Clarity Evaluation of Distilled Alcoholic Products with a Particle Counter

1976 ◽  
Vol 59 (3) ◽  
pp. 671-674
Author(s):  
Duane H Strunk ◽  
Bertha M Timmel ◽  
Arthur A Andreasen
Keyword(s):  
Particle Counter ◽  
Average Data ◽  
Apparent Relationship ◽  
Particle Counts ◽  
Number Of Particles

Abstract An HIAC particle counter is used to measure clarity of distilled alcoholic products. The number of particles is measured in 5 size ranges from 2 to 90 μm. Average data are given for whiskies, brandy, rum, white gin, and vodka. The highest counts are obtained for aged products and most of the particles are 2–5 μm. The particle counts of different brands of blended whiskies varied from 62 to 5265 particles/ml in the 2–90 μm range. There is no apparent relationship between nephelometer values and particle counts.

Minimum Sampling Time/Volume for Liquid-Borne Particle Counters and Monitors

1997 ◽  
Vol 40 (6) ◽  
pp. 29-34
Author(s):  
Mindi Xu ◽  
Hwa-Chi Wang
Keyword(s):  
Standard Deviation ◽  
Particle Concentration ◽  
Sample Volume ◽  
Average Concentration ◽  
Sampling Time ◽  
Operating Conditions ◽  
Average Particle ◽  
Particle Counter ◽  
Particle Counts ◽  
The Difference

A particle counter is an instrument that measures particles in all the fluid passing through its sensor, and a particle monitor measures particles only in a portion of the fluid. For liquid with an ultralow particle concentration, particles may not disperse uniformly in the liquid. Therefore, the concentrations may vary significantly from measurement to measurement if the sample volume is not large enough. To achieve the same precision, a minimum sampling time or minimum sample volume for a particle instrument needs to be specified. A Poisson distribution was used to describe the distribution of particle counts. Testing included a series of particle concentration measurements. Minimum sampling time or sample volume at a given average concentration with different error levels was determined for selected commercial particle instruments. At the same flow rate, a particle monitor always requires a longer sampling time than a particle counter to achieve a specific precision for a given concentration. The minimum sampling time also varies among instruments because of the difference in sample volume in which the particles are counted. Experiments with a particle monitor have been conducted to thest the changes in average particle concentration and the standard deviation at different operating conditions.

scholarly journals Laboratory Study of Physical Barrier Efficiency for Worker Protection against SARS-CoV-2 while Standing or Sitting

2021 ◽  
Author(s):  
Jacob Bartels ◽  
Cheryl Fairfield Estill ◽  
I-Chen Chen ◽  
Dylan Neu
Keyword(s):  
Laboratory Study ◽  
Grocery Stores ◽  
Physical Barrier ◽  
Particle Count ◽  
Engineering Control ◽  
Transparent Barrier ◽  
Particle Counts ◽  
Barrier Efficiency ◽  
Number Of Particles ◽  
Nail Salons

Transparent barriers were installed as a response to the SARS-COV-2 pandemic in many customer-facing industries. Transparent barriers are an engineering control that are utilized to intercept air traveling between customers to workers. Information on the effectiveness of these barriers against aerosols is limited. In this study, a cough simulator was used to represent a cough from a customer. Two optical particle counters were used (one on each side of the barrier, labeled reference and worker) to determine the number of particles that migrated around a transparent barrier. Nine barrier sizes and a no barrier configuration were tested with six replicates each. Tests of these 10 configurations were conducted for both sitting and standing scenarios to represent configurations common to nail salons and grocery stores, respectively. Barrier efficiency was calculated using a ratio of the particle count results (reference/worker). Barriers had better efficiency when they were 9 to 39 cm (3.5 to 15.5 inches) above cough height and at least 91 cm (36 inches) wide, 92% and 93% respectively. Barriers that were 91 cm (36 inches) above table height for both scenarios blocked 71% or more of the particles between 0.35–0.725 µm and 68% for particles between 1 to 3 µm. A barrier that blocked an initial cough was effective at reducing particle counts. While the width of barriers was not as significant as height in determining barrier efficiency it was important that a barrier be placed where interactions between customers and workers are most frequent.

On the Particles in Fogs and Clouds

1893 ◽  
Vol 19 ◽  
pp. 260-263
Author(s):  
John Aitken
Keyword(s):  
Vapour Pressure ◽  
Dust Particles ◽  
Strong Wind ◽  
Great Care ◽  
Rapid Cooling ◽  
Particle Counter ◽  
Large Curvature ◽  
Small Water ◽  
Made In ◽  
Number Of Particles

At the beginning of the paper some observations made on the water particles in clouds on the Rigi on the 21st of May last are described. Previous observations with the fog-particle counter had shown that there is a relation between the density of a cloud and the number of water particles observed. On the occasion above referred to the number was very much greater than corresponded with the density. It is pointed out that the number of dust particles in the air which become centres of condensation depends on the rate at which the condensation is taking place, quick condensation causing a large number of particles to become active, slow condensation causing a small number; and that after the condensation has ceased a process of differentiation takes place, the larger particles, robbing the smaller ones of their water, owing to the vapour-pressure at the surface of drops of large curvature being less than at the surface of drops of smaller curvature. The particles in a cloud are by this process reduced in number, those remaining becoming larger and falling quicker, the cloud thus tending to become thinner by the reduction of the number of particles and by the falling of some of them. It is shown that the exceptional readings above referred to, obtained on the Rigi, were owing to the observations then made being taken in a new and rapidly-formed cloud, due to the strong wind blowing at the time causing a quick ascent and rapid cooling and condensation, the result being the formation of a large number of very small water particles. Though the number was very great, the particles were so small they were only just visible with great care with the magnifying power used in the instrument. Previous observations on cloud particles had been made in slowly-formed or in old clouds after the process of differentiation had been in play for some time, and after the drops had been reduced in number and increased in size.

Optimization of online particle counting with a 3D-printed bubble trap

2020 ◽  
Vol 6 (3) ◽  
pp. 418-421
Author(s):  
Anja Kurzhals ◽  
Christoph Brandt-Wunderlich ◽  
Finja Borowski ◽  
Klaus-Peter Schmitz ◽  
Niels Grabow ◽  
...  
Keyword(s):  
Air Bubbles ◽  
Cardiovascular Devices ◽  
Particle Counter ◽  
Light Obscuration ◽  
Particle Counting ◽  
Custom Made ◽  
Bubble Trap ◽  
3D Printed ◽  
Particle Counts ◽  
Flow Circuit

AbstractParticulate evaluation is needed for the approval of cardiovascular devices. Air bubbles lead to higher particle counts when light obscuration method (LOM) is used. The aim of the study was to test a custom made bubble trap that removes air bubbles (2 - 100 μm) from a flow circuit prior to online particle counting. Artificially generated air bubbles were counted with an online particle counter with and without the bubble trap. Air bubbles were reduced by about 71 % to 91 % by using the bubble trap.

Measuring Particles and Bubbles in Process Chemicals at Controlled Temperatures

1999 ◽  
Vol 42 (5) ◽  
pp. 30-35
Author(s):  
Mindi Xu ◽  
Wei-Ching Li
Keyword(s):  
Manufacturing Process ◽  
Semiconductor Manufacturing ◽  
Sample Temperature ◽  
Particle Counter ◽  
Optical Particle Counter ◽  
Particle Counts ◽  
Effective Temperatures ◽  
Temperature And Pressure ◽  
A New Technique ◽  
Theoretical Simulations

Microbubbles in semiconductor manufacturing process chemicals can be produced by mechanical disturbance to the chemicals or by changing the temperature and pressure. Bubbles suspended in liquid are easily miscounted as particles when an optical particle counter is used for measuring particles. A new technique, controlling sample temperature, has been developed. Samples for measuring particles are refrigerated to a temperature that eliminates bubbles and then introduced into a particle counter for measurement. The results from these experiments indicate that sample temperature strongly affects the particle counts due to the bubbles in the liquids. Effective temperatures for bubble suppression in several process chemicals have been selected based on the experiments. To better understand bubble suppression by controlling temperature, theoretical simulations for the microbubbles in the chemicals were conducted at various temperature conditions. The results from the experiments and the theoretical simulations are compared.

scholarly journals Experimental efficacy of the face shield and the mask against emitted and potentially received particles

2020 ◽  
Author(s):  
Michaël Rochoy ◽  
Thibaut Fabacher ◽  
Isabelle Cosperec ◽  
Jean-Michel Wendling
Keyword(s):  
Short Distance ◽  
Community Setting ◽  
Particle Sizes ◽  
Small Particle Size ◽  
Comparative Performance ◽  
Particle Counter ◽  
Aerosol Generator ◽  
Optical Particle Counter ◽  
The Face ◽  
Number Of Particles

AbstractThe aim of this study was to evaluate the comparative performance of masks and face shields in different experimental configurations. An experimental setup with two mannequin heads positioned at 1.70m high and at 25 cm each other was used. A fogger generated a particle’s airflow with a speed of 5m/sec from the emitter to the receiver head mannequin. Our aerosol generator produced 3 000 times more particles than a physiological cough situation. A particle counter allowed us to evaluate the number of particles received on a mannequin head located at a very short distance of 25 cm. The amount of all particles up to the selected particle sizes were counted with an optical particle counter on channels 0.3 µm, 0.5 µm, 1 µm, 2.5 µm, 5 µm and 10 µm. The reduction factors with a protection worn by the receiver alone, by the emitter alone and then the double protection of emitter and receiver were calculated. When the receiver alone wore a face shield, the amount of total particles was reduced (54.8%), while the reduction was less when the receiver alone wore a mask (21.8%) (p = 0.003). Wearing a protection by the emitter alone reduced much more the level of particles received by 96.8% for both mask and face shield. The double protection allowed for even better results, but close to the protection of the emitter alone: 98% reduction for the face shields and 97.3% for the masks (p=0.022). Even with small particle size emission (≤0.3µm), results were of the same order. Considering our results, protection of the emitter alone or double protection is much more effective than protection of the receiver only. Validated face shield should be included as part of strategies to safely and significantly reduce transmission in the community setting, in addition to masks or for people with disabilities or medical intolerance to masks.

scholarly journals Prediction of Particulate Contamination on an Aperture Window

1996 ◽  
Vol 39 (2) ◽  
pp. 42-48
Author(s):  
Aleck Lee ◽  
Michael Fong
Keyword(s):  
Light Scattering ◽  
Incident Light ◽  
Image Analyzer ◽  
Particulate Contamination ◽  
Flight Operations ◽  
Surface Particle ◽  
Particle Counts ◽  
Contaminant Distribution ◽  
Number Of Particles ◽  
Particulate Surface

This paper presents an analysis of light scattering by surface particles on the sensor window of a missile during ascent flight. The particulate contaminant distribution on the window is calculated by tallying the number of particles in a set of size ranges. The particulate contamination at the end of the mission is predicted by adding the contributions from the events of ground and flight operations. The surface particle redistribution caused by vibroacoustic-induced surface acceleration was found to contribute the most to particulate surface contamination. The analytical surface obscuration calculation with a set of particle counts was compared with the results of the image analyzer measurement. The analytical results, which were calculated with a given function of particle shape depending on size, were more conservative than the measurement. A scattering calculation using a verified BSDF model showed that the scattering was less than 0.001 at 20 deg off the direction of the incident light in the mid IR wavelength when the surfaces were at Level 300 initially.

A Survey of Four Fluid Milk Processing Plants for Airborne Contamination Using Various Sampling Methods

1992 ◽  
Vol 55 (1) ◽  
pp. 38-42 ◽  
Author(s):  
TYH-JENQ REN ◽  
JOSEPH F. FRANK
Keyword(s):  
Sampling Methods ◽  
Raw Milk ◽  
Particle Counter ◽  
Milk Processing ◽  
Airborne Contamination ◽  
Processing Plants ◽  
Particle Counts ◽  
Milk Storage ◽  
Andersen Sampler ◽  
Fluid Milk

Air in four commercial fluid milk plants was sampled for microbiological and nonmicrobiological particles over a 4-month period. An Andersen two-stage and Ross-Microban sieve samplers, a Biotest RCS sampler, and a Met-one laser particle counter were used to sample air. Air was sampled two to three times per day in raw milk storage, processing, and filling areas. Viable particle counts per 100 L air obtained with the Andersen sampler were 2.03 ± 0.41 (log10 Mean ± SD), 2.26 ± 0.57, and 2.41 ± 0.70 in raw milk storage, processing, and filling areas, respectively. These levels were significantly (p<0.05) greater than those obtained using the RCS and Ross-Microban samplers. Overall correlations of the Ross-Microban and RCS samplers with the Andersen sampler were r2 = 0.71 and 0.62, respectively. Correlations between Andersen sampler results and number of total particles greater than 0.5 μm were r2 = 0.36 in raw milk storage, 0.15 in the processing area, and 0.18 in the filling area.

TYPES AND POPULATIONS OF MICROORGANISMS IN THE AIR OF FLUID MILK PLANTS

1970 ◽  
Vol 33 (1) ◽  
pp. 19-21 ◽  
Author(s):  
R. Y. Cannon
Keyword(s):  
Microbial Populations ◽  
Gram Negative ◽  
Milk Processing ◽  
Apparent Relationship ◽  
Keeping Quality ◽  
Particle Counts ◽  
Fluid Milk

Airborne viable particle counts in the milk processing areas of 10 dairy plants averaged 14 molds and 32 non-molds/10 liters. The bacteria isolated were primarily micrococci, Gram-negative rods (excluding coliform), bacilli, and coryne-bacteria. Twenty-five per cent of the isolates grew at 10 C in 5 days. These were principally bacilli and Gram-negative rods (excluding coliform). There was no apparent relationship between airborne microbial populations and keeping quality of the packaged milk.

Measurement of Airborne Contamination in Two Commercial Ice Cream Plants

1992 ◽  
Vol 55 (1) ◽  
pp. 43-47 ◽  
Author(s):  
TYH-JENQ REN ◽  
JOSEPH F. FRANK
Keyword(s):  
Sampling Methods ◽  
Ice Cream ◽  
Two Stage ◽  
Particle Counter ◽  
Airborne Contamination ◽  
Particle Counts ◽  
Andersen Sampler

Air in two commercial ice cream plants was sampled for microbiological and nonmicrobiological particles over a 4-month period. Sampling methods utilized Andersen two-stage and Ross-Microban sieve samplers, a Biotest RCS sampler, and a Met-one laser particle counter. Air was sampled two to three times per day in pasteurized mix storage, processing, and filling areas. Viable particle counts per 100 L air obtained with the Andersen sampler were 2.26 ± 0.47 (log10 Mean ± S.D.), 2.05 ± 0.68 and 2.31 ± 0.46 in pasteurized mix storage, processing and filling areas, respectively. These levels were similar to those obtained using the RCS sampler, but they were significantly (p<0.05) greater than those obtained using the Ross-Microban sampler. Overall correlations of the RCS and Ross-Microban samplers with the Andersen sampler were r2 = 0.69 and 0.56, respectively. Correlations between Andersen sampler results and the concentration of total particles greater than 0.5 μm were r2 = 0.15 in pasteurized mix storage, 0.11 in the processing area, and 0.13 in the filling area.

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