Stop COVID-19 From Spreading – Isolation Room Safety

Isolation Room Basics

Isolation rooms are controlled, critical environments in hospitals. When patients have communicable diseases like COVID-19, they are normally placed in one of these isolation rooms. Isolation rooms achieve their effectiveness in controlling contagious disease by keeping internal room pressures lower that areas outside of the room, thus keeping all of the ‘bad stuff’ inside the room. It is easy to determine that a room is a negative pressure room by opening the door.  If the door of negative pressure room is opened a rush of air enters the room. This happens because areas of higher pressure (i.e. areas outside of the isolation room) will naturally move to areas of lower pressure (i.e. the isolation room interior).

The function if the room is simple; if air rushes in, when a doctor or nurse enters to treat the affected patient, theoretically no infected air from within the patient room can escape through an open door.

More protection needed

Most hospitals already have some isolation rooms. Recently, however, hospitals have become overwhelmed with cases of COVID-19 (Coronavirus), and they are in need of additional isolation rooms.  This has led to creating temporary isolation rooms to maintain the safety by protecting caregivers, patients, doctors, nurses, and the general public.  Although creating these negative pressure rooms is simple in theory it is sometimes difficult to achieve.

A critical aspect of maintaining correct pressures of an isolation room is the ability to monitor the actual negative pressure differential.  It is not enough to determine whether a room is a negative pressure room by opening the door and feeling the air from the hall flow into the room.  It is crucial to use some form of instrumentation. In years past, many hospitals turned to a device known as a “Ball In The Wall” or a “Ball In Tube” pressure indicator. These simple devices can be easily understood and implemented. They consist of a ball inside of a tube. Theoretically, when there is higher or lower pressure on a side of the tube protruding a wall, the ball “moves” from a direction of lower pressure to higher pressure, providing a visual indication of the pressure.

These work okay for general applications but fall very short when trying to control serious pandemic-scale diseases like COVID-19.

Here are some of the major downfalls of using “Ball In The Wall” pressure indicators for monitoring room pressure in isolation rooms.

  1. There is no way to determine the actual room pressure. Negative-pressure isolation rooms are required to maintain a minimum of  0.01-inch WC negative-pressure differential1 to the adjacent corridor whether or not an anteroom is utilized to keep communicable disease like COVID-19, SARS, H1N1, etc. under control. A simple Ball In Tube cannot display the actual differential air pressure. It can only indicate that there is some pressure differential present.
  2. No advanced alert system. Unlike more sophisticated systems and instruments, a simple ball in the wall can’t warn critical caregivers in advance if pressure in the isolation room is changing, indicate how much it has changed, or when it changed. Additionally, unlike more complete systems, the ball in the wall can’t notify staff by email, SMS, local alarm or other methods if the required pressure is not maintained.
  3. Another shortfall is the inability for a ball in a tube to report historic data conditions; i.e. when the room started gaining pressure, how long and at what tie the pressure was dangerous, etc… It does not log any pressures.

While these may sound optional, they are critically important attributes that any isolation room should have. Ultimately, it is what will help to stop the spread of COVID-19.

Why are Hospitals Still Using Ball In Wall Pressure Indicators?

Interestingly enough, some of the most technologically advanced hospitals are using these antiquated ball in tube systems to monitor pressure in isolation rooms, surgical rooms, and other critical environments.

One theory for their continued use is the simple fact that because everyone else is using it, it does not matter if it is effective, safe, or even functional. As long as it is widely accepted, then no one can be blamed if something goes wrong. Another theory, is that many “isolation rooms” are not actually maintaining negative pressure at the levels specified by overseeing compliance organizations.  This could be a case of “if I don’t know about it, I am not responsible for it.”

It could be said that many hospitals would have to spend a great deal of money to repair faulty equipment and modernize isolation rooms if they were to become aware of the true air pressure in these hospital rooms. When using ball in the wall type pressure indicators, there is a “yes/no” passing grade. Either the ball is visible or it isn’t. The margin for error is huge. The ball may indicate there is in fact some level of negative or positive pressure, but how much? It is near the threshold of leaving the room vulnerable and completely exposed to the public? It could be. Unfortunately, with the ball in the wall – there is no way to know for sure.

Unlike the ball in the wall indicators there are now modern pressure instruments that are calibrated with NIST traceability. This begs the question, “Just how accurate can mass produced ping-pong balls inside a plastic tube be?” Would you trust your patient’s lives or the health and safety of the public on a ball in a tube?

In short, it is a matter of public safety. In many hospitals, a ball in a tube is the only safeguard between a patient infected with a communicable disease like COVID-19 and the health and welfare of the public.

Better solutions

What are hospitals to do? Fortunately, there are many other instruments available which account for all of the holes and gaps in protection the ball in the wall fails to offer. In fact, many of these instruments cost much less and offer considerably more. In a logical world, the answer would be simple, get rid of the outdated and antiquated ball in the wall, and upgrade.

However, deeply ingrained processes and practices must be overcome. Fear of change and technological advance may paralyze the decision making process, even if it is for the betterment of the patient and the public as a whole.

We at Two Dimensional Instruments, LLC are providing hospitals with special pricing and support for our isolation room monitoring instruments through the deadly the COVID-19 outbreak. To learn more about what we can do for your hospital, please contact us or call 877-241-0042


1 Planning and maintaining hospital air isolation rooms
Controlling the spread of infectious diseases is essential to maintaining a safe care environment

Expectations of USP <797> vs cGMPs

ISO requirements for Compounding Sterile Pharmacies (CSP’s)

Expectations of USP <797>

Compounding Personnel

USP <797> F identifies that compounding personnel represent the greatest threat to the safety and efficacy of a CSP, and as such, these personnel must be fully trained prior to preparing any type of CSP. Training should include live/electronic instructional sources (where possible), professional and up-to-date publications in aseptic principles, and demonstration of aseptic skills. Personnel must pass practical and written evaluations (eg, gowning procedures, fingertip testing, air and surface monitoring) and participate in successful semiannual media fills.

Individuals who do not achieve these criteria must be immediately re-instructed and re-evaluated by expert compounding personnel to ensure all deficiencies are corrected. Media fill challenge testing, in which sterile fluid bacterial culture media is transferred via a sterile syringe and needle into a sterile container, is the most practical way to evaluate an individual’s skills in aseptic preparation. F

Air Monitoring

USP <797> states that procedural guidance and practice begins with well-designed and well-constructed facilities, wherein the preparation area (usually ISO 5) F is surrounded by areas of lower classifications, in this case ISO 7, 8, thereby creating a unidirectional airflow from the ISO 5 area (positive pressure) through the ISO 7 area (lower positive pressure area) to the ISO 8 (still lower positive pressure) area to an unclassified area (zero positive pressure, e.g. corridor). A robust sterile operations program must include non-viable, viable, and pressure differential monitoring F. Non-viable monitoring is conducted with particle monitoring devices (a non-continuous monitoring device) and ensures the minimization of particulate contamination. These devices are also referred to as “particle counters.”

Viable particle monitoring should be conducted with active air sampling devices (continuous monitoring device). An environmental sampling planF must be based on a risk assessment of the compounding activities performed. Selected sampling sites must include locations within each ISO Class 5, 7, and 8 area, and the plan should detail the sample locations, methods of collection, sampling frequencies, volume of air sampled, and time of day related to activity in the compounding area. The data must be reviewed and any upward trends investigated to ensure there are no adverse changes within the environment. Additionally, isolation of pathogenic or objectionable microorganisms must be investigated.

(Pic of typical cleanroom layout)

Differential Pressure

Differential pressure monitoring ensures the unidirectional flow of air from high pressure (ISO 5) to lower pressure (ISO 7 and 8) areas. Pressure gauges or velocity meters must be installed and the data reviewed and documented in a log every work shift (or at a minimum, daily). Alternatively, a continuous recording device (i.e. digital data logger and chart recorder – TV2 Cleanroom Monitor) can be used). The pressure difference between the ISO Class 7 and the general pharmacy area must be at least 5 Pascals (Pa) (0.02 inch water column). In facilities where low– and medium-risk level CSPs are prepared, the differential airflow must be maintained at a minimum velocity of 0.2 meters per second (40 feet per minute) between the buffer and ante areas.

Taking into consideration human error and standard risk calculations F, the best solution is using automated chart recorders, and data loggers, to ensure USP requirements for monitoring differential air pressure.

Expectations of USP <797>vs cGMPs


To minimize the potential of microbiological contamination, clean, disinfected surfaces are mandatory and a written cleaning and monitoring programF is required. The current industry standard practice is to use three disinfectants:

  1. Sterile isopropyl alcohol for disinfection of surfaces, instruments, and gloves
  2. A quaternary ammonium or phenolic product for daily and weekly disinfection
  3. A sporicidal agent (eg, accelerated hydrogen peroxide) for monthly disinfection or when microbiological spores are isolated

Surface monitoring will verify the surfaces are within established microbiological limits. A major difference between USP <797> and Current Good Manufacturing Practice regulations enforced by the FDA (cGMPs)F is that the latter requires disinfection qualification studies to demonstrate that disinfectants are efficacious against standard American Type Tissue Collection (ATTC) microorganisms and in-house isolates. Although these studies are expensive, time consuming, laborious, and not required by <797>, FDA may ultimately require they be conducted by a hospital pharmacy.

Both USP <797> and cGMPs require that surface sampling be performed in all ISO classified areas on a periodic basis using contact plates or swabs; <797> requires it be done at the conclusion of compounding. Sample locations must be defined in the EM planF or on a form and should include surface wipe sampling of the working areas in biological safety cabinets (BSCs); compounding aseptic containment isolators (CACIs); counter tops where finished preparations are placed; areas adjacent to BSCs and CACIs, including the floor directly under the work area; and patient administration areas. An investigation must be conducted when trends or pathogens/objectionable microorganisms are found.

Regulatory Divergence Between USP <797> and cGMPsF: The requirements of cGMPs are general and provide an overview of what is necessary for manufacturing facilities to produce safe and efficacious products. Interestingly, <797> sometimes provides more details than cGMPs.

HEPA Filter Leak Test

HEPA filtration, for example, is not mentioned in cGMPs and the only reference to air filtration is in it’s section § 211.46 Ventilation, air filtration, air heating and cooling: (c) Air filtration systems, including prefilters and particulate matter air filters, shall be used when appropriate on air supplies to production areas. If air is recirculated to production areas measures shall be taken to control recirculation of dust from production. In areas where air contamination occurs during production, there shall be adequate exhaust systems or other systems adequate to control contaminants. In contrast, <797> states: All HEPA filters shall be efficiency tested using the most penetrating particle size and shall be leak tested at the factory and then leak tested again in situ after installation.

However, FDA fills this and other cGMP voids by publishing Industry Guidance reportsF. For example, the Aseptic Processing guidance includes a section on HEPA filtration that recommends performing leak testing for each HEPA filter twice a year; USP <797> does not provide a definitive frequency for conducting leak testing. In this instance, FDA may expect a hospital pharmacy to follow cGMPs (the Aseptic Processing guidance) and conduct leak testing twice a year. Considering that HEPA filters produce unidirectional air that contacts surfaces and components used to prepare CSPs, this expectation is not unrealistic and should be adopted by pharmacy to ensure CSPs are not subject to extraneous airborne contaminants.

Pressure Differentials

A similar situation exists with differential pressures. USP <797> includes a section entitled, Pressure Differential Monitoring F that states, A pressure gauge or velocity meter shall be installed to monitor the pressure differential or airflow between the buffer area and the ante-area and between the ante-area and the general environment outside the compounding area. The results must be reviewed and documented on a log at least every work shift (minimum frequency, at least daily) or by a continuous recording device like the TV2 by Two Dimensional Instruments, LLC. The pressure differential between the ISO Class 7 and the general pharmacy area shall not be less than 5 Pa (0.02 inch water column). In facilities where low- and medium-risk level CSPs are prepared, differential airflow shall maintain a minimum velocity of 0.2 meters per second (40 feet per minute) between buffer area and ante-area.

The cGMP Aseptic Processing guidance also includes a section on pressure differentials and mentions the term numerous times. For example, it states that an essential part of contamination prevention is the adequate separation of areas of operation. To maintain air quality, it is important to achieve a proper airflow from areas of higher cleanliness to adjacent, less clean areas. It is vital for rooms of higher air cleanliness to have a substantial positive pressure differential relative to adjacent rooms of lower air cleanliness. For example, a positive pressure differential of at least 10-15 Pascals (Pa) should be maintained between adjacent rooms of differing classification (with doors closed). When doors are open, outward airflow should be sufficient to minimize ingress of air, and it is critical that the time a door can remain ajar be strictly controlled.

Given that cGMP expectations for pressure differentials are more stringent than <797>, it may appear that following cGMPs imposes an unnecessary burden. However, most BSCs and LAFWs are designed to achieve differential pressure and air flows that adhere to cGMP requirements, and a pharmacy simply needs to have these measurements certified twice a year to demonstrate they are compliant with both <797> and cGMPs.

Smoke Testing

USP <797> and cGMPs differ on smoke studies, but the differences are minor. For example, <797> states, In situ air pattern analysis via smoke studies shall be conducted at the critical area to demonstrate unidirectional airflow and sweeping action over and away from the product under dynamic conditions. Whereas, the Aseptic Processing guidance states, Smoke studies and multi-location particle data can provide valuable information when performing qualification studies to assess whether proper particle control dynamics have been achieved throughout the critical area. As neither document provides details related to frequency, compliance to both documents can be achieved by conducting smoke studies during initial installation and after any biannual leak test that does not meet the recertification requirements.


The pressure on hospital pharmacies to ensure compounding operations are compliant is only increasing as regulators, from state boards of pharmacy to accrediting agencies, are inspecting compounding practices and expecting compliance to USP <797> and, in some cases, cGMPs. Even hospital pharmacies that operate as 503A facilities should be cognizant of cGMP requirements. In fact, the close similarities between <797> and cGMPs related to environmental monitoring provide a strong argument for hospital pharmacists to not only educate themselves on both regulations, but also to consider implementing EM practices that achieve the aims set forth in both documents.

Airborne Infection Isolation Rooms (AIIRs) & COVID-19: Ensuring Patient Containment

Airborne Infection Isolation Rooms (AIIRs)

All U.S. hospitals should be prepared for the possible arrival of patients with Coronavirus Disease 2019 (COVID-19). All hospitals should ensure their staff are trained, equipped and capable of practices needed to:

  • Prevent the spread of respiratory diseases; including COVID-19 within the facility
  • Promptly identify and isolate patients with possible COVID-19 and inform the correct facility staff and public health authorities
  • Care for a limited number of patients with confirmed or suspected COVID-19 as part of routine operations
  • Potentially care for a larger number of patients due to an escalating outbreak
  • Monitor and manage any healthcare personnel that might be exposed to COVID-19
  • Communicate effectively within the facility and plan for appropriate external communication related to COVID-19

The following checklist highlights important areas for hospitals to review in preparation for potential arrivals of COVID-19 patients.

__Confirm the number and location of Airborne Infection Isolation Rooms (AIIRs) available in the facility (ideally AIIRs will be available in the emergency department and on inpatient units).

__ Document that each AIIR has been tested and confirmed to be effective (e.g., sufficient air exchanges, negative pressure, exhaust handling) within the last month. The AIIR should be checked for negative pressure before occupancy. If the instrument used to monitor negative pressure provides logging capabilities, it is ideal for healthcare staff to review them to verify the room stability before, during and after infected patient occupancy.

Verify each AIIR meets the following criteria:

__ Minimum of 6 air changes per hour (12 air changes per hour are recommended for new construction or renovation).

__ Air from these rooms should be exhausted directly to the outside or be filtered through a high-efficiency particulate air (HEPA) filter before re-circulation.

__ Room doors should be kept closed except when entering or leaving the room, and entry and exit should be minimized.

__ When occupied by a patient, the AIIR must be checked at least daily for negative pressure.

__ A protocol is established, which specifies that aerosol-generating procedures that are likely to induce coughing (e.g., sputum induction, open suctioning of airways) are to be performed in an AIIR using appropriate PPE.

__ Facility has plans to minimize the number of HCP who enter the room. Only essential personnel enter the AIIR. Facilities should consider caring for these patients with dedicated HCP to minimize risk of transmission and exposure to other patients and HCP.

__ Facility has a process (e.g., a log, electronic tracking, dual-purpose data logger and room pressure variable monitor) for documenting HCP entering and exiting the patient room.

__ Facility has policies for dedicating noncritical patient-care equipment to the patient.

__ Patient movement outside of the AIIR will be limited to medically-essential purposes

__ Patients transported outside of their AIIR will be asked to wear a facemask and be covered with a clean sheet during transport.

Airborne Isolation Room Specifications as per CDC

This is a single patient room equipped with special air handling (able to maintain negative pressure) and ventilation capacity. The negative pressure room is also known as an Airborne Isolation Room. This negative pressure room is usually a single-occupancy patient-care room frequently used to isolated individuals with confirmed or suspected airborne infection.

Elements of an Airborne Isolation Room 

  • Negative pressure ventilation that creates inward directional airflow from corners of the room. Ideally, this room is prefaced by an anteroom (see below)
  • The airborne isolation room should have a toilet and sink for the patient, and a designated hand washing sink for healthcare workers.
  • Have monitoring equipment including alarms; ideally an instrument capable of providing real-time feedback, current room pressure values, and alerts/alarms if pressures become unstable/unsafe. 
  • Transmit exhaust of air from the hospital room to the outside of the building
  • Recirculate air through a HEPA filter if not expelled to the outside before being returned to the general circulation
  • The door to the room must be kept closed to maintain negative pressure even if the patient is not in the room.
  • The windows in the room should remain closed at all times; opening the window may cause the reversal of airflow, which counters the benefits of a negative pressure room.
  • All healthcare providers who enter the isolated negative pressure room must be fit tested for an N95 respirator, and should take notice of room pressure to ensure that they are within acceptable ranges.
  • Only healthcare providers immunized to the organism in question should enter a room where airborne precautions are in place for varicella or measles or varicella. A respirator is not necessary for immunized individuals but is required for non-immunized workers who provide care.
  • The negative pressure room should have dedicated personal hygiene facilities including a toilet and bathing facilities.
  • One should also have a point of care evaluation for every patient interaction so that one can determine the need for additional precautions.

What is an Anteroom?

This is relatively clean and frequently used area to transition patients/healthcare workers in and out of the airborne isolation room when it is under negative pressure. An anteroom is frequently used as a transitional space between the airborne isolation room and the hallway. It is in this transition area where healthcare workers store their PPE and put on their PPE before entering the airborne isolation room. Ideally, an instrument or monitoring device will display differential pressure values between the anteroom and the Airborne Isolation Room (AIIR) as well as between the anteroom and the hallway.

  1. The laundry hamper is usually located inside the patient room.
  2. The HCP sink is usually in the anteroom location.
  3. The only items that are stored in the anteroom are the procedure or surgical masks, N95 respirator, eye protection devices, gloves, and gowns.
  4. At the hand washing sink, an alcohol-based hand sanitizer and disinfectant wipes should be available.
  5. Posters showing how to perform hand washing must be placed at the sink.

Additional Precautions – Performing Aerosol-Generating Procedures (AGPs)

  • Some procedures performed on patient with known or suspected COVID-19 could generate infectious aerosols. In particular, procedures that are likely to induce coughing (e.g., sputum induction, open suctioning of airways) should be performed cautiously and avoided if possible.
  • If performed, the following should occur:
    • HCP in the isolation room should wear an N95 or higher-level respirator, eye protection, gloves, and a gown, and ensure negative pressure is being maintained at all times via a visual indicator displaying negative pressure values.
    • The number of HCP present during the procedure should be limited to only those essential for patient care and procedure support. Visitors should not be present for the procedure.
    • AGPs should ideally take place in an AIIR.
    • Clean and disinfect procedure room surfaces promptly as described in the section on environmental infection control below.

Cautionary Statement

In most hospital Airborne Isolation Room (AIIRs), negative pressure monitoring is accomplished through antiquated and non-specific gauges like the ball in tube (Ball In The Wall), or Magnehelic gauges. These gauges offer the most basic in isolation room pressure monitoring. Caregivers relying on these antiquated instruments will not know exact pressures, have the option to monitor both negative and positive pressure differentials, receive alerts in advance when pressure levels become unsafe, no ability to view logged data, no ability to chart data, etc.

More technologically advanced instruments such as the TV2 Room pressure monitor provide patients, staff and the general public with a more comprehensive barrier of protection via an advanced alert system, visual alarms and the access to stored data points for detailed room values 24/7. With pandemics like COVID-19, patient and public safety should not be left up to chance; relying on outdated hospital equipment like a ping pong ball in a plastic tube. View a comparison between ball in the wall type instruments and more advanced, complete solutions. 

Operating room

“Ball In The Wall” Not Effective For COVID-19 Control

Controlling COVID-19: Hospitals

Very basic and antiquated devices such as the “Ball In The Wall” negative room pressure monitors are highly ineffective compared to the TV2 in preventing cross-contamination from infectious disease such as COVID-19 (Coronavirus). 

Hospitals have a monumental challenge ahead in light of the world-wide outbreak of the contagious COVID-19, otherwise known as “Coronavirus.” Now more than ever, hospitals are designing and preparing controlled environments with specialized air filtration systems (HVAC) and instrumentation to monitor differential room air pressure to reduce the possibility of cross-contamination from patients who test positive for COVID-19, or may show early symptoms of this deadly flu virus.

As with any infectious disease, hospitals typically quarantine patients in negative air pressure isolation rooms, or simply “negative pressure rooms.” This means air outside the patient’s room is maintained at a higher pressure than the air inside the patient’s room. Basically, when the patient’s door is opened by hospital staff the air will “rush” into the room, thereby preventing infected air from inside the patient’s room from escaping into the hall or adjacent room. CONTROLLING THE SPREAD OF THIS DISEASE IS VERY DEPENDENT ON THIS PROCESS WORKING AS IT SHOULD.

The anatomy of a negative pressure isolation room can be very basic, or very complex. All negative pressure rooms, however, require instrumentation to monitor negative room pressure. The go-to for many decades has been the “Ball In The Wall” which basically is a plastic tube which contains a Styrofoam ball inside. It has a small vent on either end, and passes through a wall between the controlled space (negative pressure area) and the positive pressure area.  Depending on the pressure levels, the ball will move forward or backward as pressure levels increase or decrease. About 60 years ago, this was a sufficient solution, because it was the ONLY solution.

These “ball-in-the-wall” devices are not only very inaccurate, but do not provide ample notification when and if a controlled environment becomes compromised. In essence, this means if a negative pressure room becomes compromised because of an air lock leak, HVAC issue, electrical problem, etc – then every single patient, and all staff in the hospital are at risk of contamination.

Alternatives Are Mandatory

Technology is accelerating at an incredible rate. No one knows this better than the healthcare industry; they usually take full advantage of technological advancements in order to provide more comprehensive patient care and safety. But using the ball in the wall is an exception to this rule. Some hospitals and treatment centers are still relying on age-old devices like the ball in the wall to prevent the spread of infectious disease. A tube containing a Styrofoam ball is in no way precise enough to provide protection against the spread of disease; especially if on one side of that wall there is a patient with a communicable disease or virus like COVID-19.

One such alternative would be to integrate stand-alone digital differential room pressure monitoring instruments. Ideally, these devices would be able to immediately and simultaneously alert staff, facilities managers and caregivers if conditions inside an isolation room become critical. Local alarms (in-the-room high decibel alarms), immediate automated emails sent to staff, and SMS messages sent to caregivers would help to provide immediate quarantine protocols. With ball in the wall type devices, if no one is looking directly at it – they have no way of knowing if there is an issue. In the case of potential contamination, every millisecond counts.

As technology advances, costs decrease. What may have once been a barrier for adoption due to cost, is now no longer an issue. In fact, there are many products on the market which provide a high level of advanced warning and monitoring for patient isolation rooms, and are cost equilivant to ball-in-the-wall type products.


The CDC is warning all healthcare facilities to immediately revise protective policies and procedures to prepare for what is expected to become a wide-scale pandemic. A great start for healthcare providers on the road to ensuring public safety would be to take inventory of any and all controlled environments, isolation rooms, cleanrooms, etc… and note which of those controlled spaces are relying on ball in the wall type of room pressure indicators.

We at Two Dimensional Instruments have created a comparison showing features of a completely digital-based early warning monitoring system for room pressure as compared to a ball in the wall type of monitor. In this comparison, a “TV2 Cleanroom Monitor (TV-202)” was compared to the “Ball-In-The-Wall” brand of ball-type room pressure indicators/monitors.

All other features aside, perhaps the most important point of differentiation between the TV2 and the Ball In The Wall is the ability to not only receive advanced email/SMS alerts when conditions are unfavorable, but also the ability to log, chart and store all data points. This means you’ll never have to guess what the status of the room is/was at a given point in time. The TV2 Room pressure indicator can store over 80,000 data points (about 2 years worth if logging every 10 minutes) and can be exported in excel format.

Call us today to see why the TV2 Room pressure Monitor is the best pressure indicator for your hospital.

Call now: 877-241-0042