, which means that the count of particles in the air that are greater than or equal to 0.5 jrm in diameter must be less than 1000 per cubic foot. Typically, a customer s specification for TMAH solutions is less than 100 particles per milliliter for particles greater than or equal to 0.5 fim in diameter. 

Paul Plumb of SACHEM Inc. counts particles in the ultrapure solutions of TMAH by a laser-equipped particle counter in the clean room. Notice the hair net and special lab coat. 

Figure 13.10 Response calculations for a particle counter that collects He-Ne laser light scattered between 4 and 22°. Reprinted with permission from R. G. Pinnick and J. J. Auvermann, J. Aerosol Sri., 10 (1979), 55-74 copyright 1979, Pergamon Press, Ltd.

Note DMS differential mobility spectrometer, SMPS scanning mobility particle sizer, CPC condensation particle counter, TDMPS twin differential mobility particle sizer, DMPS differential mobility particle sizer, OPC optical particle counter, APS aerodynamic particle sizer, MAS mass aerosol spectrometer, LAS-X optical laser aerosol spectrometer, ELPI electrical low pressure impactor... 

Knollenberg and Veal [80] discuss operation, design and performance of optical counters in general and a review of extinction optical particle counters has been presented by Sommer [81] cit. 82). A comprehensive review of laser-based techniques for particle size measurement, covering both stream scanning and field scanning methods, contains 167 references [83]. 

Hiac PC4000 portable liquid particle counter is a contamination measurement tool, designed to run on-line analyses of hydraulic systems and fluids. The fully self-contained counter operates in the light-blocking mode using a laser diode and reports contamination levels at 4, 6, 10, 14, 21,38 and 70 pm at a flow rate of 60 ml min. ... 

Hiac 2000 liquid particle counter provides an inexpensive means to transfer up to four channels of particle size information data from sensor to host computer system. Data can be viewed in real-time via a liquid erystal display. The 2000 interfaces to all Hiac liquid sensors including the MicroCount, submicron and HRLD laser sensors. Applications include point-of-use monitoring for corrosive chemieal delivery systems, DI water lines, wet process tools, hydraulic oil systems and parts cleaning... 

Pacific Scientific Met One 210 Liquid Particle Counter is used to measure particles in clean fluids used in electronic, pharmaceutical and other manufacturing processes. It classifies particles in six size ranges in the 0.4 to 25 pm size range using laser diode based forward light scattering. Maximum count rate is 8000 particles per minute at a fluid flow rate of 100 ml min. ... 

Rion Laser Based Liquid-borne Particle Counter uses an optional sampler and sideways scatter to allow off-line, on-line and automatic measurement down to 0.2 pm using a range of configurations. A range of sensors is available for use with either corrosive or aqueous liquids. 

Fig. 9.14 The Spectrex SPC-510, (a) schematic of particle counter, (b) laser beam optics. 1 on-off switch, 2 digital readout, 3 count button, 4 threshold setting dial, 5 Illuminate button, 6 prism, 7 secondary lens, 8 target, 9 bottle, 10 sensitive zone, 11 scanning laser beam, 12 prism, 13 beam splitter and beam strength monitor, 14 scanner, 15 mirror, 16 lamp.

The limit of detection of an optical particle counter depends on instrument noise, Rayleigh scattering by the air molecules, and stray light resulting from imperfect optics. For commercial counters with an incandescent light source, the limit of resolution is about 0.3 /tm. Instruments with laser light sources can go down to about 70 nm. 

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