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AccuFIT 9000 PRO Quantitative Respirator Fit Testing Machine

Quantitative Respirator Fit Test Solutions: Portacount, AccuFIT, and More

By Blog Post

Even though OSHA first accepted quantitative respirator fit testing (qnft) methods in the 1980s, few companies have produced fit testing machines that use those methods. Products like AccuTec’s AccuFIT and TSI’s Portacount are among the only that exist on the market today for employers looking to use the qnft methods to protect their employees.

What is Quantitative Respirator Fit Testing?

Both quantitative and qualitative respirator fit testing are methods used to test how well a respirator mask fits, or how well the seal on that fit holds up to pressure or stress. Respirator fit testing is required for those fields that require the use of respirator masks for the employee and wearer’s safety. Those include fields like:

  • Healthcare
  • Chemical/Lab
  • Military
  • First Responders (Fire)
  • Oil & Gas

OSHA provides standard protocols for respirator fit testing to ensure the safety of those workers.

Quantitative respirator fit testing is the most accurate, reliable, and verifiable fit testing method available. Because quantitative fit testing methods measure the leakage around a respirator mask when it is in use, they result in a data-driven fit factor that is backed by data and verifiable by testers and third parties.

Is Quantitative Fit Testing Better than Qualitative Fit Testing?

While quantitative fit testing uses defensible data to prove the effectiveness of a respirator’s seal, qualitative methods rely on subjective account from the wearer of the mask.

Qualitative fit tests ask the subject of a test to sense a challenge agent by smell or taste and rely solely on the subject’s reporting to determine the effectiveness of a respirator’s fit. That kind of subjectivity is unreliable, often inaccurate, and indefensible.

In short, quantitative fit testing methods are the best options for ensuring the integrity of a respirator and the safety of a mask wearer. 

What Quantitative Fit Testing Machines are Out There?

When you are looking for quantitative respirator fit testing equipment, it is important to ensure that it meets the OSHA standards and CNC protocols. This will help to keep your employees safe when they are masked in the field or in the lab. 

There are some companies out there revolutionizing respirator fit testing with products and product lines dedicated to the quantitative fit testing method. Here are a few that you can trust.

AccutFIT 9000 and 9000 PRO by AccuTec

AccuTec has quickly made itself a leader in the Respirator Fit Testing Market with its flagship products – The AccuFIT 9000 and the AccuFIT 9000 PRO. Both machines offer the latest quantitative fit testing technology and adhere to OSHA’s new CNC protocol.

These fit testers are made to work with any type of respirator including disposable face pieces like the N95 masks. In addition to OSHA, AccuFIT products are compliant with ANSI, CSA, and HSE protocols as well, making them a globally recognized fit testing solution.

AccuFIT gives you the capacity to test multiple units from a single computer or to work with the machine as a standalone without the need for PC operation. Perhaps most importantly, while being among the most effective respirator fit testers on the market, the AccuFIT machines are more affordable than their competitors.


Portacount by TSI

The Portacount was one of the first quantitative respirator fit testers on the market. Like the AccuFIT machines from AccuTec, the Portacount boasts the ability to test many types of respirators including gas masks, SCBAs, respirators, and some models can even test the most popular disposable masks on the market.

The Portacount machines are stand-alone units that do not require a separate computer for operation making them more portable and easy to use.

TSI offers several models of their flagship quantitative fit testing device – the Portacount:

  • Portacount 8030
  • Portacount 8038 – Capable of testing N95 , P1, and P2 disposable masks
  • Portacount 8040
  • Portacount 8048 – Capable of testing N95 , P1, and P2 disposable masks

The models come with various accessory kits and serve slightly different needs. Make sure you read the product details carefully when shopping for a Portacount machine from TSI.


Quantifit by OHD

OHD is also producing a quality quantitative fit test machine in their Quantifit 2 and Quantifit Legacy products.

Unlike both the AccuFIT products and the Portacount products, Quantifit from OHD uses the controlled negative pressure (CNP) method of fit testing. While easy to perform and time efficient, with the approval of the CNC protocols by OSHA, many experts believe that CNP testing is no longer the most effective test available for respirator fit testing.

This video will tell you more about the differences between CNP and CNC respirator fit testing and which method is right for you.

Since Quantifit uses no consumables and air as a challenge agent in its fit testing method, it does offer the unique benefit of allowing you to redon the mask in the process of fitting. Its redon procedure has also been accepted by OSHA as meeting fit testing standards.

Qualitative Fit Testing Methods

The Case Against Qualitative Fit Testing

By Blog Post

Not all companies that use qualitative fit testing as a means to test the fit of respirators may know that the results are not necessarily 100% accurate. If this is the case, there might be a need to look for ways to conduct foolproof respirator fit testing where the results are reliable and verifiable.

Common use of qualitative fit testing in the workplace

Employers in different industries that require the use of facepieces such as respirators and masks are encouraged to follow OSHA’s fit testing procedures (29 CFR 1910.134). A set of safety protocols has been set up to make sure that no contaminant leaks out. Below are some of the workers in the industries that require the use of respirators:

  • Oil and gas industries
  • Chemical industries
  • Military
  • Healthcare

Conducting regular respirator fit testing is required and should be done in accordance with the fit testing regulations. Doing so helps protect workers in industries that deal with health hazards that may include:

  • Chemicals
  • Inhalants
  • Airborne contaminants

Qualitative testing vs quantitative fit testing

When conducting a fit test, there are two ways to identify if the seal of the respirator is functional or not.

  • Qualitative fit testing is highly dependent on the sense of taste or smell using respirator fit testing agents, which means that the results can be subjective and manipulated.
  • Quantitative fit testing is a more accurate and data-driven approach that uses metrics to gauge the fit of the respirator.

Both testing methods apply to different types of respirators:

  • Half-face masks
  • Full-face respirators
  • N-95 filtering face masks

Difference between the two methods of respirator fit testing

Here’s a quick rundown of the comparisons between the two types of respirator fit testing.

Quantitative Fit Testing

Qualitative Fit Testing

Objective, uses metrics

Subjective, results depend on test subject’s responses

Has no room for cheating

Can be manipulated based on inaccurate response

Quick and can be done in less than 3 minutes

OSHA-compliant test runs about 23 minutes

No potential toxic challenge agents are used

Test subjects may or may not have allergies to the challenge agents used

Verification check is available

No reliable means of verification check

A defensible fit test when legal issues against the employer arise

Can be labeled as circumstantial evidence and can be unfavorable for the employer when legal issues arise

Based on the comparison revealed in the table, quantitative fit testing proves to be more accurate and efficient than qualitative fit testing.

Respirator fit testing is a means of ensuring safety and protection at the workplace. This is especially non-negotiable in settings where employees are exposed to health risks. For instance, the clinical staff often wears face masks, because they deal with airborne pathogens. In some cases, they conduct procedures that involve the use of aerosol.

What happens exactly during qualitative fit testing

Qualitative fit testing has two stages. In both stages, testing agents are used and prepared as solutions. 

Testing solutions

The OSHA-approved qualitative fit testing agents are saccharin sodium, BitrexTM (denatonium benzoate), and isoamyl acetate. Note that these are different from the ones used in quantitative fit testing, which are either ambient aerosol (CNC) or controlled negative pressure (CNP).

In a few cases, irritant smoke may be used, so an involuntary cough can be used as a measure of sensitivity. However, the National Institute for Occupational Safety and Health (NIOSH) does not recommend using this test.

Taste sensitivity test

First, the test subject or participant takes a sensitivity test to check their sense of smell and taste. Once the taste sensitivity level has been identified, the participant is asked to wear a respirator so the seal check can be done.

Smell sensitivity test

After completing the seal check, a testing solution will be sprayed in a hood, and sometimes a nebulizer is used. Next, the participant will be asked to follow a series of exercises to check the strength of the respirator seal. Only if the participant is unable to taste the sprayed solution will they pass the test.

Real case of an employer with OSHA safety violations

Fit testing shouldn’t be taken lightly. A hospital in New York learned this the hard way when it was under fire in 2021. Its nurses protested against poor and unsafe working conditions amidst the pandemic.

OSHA did an inspection in May of the same year. As any company might fear, there were violations listed in the inspection report. Three of these were labeled as serious, and they are as follows:

  • The hospital failed to conduct respirator fit testing for all employees who were required to wear respirators, not even for those who were assigned to the progressive and intensive care units.
  • There were no available records of qualitative and quantitative fit testing conducted for employees who were required to wear aspirators.
  • One violation revealed that the nurses wore N-95 respirators without being provided a medical evaluation. The evaluation should have been done to gauge if they are able to use a respirator. All these happened at the time when the nurses were assigned to care for patients who were either suspected or confirmed COVID-19 cases.

This court case is just one of many where an employer didn’t make sure their workers had a safe place to work. Before this, two medical facilities in New Jersey were accused of not following safety rules for respiratory protection.

How qualitative testing can fail employers in legal cases

If you are an employer, the accuracy of test results is one crucial thing that helps you comply with safety regulations. To add to that, it also protects your employees against workplace hazards. Things could go wrong if issues or legal cases arise against an employer in the future. When you fail to present a defensible fit test, the court may not hold a judgment in your favor.

For any company, your records of an accurate fit test are your last line of defense.There is no way to prove that you complied with the regulations in good faith if you fail to show the courts that the fit testing measures you used were reliable. Qualitative fit testing may fail you, and here are the reasons why:

  • These tests heavily rely on the wearer’s or test subject’s honesty.
  • No one knows if the participant’s responses are reliable.
  • No metrics can quantify the data that you need.
  • The records you have on hand may be deemed circumstantial evidence.

Any employer must remember that OSHA regulations and labor code laws are made to protect the welfare of employees. Most of the time, companies are legally responsible when they are accused of breaking safety and labor laws. Any company can avoid fines by staying out of civil cases and having a good track record of results that can be checked and verified.

How quantitative testing can help companies pass any safety inspection

In March 2022, OSHA sent out a memo that explained how it planned to go about inspecting medical facilities that treat COVID-19 patients. The inspection plan was only three months long, but it was very thorough. This was to make sure that medical facilities took the right steps to protect their employees from the dangers of the coronavirus. 

It is possible another set of inspections will be carried out in the future. As a safety measure, companies can avoid being charged with safety violations if they do fit testing correctly. The best way to make a defensible fit test is to choose a method with better documentation. This way, results can be checked. With better documentation comes better compliance.

Also, quantitative fit testing solutions such as those offered by Accutec can solve many problems that employers face. Here are some examples:

  • A series of tests/exercises in the standard testing procedures are eliminated to save time
  • Manpower for qualified fit test administrators is no longer an issue
  • Scheduling employees to test respirators when there is a critical staffing shortage is avoided
  • Respirator fit testing in small facilities with limited space is no longer troublesome
  • Urgent fit testing can be done amidst work settings where COVID-cases are rampant
  • Fit testing may be done often, even in circumstances where facial structure changed or when there is the presence of facial hair
  • Closer monitoring of all employees is achieved to maintain a higher level of safety and protection

Finally, should a case against an employer arise, the quantifiable, verifiable, and defensible data derived from a quantitative fit test protocol holds up as solid evidence of OSHA compliance.

What companies need to know about fit testing

Carrying out fit test methods that are time-consuming and have a high margin of error takes a lot of employee productivity time. Moreover, when things go awry, the way you do things may prove to be fallible.

Employers need to understand that proper respirator fit testing is essential to saving lives. This is why not only safety but also the accuracy of testing methods should be one of any company’s top priorities.

Make sure you are doing everything you can to both protect your employees and protect your company by using only the best quantitative respirator fit test machines available

Disposable respirator fit mask with proper face fit

Respirator Fit Testing Mandate: Yea or Nay?

By Blog Post

Very few people like mandates, but there are many that make sense. For instance, restaurants are required to meet certain standards of cleanliness and sanitation to stay open and functioning. Commercial airline flight crews have to demonstrate proficiency in their ability to fly passenger-carrying aircraft by earning an Airline Transport Pilot rating and a First-Class Medical certificate. Healthcare professionals must be certified and licensed in their field in order to be able to practice.

Anyone out there want to eat at a disreputable restaurant, fly with an untrained pilot, or be operated on by an unlicensed doctor? Not likely.

We tend to take these things for granted, but in reality, these protections exist because they are mandated.

Why are Fit Testing Mandates Required?

The common misconception about respirators (including and especially N95 disposable respirators) is that if someone wears a respirator, he or she is protected from whatever toxic or infectious agents are in the ambient atmosphere in which the person is working. While this may be true, the only way to be sure the wearer is protected is to know that the correct filtration is employed and that the respirator fits!

OSHA has mandated in 29 CFR 1910.134 that whenever a respirator is required to be used to protect an employee (and there are some very specific requirements in the regulation), the respirator must be fit tested to ensure that it actually fits the employee sufficiently well to achieve a minimum protection( fit) factor.

Respirator Fit Testing Mandate Protects Us

Fluid dynamics tells us that a fluid (like air) will flow through the path of least resistance. If the respirator does not seamlessly fit the face of the wearer, a very large part of the air entering the breathing zone will have done so by bypassing the filtration and entering past the margins of the respirator, most likely through gaps around the edges. Toxic vapors, infectious aerosols, and particulates will be carried into the breathing zone along with this air flow. The only way to be sure that this does not occur is to rigorously test the fit of the respirator, and the only way to unambiguously do so is by using a Quantitative Fit Test.

Wearing a respirator that doesn’t fit is dangerous. This is obvious, but even worse, it can create a false sense of security on the part of the wearer. He or she may then take risks they might not otherwise have taken while wearing improperly fitted pieces of personal protective equipment.

What Is the best way to test the fit of a Respirator?

A Quantitative Fit Test (QNFT) such as is produced by the AccuFIT 9000 series of instruments does not depend on the ability of the test subject to detect a challenge agent such as saccharine. QNFT is completely objective and produces a defensible metric that can be referred to by the employer and test subject as proof that the respirator fits and will do the job it was designed to do.

As we said, few people like mandates, but this one, Respirator Fit Testing, saves lives, so we vote Yea!

N95 mask types

The Real Problem With Mask Mandates

By Blog Post

N95 mask types

Even N95 Masks Require Respirator Fit Testing

With the rise of the omicron variant, many States and businesses are enforcing mask mandates.

Whether or not you agree with these mandates, the real question is…do they make sense when many masks are ineffective?

Based on our experience, we think not.

Not All Masks Protect The Wearer

Cloth masks do little or nothing to protect the wearer from infectious aerosols, and mandating wearing these makes no sense.

Even surgical masks that do a pretty good job of protecting everyone else from the wearer aren’t 100% effective. Fluid mechanics tells us that any fluid (like air) will flow through the path of least resistance, and since surgical masks do not actually seal to the face, most of the incoming air enters around the mask rather than through it.

It’s the Fit That Counts

What does make sense instead of issuing a mask mandate, is requiring that well-fitted N95 masks be made available, especially for medical and emergency-response personnel. And the key phrase here is “well-fitted” which means that the N95 respirator (brand, model, and size) must be fit-tested!

A user could be wearing the best-filtering N95 in existence, but if the respirator doesn’t fit, it’s effectively useless, allowing more air around than through the mask. Even worse than providing little to no protection, the ill-fitting mask gives the wearer a false sense of security, potentially leading them to take risks they might never have if they’d known their respiratory system was unprotected.

How Does Respirator Fit Testing Work?

There are two types of fit testing available when it comes to most respirators – qualitative and quantitative.

Qualitative fit tests rely on a test subject’s ability to sense a challenge agent (usually saccharine) while wearing their mask. But unfortunately, this produces absolutely no defensible metric that can be referred to for proof of effectiveness of fit. This type of testing is completely subjective and therefore can lead to a questionable result as far as the actual fit of the respirator is concerned.

Quantitative Fit Testing is completely objective, so the results can be relied upon to accurately measure whether or not the N95 (or other respirator) actually fits the person on whom it is being tested. Once the fit test shows a passing score, the healthcare worker or emergency response worker can take comfort in knowing they are truly protected.

Mandate fit tests for at-risk personnel, not useless cloth masks.

To learn more about quantitative fit testing, check out our Quantitative Fit Testing Guide here.

Cartoon scientist with half-mask respirator and proper face fit

What is Quantitative Respirator Fit Testing?

By Blog Post

Quantitative respirator fit testing measures how much air leaks into any tight-fitting respirators. Each quantitative fit test is performed by using a machine that calculates measurements with one of two methods: ambient aerosol (CNC) or controlled negative pressure (CNP). For nearly 30 years, there were only two manufacturers capable of performing the OSHA fit test protocol.

Which Respirator Fit Testing Method is Best?

The CNP method requires the wearer to hold their breath and stand still for the duration of the test, while the CNC test allows the wearer to be tested in a dynamic manner.

With over 75 years of combined respirator fit tester experience, we know if a respirator is going to leak, it will most likely do so while the wearer is talking, breathing, moving their head and/or performing basic work functions, not while holding still.

Respirators are used in a wide range of industries, from chemical and medical fields to first responders, oil and gas industries, and even in the military. Making sure they fit the user perfectly is essential to each user’s health and safety.

We use quantitative fit testing with the CNC method on all of our instrumentation to ensure the most accurate fit test measurements.

What Respirators Can Be Tested With the Quantitative Method?

Our instruments work with all types of respirators, including full and half-face respirators, filtering face piece respirators like N95 masks, and even disposable masks and respirators. During the test, the user is required to move around and breathe as normal.

What Is The Most Effective Quantitative Fit Tester Available?

In fact, our own AccuFIT 9000 Pro is the world’s most accurate tool for quantitative respirator fit testing. Compliant with OSHA’s streamlined 2019 CNC protocol as well as ANSI, CSA and HSE, it works with all respirator types, including N95, P100 and N99, FFP1, FFP2 and FFP3.

This model comes standard with several unique features, including standalone mode, built-in wifi, and some unique programming, which allows us to be the first respirator fit tester on the market with wireless operator mode. Wireless operator mode allows a person to control one to four units with a tablet, with independent start and stop times. All this can be done concurrently as instructions are relayed to the fit test subject on the built-in display of the instrument.

The AccuFIT 9000 Pro also has the option of a separate battery pack for portable testing in the field. Plus, it’s backed by a three-year warranty.

Using AccuFit 9000 machines like the AccuFit9000 Pro, fit testing takes just minutes and ensures a direct fit every time.

Doctor in thought

How Viruses (like COVID-19) Can Affect Qualitative Respirator Fit Testing Results

By Blog Post

The Qualitative Respirator Fit Test is a method that relies on the ability of the test subject to detect a challenge agent such as Saccharin. It has been in use for decades and predates the evolution of Quantitative Fit Testing methods and equipment.

Qualitative testing assumes that if any amount of the challenge agent penetrates the respirator/face seal the test subject will taste or smell it. The test is conducted while the test subject is wearing a hood into which the challenge agent is aerosolized. There are several factors associated with this method which can and have been proven to occur, chief among which are:

  1. Extreme variations in different subjects’ ability to taste or smell the challenge agent
  2. Truthfulness or confusion of test subjects in reporting whether or not they can sense the challenge agent
  3. Onerous physical requirements in the protocol and now, continuous decontamination between tests which tend to encourage “short cuts” in the execution of the test, and
  4. The complete lack of any defensible metric such as the Fit Factor data that is collected and recorded by the Fit Test device when performing a Quantitative Fit Test.

The first concern, that of the wide variation in the test subjects’ ability to detect the challenge agent, is exacerbated by the generally recognized fact that many persons who are infected with the SARS CoV-2 virus which causes Covid-19, even if asymptomatic, can experience greatly reduced olfactory sensitivity. One can easily imagine a situation in which an asymptomatic but infected individual would be tested by using a challenge agent for which they have a greatly reduced ability to sense.

A 2020 article in Scientific American by Leslie Kay, Ph.D. addresses both the mechanism of this olfactory dysfunction and the fact that it can exist in asymptomatic individuals.

The concern is that the already-problematic qualitative test now has another reason to distrust the results; virus-induced olfactory dysfunction (medical term: Anosmia).

A Quantitative Fit Test using the new streamlined OSHA 2019 standard can be conducted in about two and a half minutes.  The results are completely objective, produce a defensible metric, and are not affected by any impaired sense of taste or smell.

NIH recently released this information which presents a very serious statistical evaluation of the reduced sense of smell in the population of the US.

An infographic summarizing information and statistics on the sense of smell in U.S. adults over age 40.

For more information about the advantages of Quantitative Fit Testing compared to Qualitative, please feel free to contact us here.

Cartoon of the genius of n95 filtering facemasks

How N95 Masks Really Work

By Blog Post

There is a lot of misinformation about the way N95 respirators work and in fact what the designation actually means. In order to understand the  AAC/CPC method of fit testing, it is really helpful to first understand the filtration mechanisms that occur in the Filtering Facepiece Respirators such as the N95 series.

We recently found this video, which does an excellent job of explaining the physics of the N95.

In fact, we were so impressed by the very straightforward explanation of the filtering mechanisms that we asked the production company for permission to link to the YouTube video, which they graciously granted.

The video contained in this link is meant for educational purposes only and was produced by ‘MinutePhysics’ who are solely responsible for its content and messaging. You will be redirected to the MinutePhysics YouTube Channel to view this very informative piece about the physics and performance characteristics of N95 respirators.

Covid Virus on Door Handle

How Long the COVID Virus Can Live on Surfaces

By Blog Post

One of the many important things to know about the particular strain of coronavirus which is the etiological agent of the current pandemic is the length of time the virus can remain infectious when it is in the environment. This exceptionally well written and documented letter was published in the New England journal of Medicine which gives some pretty clear answers which everyone should know.

Unfortunately, on relatively inert surfaces such as plastics and stainless steel the virus is sufficiently robust to have a half-life such that it probably is infectious up to 72 hours after deposition. Copper surfaces are more active, and the viability seems to be about 4 hours. What is most concerning (at least to me) is that apparently the virus can remain viable in aerosol droplets for up to 3 hours.

This is why healthcare workers who may be exposed to infected (and infectious) individuals should seriously consider respiratory protection.

We at AccuTec-IHS want to once again stress the fact that merely wearing a respirator (such as disposable N95’s, N99’s or N100’s) isn’t enough. The respirator must have been properly fit-tested. A quantitative fit test such as the fit test performed by the AccuFIT 9000® can truly prove that the mask fits and that the person wearing it knows how to deploy it properly.

We at Accutec-IHS are monitoring the situation constantly, and are doing all we can to keep up with demand.

Questions or comments? Let us know here.

CNC vs CNP Fit Testing Comparison and Explanation

The Difference Between CNC & CNP Fit Testing

By Blog Post

Two Quantitative Fit Testing Methods

Respirator fit testing is becoming more important all the time. There are two methods for performing quantitative fit testing, Condensation Nuclei Counting (CNC) and Controlled Negative Pressure (CNP). So, what’s the difference? 

There are essentially two methods currently in use to perform quantitative fit testing of tight fitting respirators:

CNC Fit Testing

The most widely used method is the ambient aerosol method using CNC. This test is done by challenging the seal of the respirator with naturally occurring, ultra fine particulates. The extremely low mass characteristics of these particulates mimic gas molecules. 

CNP Fit Testing

The CNP method pulls a slight negative pressure inside the mask and then measures the exhaust to determine how much more air must be pumped out in order to maintain that same low pressure. 

While both methods are approved by OSHA and are in use today, they are not created equal. So which method is better for your respirator fit testing needs?

CNC vs. CNP: Pros and Cons?

When comparing these methods, it’s best to examine the pros and cons of how each method is carried out, what factors may impact the results, and how accurate and repeatable those results are likely to be.

CNC Fit Testing Method Pros

The CNC testing system measures the concentration of ultra fine particulates in the ambient atmosphere and then measures the concentration of these ultra fines, a.k.a. respirable particulates in the breathing zone of the respirator. While the test subject is actually moving and breathing. Then this system measures the ambient concentration, again, computes an average of these two values and compares that value to the concentration inside the breathing zone.

That number becomes the fit factor, which is a real measure of how well the respirator actually fits. And because these particulates are respirable – can be breathed safely – using these ambient aerosols are perfect for use as the challenge agent in these tests. 

If the respirator being tested is set up with a HEPA filter in the inlet in about a minute, the concentration ACE approaches zero then any new particulates observed in the breathing zone penetrated past the respirator seal. 

Finally, and perhaps most importantly, the CNC method can be used with disposable filtering facemask respirators like the N95, whereas the CNC method cannot.

CNC Fit Testing Method Cons

Historically, CNC testing methods took significantly longer than CNP methods. This made it difficult and expensive for larger organizations to schedule mass testing. As a result, the CNP method quickly became the standard for quantitative respirator fit testing.

With the newest protocols approved by OSHA, however, CNC testing methods can now be done in less than 3 minutes. 

CNP Fit Testing Method Pros

The way the CNP system measures the pressure inside the respirator is by using a very sensitive pressure transducer. When the pressure rises, the system runs the vacuum pump and measures the amount of air in the exhaust. Theoretically, that measure is equal to the amount of air which is leaked past the respirator seal.

The sensitivity of the transducer and the clearly measurable results are both major positives and give this method an advantage over qualitative fit testing methods.

CNP Fit Testing Method Cons

While theoretically sound, there is a major flaw to this testing method. That is the human element. More specifically, it is the test subject’s breathing. The subject’s breathing affects the pressure in the mask zone and can throw off the pressure measurements, rendering the results null and void. 

So the test subject has to hold his or her breath while the leak rate is measured. Furthermore, the test subject cannot move at all or the pressure will change slightly and the system will interpret that change as a leak. 

Since people move and breathe when using their respirators on the job, this testing method is not a good correlation to actual use. Even if a test subject manages not to throw off the measurements, this testing method is hard to trust as the seal on a respirator is challenged much more when the wearer is active than when they are still.

So Which Quantitative Fit Testing Method is Best?

Since OSHA adopted the newest Fast Fit Testing Protocols, the biggest con for CNC testing has been eliminated.

With more reliable results, better correlation to real-world application, and fewer ways to skew the results, CNC fit testing methods have become the best quantitative fit testing method available. 

Keep your employees safe using the newest and best CNC quantitative fit testing methods and equipment from Accutec IHS.

AccutFIT9000 Respirator FIt Testing Kit

How to Setup the AccuFIT9000 Fit Testing Machine

By Blog Post

Video Transcript

Hi, I’m Wesley with Accutec-IHS. The AccuFIT9000 is a new instrument for performing respirator fit testing which depends on measuring the fit of a tight fitting respirator by comparing the ratio of the respirable particles in the breathing zone, with the concentration of these ultra-fine particles in the ambient atmosphere. This technology is called condensation particulate counting. To learn more, watch the video condensation particulate counting on the AccuFIT9000. 

          Let’s ensure the instrument is working properly, remove the instrument from the carrying case and locate the power supply AC cord, alcohol capsule sample tubing, and HEPA filter. Plug the power supply into an electric outlet. Connect the power supply and plug the connector into the port on the back panel of the AccuFIT9000. Next, remove the alcohol wick assembly from the capsule and place it on a clean surface. Then pour reagent grade isopropyl alcohol which is supplied with the instrument into the capsule so that the level of liquid is above the bottom line and below the top line. Replace the alcohol wick into the capsule and allow the alcohol to saturate the wick. This takes about two minutes. Remove the wick assembly from the capsule and tap off any excessive alcohol. Then remove the storage cap from the AccuFIT9000 alcohol port and replace it with the saturated alcohol wick. The locating pin and camming groove on the cap will guide the wick into its proper location. Now attach the sample tube to the a AccuFIT9000 making sure that you attach the blue tube to the blue inlet and the clear tube to the silver Inlet. Attach the HEPA filter to the clear tube making sure that the arrow showing flow direction is pointing toward the tube. Now press and hold the on/off button on the AccuFIT9000 until it illuminates with a red light. Allow the instrument to complete its warm-up and internal self checks. This takes about a minute and then will automatically transition to the opening screen.  The on/off button will now illuminate green. Touch the administration icon and then select the database icon using the drop down arrow. Highlight demo and then touch the load button. A message should appear telling you that the database demo is successfully loaded into active memory. Please note that the demo database does not allow you to perform all of the functions to test the instrument. It does not allow you to add names, respirators, or protocols to memory, nor does it allow you to save any results obtained. Press exit and then the return arrow on the previous screen. This returns you to the opening screen.

          Now it is time to test the functionality of the AccuFIT9000. Touch the icon labeled validation check, remove the HEPA filter from the clear tube and press start. The AccuFIT9000 will now measure the ambient particles and produce account. The validation check will now ask you to replace the HEPA filter into the clear tube and press next. The validation check will proceed automatically to check that there are no internal leaks in the system, that the switching valve is functioning properly, and that the unit can calculate the max fit factor. You have now demonstrated that the AccuFIT9000 is performing as designed. To shut down the instrument, hold the on/off button until it flashes red and green and touch the yes box. It is very important to remove the alcohol cartridge and replace it with the storage cap. Failure to remove the alcohol cartridge can result in alcohol contamination of the optics. Replace the alcohol cartridge into the   capsule. This ensures that there will be no spillage and that the alcohol cartridge will be ready to use the next time you want to perform fit testing. If the AccuFIT9000 is to be stored in the carrying case, remove the sample tube and power connector, and place the cutouts in the protective foam insert and position the instrument appropriately.