QuantiFit2 Hardware

           Yes, the QuantiFit2 may be used outdoors. It is not designed to be used in inclement weather such as rain, sleet or snow. The QuantiFit2 is for use at a temperature range of 5°C to 45°C (41°F – 113°F), maximum relative humidity of 80% non-condensing and pollution degree 2.

The HP 200 and HP 250 mobile printers work with our QuantiFit2.  You can click the link here to see a full list of printers.  

In the Settings menu, click on “Setup Respirators.” Click on the plus sign (+) and enter the respirator information.

In the Settings menu under Admin Menu, there is a button for “Change Regulation.” Click on this button, select the preferred regulation, and click the green checkmark.

In the Settings menu, click on “Setup Respirators.” Click on the purple plus sign and enter the respirator information. The inhalation valve question is to indicate whether that prompt needs to be displayed or not.

In the Settings menu under the Admin Menu, click on “Setup Operators.” Click on the plus sign (+) and enter the appropriate information. This is also where you can designate an operator as an administrator. 

In the People/Test screen, select a person from the list, and click on the pink “History” button. A list of all tests related to this person will show in a list to browse through, export, or print.

This is a setting that automates how a fit test is started. The person being tested needs to take a breath large enough for the circle on the screen to turn green and then hold their breath. The test will begin on its own and there is no need for the test subject to do anything other than to continue to hold their breath until the step ends after 8-10 seconds.

Auto Advance will move to the next test step when the current test step has passed. If the test step fails, there will be an opportunity to save that step or retry the step.

DATABASE: In the Settings > Admin Menu, there is a selection for saving the entire database to a jump drive.

RECORDS: To save test records this can be done from a person’s record, or through the report section.

  • Through an individual’s records, the History button will show the tests that belong to this person, and each one can be printed individually.
  • In the reports section, reports can be printed for groups or individuals selected by date and/or company.

The Seal Check button allows a test subject to perform a user seal check with the assistance of the QuantiFit2. When the Seal Check button is held down continuously, an internal pump will seal the respirator. This will not draw a negative pressure. Once the mask is sealed, the wearer can perform a positive and/or negative pressure user seal check.

The amount of records the QuantiFit2 can hold is virtually unlimited from a practical standpoint. The internal storage should allow hundreds of thousands to millions of test records to be stored.

In the Settings menu, under the System Info section that contains details about the instrument. There are Current Date and Current Time fields that can be changed by pressing on one of the values.


The software can be found on our Downloads Page. On this page you will find the version number and date of release. The software may be downloaded and shared with other computers within your company.

      Windows Version 10 or greater
      Processor Speed: 1.0 GHz or greater
      RAM: 1 GB or greater
      Disc Space: 16 GB

OHD Logic software will be updated periodically to enhance features, add features, or fix bugs. In the Settings section, there is an option to automatically receive updates. If this feature is turned on, you will be notified when the program is launched, and the PC is connected to the Internet. If this is not turned on, whenever the Update menu is selected, the software will check to see if an update is available and there will be an option to update or not. Software updates will typically install “on top of” the current installation and an uninstall will not be required. However, if an uninstall is required for any reason, this will not affect the database. It is best practice with any software to back up data when updating or uninstalling a program.

Yes. The installation must be completed by someone logged onto the PC who has administrative privileges.


When the operator is experiencing difficulty getting anyone to pass on these masks, the answer typically lies within the Scott Connector, p/n 200423-01. It is recommended that the operator keep a spare part, and replace them at minimum once each year.

Please follow these instructions when fit testing with this Scott Connector with our Kit #1 part number 9513-0130.  

  1. The connector must be modified to be used for fit testing, and once modified, it must not be used during the need for a respirator.
    1. There are two valves that must be removed, a clear circular valve on the bottom, and the valve that can be seen when looking into the opening where the OHD adapter will be threaded into.
    2. The threaded opening must have a rubber washer, but you must be able to clearly see into the connector.
  2. The exhalation valve is dirty
    1. This can occur even when the part is brand new
    2. You must remove the rubber sleeve that protects the exhalation valve.
    3. With water or a mask wipe, clean the underside of valve as well as the circle on which it rests
  3. Foam pad is worn out
    1. Over time, the foam pad that creates the air-tight seal against the mask, can lose its cushioning ability.
    2. This foam pad can lose elasticity whether it is being used or not, and many times is revealed when a company begins the fit testing for the year.
    3. The concnetric circles where the pad connects to the mask, get more and more compressed over time and lose their air-tight function.
    4. If the company has a certified Scott technician, the technician can replace the foam pad. If not, the entire part must be ordered.
    5. One sign that the foam rubber is too old, is when a first step or first person might pass, but every following test produces a failure.

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Please follow instructions when using Draeger Mini Rap connector 4055505 with OHD Kit #1 (9513-0130) fittest adapter.

This combination will work with any snap-in connection on a Draeger respirator.

To prep the Rap Adapter, you must remove the spokewheel (1) on the threaded side, remove and discard the flat diaphragm (2) and then reinsert the spoke wheel gasket (3).

The Kit #1 adapter will screw into the threaded side of the Mini Rap adapter, and opposite end of the Rap (with the O-ring) can be inserted into the front of the respirator until it clicks into place.

The only maintenance required on this Rap adapter is to be sure the rubber gasket remains clean. This part will last for many years with normal use.

The Inhalation valve must be removed from the ISI part #171138. (Image shows part without diaphragm.) This is an orange/red diaphragm that is attached to the under-side of the cross-hair plastic.

The 171138 must be attached to the front of the respirator. First you will remove the front portion of the respirator by unscrewing the 4 screws. The inside hex nut uses a 5/16 nut driver and the outside uses a 3/32 allen wrench. The 171138 will replace the front portion of the respirator.

After the 171138 part has been attached to the respirator, prop or remove the inhalation valve, then attach Kit #1 into the female threading.

Since this ISI piece is not easily moved to another respirator, ideally you will want to have surrogate masks in each size of the respirator. The OSHA fit test requirement is that you must have one of each size for the test subject to try.

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Testing the MSA Ultra Elite respirators requires the OHD Kit #38, 9513-0380.

  1. Regulator must be removed from mask for fit testing.
  2. Insert adapter into the front opening of the mask, and the O-rings will create an air-tight seal. (Fig. 1)
  3. The silver prongs will prop open the inhalation valve to prepare the mask for testing. Do not twist the adapter on the mask or it could do damage to the gasket in the mask.
  4. Connect the clear tubes to the two-connector side and the blue tube to the single- connector side (Fig. 2)
  5. Perform fit test

There are two things to look for if you are having trouble getting people to pass with this respirator.

  1. Make sure that the bottom of the adapter says “Rev B.” If it has no Rev, or Rev A, Contact OHD to update your adapter.
  2. When the adapter is twisted onto the side of the mask, there is a natural stopping point. You must then turn harder so that it will travel another quarter inch. If left at the first stop, the adapter will not make an airtight seal.

This problem could include a number of variables, but most likely would fall into three categories: machine fault, adapter/mask fault, or subject/operator error. If it’s a one-time problem when you are able to pass other people, the answer simply may be that the mask is not a good fit on the subject. When several subjects can’t pass, you must look at the other variables.

Machine Fault:

  1. You must do the daily calibration at the beginning of each day.
  2. If the QuantiFit2 successfully completes the dual tube calibration without an error message, this assures that the machine is operating properly and within tolerance.
  3. If the QuantiFit2 does not complete the dual tube calibration, service might be needed. Please contact OHD customer service.

Mask/Fit Fault:

  1. You must first determine that there is a proper fit. Any facial hair, hair getting anywhere under the mask seal, temple hair too far forward, sunken temples or facial scarring, protrusions or blemishes, having the mask too loose or too tight, can all be reason enough to keep the Quantifit from pulling a negative pressure within the mask. There are other obstacles that can come into play which are too numerous to list. With more experience fit testing, it’s easier for one to see potential problems with fit.
  2. To further check on the mask fit, do a user seal check for 10 seconds. Press the Seal Check button and take in a breath allowing for plenty of suction on the mask. If after 10 seconds the mask “drops” when releasing the Seal Check button, then there was a good seal in place. If there is no felt movement when the Seal Check button is released, then the air has leaked out in those 10 seconds.
  3. Exhalation valves may be dirty or creased allowing air to be pulled into the mask. While the inhalation valves must be removed or propped open, the exhalation valve must remain in place and maintain a good seal.
  4. On the mask, the apex of the head straps should sit on the crown of the head and not off to one side or the other.

Adapter Fault:

  1. The adapters must be kept clean and in good shape.
  2. Disconnect and reconnect all tubes to make sure they all “snap” into place for a secure connection
  3. For our OHD adapters, make sure all eight screws are tight as well as the quick connect posts that the tubes attach to.
  4. If the adapter had been dropped or crushed, a hairline crack might cause leakage.

Operator/Subject Error:

  1. Holding breath. The most obvious error that could take place is when the subject does not remain completely still. He or she must be instructed to hold breath, keep lips and teeth together, no swallowing, etc. Tell the subject to hold a comfortable breath. When holding a deep breath, there is more air fighting to get out of the lungs, and this could cause movement or actually be more of a challenge for the subject to hold. The QuantiFit2 is very sensitive and will even register slight head movement.
  2. If the Trigger button is pressed while the test subject is still breathing or inhaling, the QuantiFit2 will display a message stating that the breath must be held before the measurement can begin.

If it’s only one or two people who won’t pass, but others are passing, this would indicate:

  1. A poor fit, try a different size or brand of mask.
  2. Hair, not clean-shaven, scar, or some other impediment may be breaking the surface of the mask.
  3. Test subject not holding breath properly.
  4. In rare cases, the test subject might have a hole or defect in his or her eardrum.
  5. Dirty mask/exhalation valve. Even if the valve does not look dirty, wipe the inside of it with a wet finger or cloth.

If there is an inhalation valve inside the mask where our adapter connects to the mask, this will definitely interfere with the testing procedure. To begin the test, the QuantiFit2 first exhausts air out of the mask to get to the target negative pressure. If the inhalation valve is in place, the QuantiFit2 will not be able to pull air out of the mask because the suction will pull the valve shut. This usually shows up on the graph as a lot of up and down movement when the test begins.

If it’s easy enough to remove the valve and replace it, we suggest doing this. If it’s difficult at all, you can prop open the valve before the test. If you have a two-adapter kit, the critical one is the side with the two ports on it. We sell a Valve Prop that can be used to keep open the diaphragm. If you do not have a valve prop, a good substitution would be to cut a drinking straw to approximately two inches. Fold this in half so that it makes a V. Insert the open end of the V into the spoke-wheel gasket that holds the diaphragm in place. You can achieve the same results with a rolled-up piece of paper.

Of course, you’ll want to remove this prop after the test so that the mask is back in its original form.

OSHA 1910.134 Appendix A:

“4. (a) (4) The respirator filter or cartridge needs to be replaced with the CNP test manifold.
The inhalation valve downstream from the manifold either needs to be temporarily removed
or propped open.”

QuantiFit2 eliminates the need to delay testing on mask users that have just eaten or smoked. You can test immediately with QuantiFit2. The QuantiFit2 CNP technology enhances logistics by simplifying employee requirements prior to testing.

The Controlled Negative Pressure technology of the OHD QuantiFit2 allows the mask to be challenged in ways that are impossible, or at least impractical, for other systems. Because we use negative pressure to replicate the negative force of inhalation, the OHD QuantiFit2 can be set to increase the negative force in the mask to replicate breathing rates of over 100 liters of air exchanged per minute and measure the leak effect in only 8 seconds. Other systems might only be able to test at this level if you get the wearer to actually breathe at this high rate continuously for several minutes. Doing so with other systems would create great stress on the mask wearer!

Yes! Once in a while we see individuals who cannot pass a test because their ear drums are perforated. This is an unusual circumstance, but it does happen. This is usually evident by a traceline that moves up and down throughout the test.

First, verify that the subject is actually holding his breath by closing the airway. Instruct subject to press tongue firmly against and towards the back of the roof of mouth. This will help close the throat completely and assure an airtight seal.

Second, examine the obvious causes for leakage which include facial scars, beard or stubble, exceptionally thin face or indented temples, hairline intercepting the seal of the mask or the mask pulled too tightly producing skin puckering around the seal.

After you have eliminated these as a possibility it is time to consider that the subject may have a perforation in the ear drum that is resulting in a leak to the mask.

If there is a perforation, there would be a clear passage way from the inner ear through the Eustachian tube and into the sinus cavity. A perforation in the ear drum (tympanic membrane) would open the ear to the outside and thus be measured as a leak. A way to confirm this is to have the employee insert tight-fitting ear plugs and perform another fit test. (If ear plugs are not available, the employee could put fingers in their ears to block the possibility of air flow.) Perform another fit test, and if the fit factor passes and is significantly higher, this would suggest leakage through the ear.

A person passing the fit test while wearing ear plugs should also utilize the ear plugs while wearing the mask in a real work environment. An open passageway through the ear can potentially introduce harmful vapors into the sinus cavity and beyond.

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