Bulk and Tapped Density 

Introduction to Bulk and Tapped Density

The bulk density of a cloth is that the ratio of the mass to the amount (including the interparticulate void volume) of an untapped powder sample. The tapped density is obtained by mechanically tapping a graduate containing the sample until little further volume change is observed. 

Instrument and measuring principle 

The bulk density is given in g/ml. the majority density depends on both the density of the powder particles and on the arrangement of the powder particles. the majority density is influenced by the preparation, treatment and storage of the sample material. how for measuring the majority and tapped density of powders is described within the Pharmacopoeia chapter 2.9.34.

More about the methods

Bulk method 1: the majority density is obtained by adding a known mass of powder to a graduate .The density is calculated as mass/volume. 

Tapped method 1: tapped density is get from mechanically or manual tapping a graduate inclusive the sample until volume change is seen.The tapping are often performed using different methods. The tapped density is calculated as mass divided by the last word volume of the powder. The interparticulate interactions that influence the bulking properties of a powder also are the interactions that interfere with powder flow. it's therefore possible to know information about the relative importance of those interactions during a given powder by comparing the majority and tapped densities, and such a comparison are often wont to index the power of the powder to flow. During a free-flowing powder these interactions are smaller and thus the bulk and tapped densities are becoming to be closer in value. The differences are reflected within the compressibility index and Hausner ratio.

From a basic purpose of read, each the stratified Air Flow cupboard and therefore the Biological Safety cupboards merely providing completely different levels of protection. numerous aspects of protection offered ar hooked in to the sample, the atmosphere, and therefore the user as ar protection compartments however well.

It is necessary to illustrate that whereas the stratified Air Flow solely protects the merchandise within the chamber, the Biological Safety cupboards protects each the merchandise and therefore the user from microorganism protection. This forms the key distinction between the 2. to the current result, the safety cupboards proves to be ideally higher and versatile. the 2 instrumentality, however, bear different variations supported their usage, practicality and different aspects as explained below.

Safety cupboard employs the HEPA filter mechanism in its system that traps completely different mobile materials. The mechanism is organized in accordance with the direction of flowing to realize product protection and different environmental protection ideas. Secondly, the safety cupboard bears a sash that helps in processing away the air from the user by use of a grill-work mechanism. This makes it a perfect piece once addressing probably infectious agents. This additional makes it ideal for acting later, the Biological Safety cupboard recycles regarding seventieth of the air and purifies the air particles by use of the HEPA filter mechanism. in an exceedingly shell, the key purpose of the safety research lab cupboard is to supply protection to each the non-infectious tasks too. user and therefore the atmosphere from bio-hazards and different styles of infectious agents. It additional protects analysis materials from infectious and mobile contaminants by use of HEPA filters.

Laminar Air Flow it's necessary to notice that the stratified Air Flow in 2 major varieties, the cupboard comes horizontal and therefore the vertical. the various options ar thereby variant on the usage. Generally, the stratified Air Flow cupboard has AN open face and therefore the air is directly blown towards the user via the grill-work. For this reason, it ought to solely be used once addressing non- infectious materials. This additional makes it not ideal once operating with biohazards. For the Horizontal stratified Air Flow instrumentality, the clean-air bench principally used once acting cell cultures bears a high probability of exposing users to infectious material like aerosols. The vertical stratified Air Flow instrumentality later blows air out which can cause exposure to matter materials. Further, the air flow mechanism of the stratified Air Flow is disturbed by even the slightest act of inserting or retreating of the hand into clean bench work-space. This obstruction causes turbulence within the flow of air typically leading to dirty air coming into from outside.

Air Flows, however, specifically designed to reduce the doorway of dirty air by use of slots on the perimeters of the space. Ideally, the stratified Air Flow cupboard specimen protection microorganisms and additional provides clean-air operating area to necessitate biological safety. Some stratified ar offers basic from once and for all, the foremost variations between the 2 items of the 2 laboratory instrumentality ar strictly hooked in to the precise wants still because the completely different levels of protection required.

Q. What will the term HEPA mean? A. HEPA is AN signifier for "High potency Particulate Air" or "High potency Particulate Arrestance." This signifier refers to a filter that's factory-made, tested and authorized to satisfy Institute of Environmental Sciences and Technology (IEST) construction, performance presently and certification standards as revealed in IEST RP-CC001.3. Q. however long have HEPA filters been in use? A. the primary HEPA filters were developed for the nuclear energy Commission throughout warfare II to be used in facilities producing elements for the Manhattan (atomic bomb) project. These HEPA filters were originally designed to capture microscopic radioactive particles too tiny for effective removal by existing kinds of filters. HEPA filters used these days ar rather more economical and economical than the product created within the 1940's.

Q. wherever ar HEPA filters used today? A. HEPA filters ar usually such for applications particles or bio-pollutants may cause human health or product quality issues. Typical users embrace military, nuclear, pharmaceutical, physics, biological and medical facilities. Related: HEPA Filters employed in prescription drugs Q. what's it that produces HEPA filters thus wherever microscopic mobile efficient? A. The ultra-fine glass-fiber medium captures microscopic particles that may simply go through different filters by a mix of diffusion, interception and mechanical phenomenon impaction. To qualify as a kind A HEPA filter, the filter should capture a minimum of ninety nine.97% (9,997 out of ten,000) of particles zero.3 microns in size-about three00 times smaller than the diameter of an individual's hair, and twenty five to fifty times smaller than we are able to see. To a HEPA filter, catching a one-micron particle (1/1,000,000 of a meter) is like stopping a plant disease with a door screen.

Q. ar filters this economical very necessary for IAQ applications? optical device particle counter generally show that over ninety nine of the particles suspended in indoor air ar one metric linear unit (1/1,000,000 of a meter) or smaller in size. EPA calls these "lung-damaging" particles as a result of they'll lodge deep within the lungs once inhaled . the power of HEPA filters to capture particles this tiny is what sets them except different kinds of filters. rules developed by EPA, OSHA, CDC and different federal, state and native A. measurements government agencies chargeable for human health and IAQ problems specify HEPA filters for amphibole, lead and mould abatement, TB and SARS isolation rooms and aid renovation comes. Q. ar all filters created with HEPA filter media HEPA filters? A. producing a filter with HEPA filter media doesn't mean that the filter itself meets true HEPA potency needs. Serious filter outpouring will go unobserved severally tested and authorized at the top of the producing method. Even the tiniest puncture filters don't seem to be leaks within the media or breach of the seal between the media pack and therefore the filter frame will cause the filter to fail IEST needs. The testing needs terribly specific procedures employing a thermally generated mono-dispersed aerosol and a optical device particle counter.

Q. Why is testing through with a zero.3-micron particle size check aerosol? A. Filter potency studies have shown that zero.3- microns is that the "Most Penetrating Particle Size (MPPS)" for HEPA filter media. potency is often bigger than ninety nine.97% against larger or smaller particle sizes. Particles larger than zero.3 microns ar generally additional simply at bay or intercepted, by the media. Smaller particles typically lack enough mass to penetrate the media. Q. may be a "HEPA Type" filter identical as a HEPA filter? A. No. In fact, the variations ar Brobdingnagian. in keeping with the yankee respiratory organ Association, filters classified as "HEPA type" filters might capture as very little as fifty fifth of zero.3-micron particles (5,500 out of ten,000). By this definition, actuality HEPA filter can be over one,800 times as economical because the "HEPA type" filter. Q. will HEPA filter potency decrease because the filter gets dirty? A. No. not like electronic air cleaners and different air purification technologies that have substantial loss of potency as they become dirty, precisely the opposite generally happens with HEPA filters.