Laboratories
There are many types of laboratories including, without limitation, diagnostic, research, and industrial labs. Each type of laboratory has different safety requirements based on its particular specialty in various science, medicine, and industry segments. Depending upon the lab specialty, hazardous materials such as poisons, infectious materials, radioactive elements, and/or compressed gases may be present.
Compressed gases, most commonly argon, nitrogen, and oxygen, are widely used in laboratories. For instance, liquid nitrogen may be used in a diagnostic lab to preserve specimen samples by freezing them with nitrogen’s extreme cold temperature. While compressed gases are safe when properly used and stored, improper handling or usage can cause a leak, which could be hazardous to laboratory personnel and possibly cause an explosion.
A gas leak may occur if a gas cylinder is improperly stored or a tank becomes damaged in transit. Gas cylinders are pressurized, so improper handling could cause them to dent, making them more susceptible to explosion.
PureAire oxygen monitors constantly check the levels of oxygen in the air, and in the event of a gas leak and a drop in oxygen to unsafe levels, PureAire’s monitors will activate audible and visual alarms to alert lab personnel. Since oxygen, nitrogen, and argon are colorless and odorless, there would be no way to detect a leak absent proper oxygen monitoring. Laboratory safety best practices call for oxygen monitors to be installed anywhere there is a risk of gas leaks. The oxygen monitors should be placed wherever compressed gases are stored, and in all rooms where the gas is used. For more information on laboratory safety — NIH -Protocol for Use and Maintenance of Oxygen Monitoring Devices 2021.
PureAire’s oxygen monitors continuously measure oxygen, requiring no time-consuming maintenance or calibration. Each PureAire O2 monitor has an easy-to-read screen that displays current oxygen levels for at-a-glance readings by laboratory employees, who derive peace of mind from the monitor’s presence and reliability.
Oxygen deprivation is a silent killer. Oxygen-depleting gases, such as nitrogen, argon, and helium, are odorless and colorless, making leaks impossible to detect, unless appropriate monitoring is in place.
PureAire oxygen deficiency monitors can be used to monitor nitrogen, argon, and helium. Carbon dioxide can also be monitored with PureAire’s dual oxygen/carbon dioxide monitor.
PureAire uses a proprietary, non-depleting, zirconium oxide sensor that will last up to 10 years in a normal environment without needing to be replaced.
PureAire’s sensors do not operate under partial pressure, meaning that a PureAire sensor will not need to be adjusted to account for different elevations. Additionally, the sensors will not drift due to changes in barometric pressure.
In contrast, other gas detection companies use depleting, electrochemical sensors. These sensors, because they are depleting, operate for 1-2 years before needing to be replaced. Electrochemical sensors do not offer long-term solutions to companies committed to safety.
PureAire sensors are built to last 10 years. Often, the sensors work much longer. In fact, some of our first customers who started using PureAire products in 1997 report that the sensors are still in operation today.
On the other hand, an oxygen monitor that uses a depleting, electrochemical sensor is like a battery in that, as the sensor depletes, it begins to lose its power and responsiveness. In order to operate accurately, electrochemical sensors must be calibrated frequently.
PureAire sensors are made of non-depleting zirconium oxide, and calibration is typically not required.
However, a visual check of the monitor should be done once a year to verify that the sensor is functioning properly, and span adjustments should be done, as necessary. The sensor requires periodic testing with nitrogen to verify the sensor’s response to low oxygen levels.
In contrast, electrochemical sensors, because they deplete over time, will need to be calibrated every 2-3 months and totally replaced every 1-2 years.
Switching to a PureAire non-depleting, zirconium oxide sensor will save you time and money, while ensuring the safety of your workers and facility.
Electrochemical sensors offered by other gas detection companies lose accuracy over time and must be calibrated. Calibration recharges and resets the monitor to get an accurate reading. It is important to note that an electrochemical sensor can only be calibrated a finite number of times before it must be discarded.
PureAire’s non-depleting zirconium oxide sensor will not experience drift. Oxygen sensors from PureAire will provide long-lasting, reliable, and accurate monitoring for an average of10+ years.
The oxygen monitor covers an area of approximately 692 square feet when mounted on a wall and should be placed no more than 21 feet from potential leak sources such as gas lines, gas cylinders, or any areas where a gas leak might be expected to occur.
To ensure safety, the maximum distance between two monitors mounted to the same wall, should not exceed 30 feet. However, since cryogenic gases, such as argon, helium, and nitrogen, are unpredictable, we encourage you to contact PureAire for additional guidance specific to your needs.
In most circumstances, PureAire recommends that oxygen monitors be installed 3-5 feet away from gas cylinders or cryogenic gas lines. To enable employees to see the monitor display and verify its performance, PureAire recommends mounting an oxygen monitor 3-5 feet off the ground.
There are other options for mounting an oxygen monitor. For instance, PureAire sensors can sample the air from up to 100 feet away, or be installed within a glovebox, freezer, sealed chamber, or even underground. PureAire monitors can also work in environments that require KF-25 flanges, as well as in nitrogen/argon enriched environments.
PureAire’s Sample Draw Monitors pull a sample flow at a rate of 250 ccs per minute. We recommend using 1/4” OD x 3/16” ID polypropylene sample tubing. Using this internal tubing dimension, to calculate transport (response) time, add 2 seconds per foot of sample tubing. For example, if the sample tube is 10 feet long, the initial response time would be 20 seconds (10ft x 2seconds=20seconds) at 15 feet the response time would be 30 seconds (15ft x 2seconds=30seconds), etc.
The response time when using the entire 100 feet of sample tube will take 3.5 minutes (100ft x 2seconds=200seconds or 3.5minutes) for the sample to reach the monitor.
A CO₂ gas detector continuously measures carbon dioxide levels in the air to prevent dangerous exposure. Elevated CO₂ levels can cause dizziness, suffocation, or even death. Carbon dioxide monitors alert personnel before levels reach hazardous concentrations.
Carbon dioxide is colorless and odorless, so leaks or accumulation are not detectable by human senses. Detectors protect people and property in areas like laboratories, breweries, greenhouses, food storage facilities, and CO₂ fire suppression systems.
- NDIR (Non-Dispersive Infrared): Most common; highly accurate, stable, and low maintenance. PureAire’s Carbon Dioxide Monitor includes an NDIR sensor cell to measure CO2 levels reliably. The Monitor will remain accurate over a wide range of temperature (0-50°Celsius) and humidity (0-95%RH) levels. PureAire’s Carbon Dioxide Monitor needs no maintenance or calibration once installed.
- Electrochemical: Sometimes used for low-range monitoring, but less common for CO₂.
- Food and beverage industry (breweries, wineries, bottling plants, bars, and restaurants).
- Food processing and frozen food production facilities.
- Laboratories, universities, pharmaceutical manufacturing, agricultural locations, schools, and office buildings.
The specific application will determine where best to install a PureAire CO2 Monitor. For example, bars and restaurants serving carbonated beverages should install a Monitor 12-18 inches off the floor in areas where compressed CO2 is stored or used.
For applications that require high concentrations of CO2, such as inside greenhouses and grow rooms, the Monitor may be mounted inside the room, with employees utilizing a remote display located on the outside for at-a-glance visibility.
To ensure safety, PureAire generally recommends installing one Monitor for approximately every 400 square feet of your facility’s space. However, since airflow can be unpredictable, we encourage you to contact PureAire for additional guidance specific to your needs.
- 400–1,000 ppm: Normal indoor air; safe.
- 1,000–5,000 ppm: May cause drowsiness or mild discomfort.
- Above 5,000 ppm: Hazardous over long-term exposure; OSHA limit for 8-hour exposure is 5,000 ppm.
- Above 40,000 ppm (4%): Life-threatening; immediate evacuation needed.
Unlike other carbon dioxide monitors, PureAire’s CO2 Monitor does not require quarterly calibration. On a weekly basis, the Monitor recalibrates itself to the ambient CO2 level for reliable performance. The Monitor requires no adjustments or monthly maintenance after installation, providing truly maintenance-free carbon dioxide monitoring.
Yes. PureAire’s CO₂ Detectors have relay outputs for local alarms, ventilation controls, or integration with fire panels and building automation systems. Remote monitoring, such as PureAire’s Remote Digital Display, Horn/Strobes, or CloudConnect, provides real-time alerts, logging, and compliance support.
- Clean dust or debris from the sensor housing.
- Replace sensors at the manufacturer-recommended intervals (typically 5–10 years for NDIR sensors).
Yes. Properly installed PureAire CO₂ Detectors meet International Fire Code (IFC) requirements for CO₂ storage or fire suppression systems, OSHA limits, and other local safety standards.
PureAire Carbon Dioxide Detectors will:
- Activate visual and audible alarms.
- Automatically turn on ventilation systems to reduce CO₂ levels.
- Send notifications via PureAire’s Remote Digital Display or CloudConnect, which can alert building personnel or monitoring centers.
A combustible gas detector continuously monitors the air for flammable gases like methane, propane, or hydrogen. It alerts you before concentrations reach explosive levels, protecting workers, property, and compliance with fire codes.
Depending on the sensor type, detectors measure gases such as methane, propane, butane, hydrogen, ethylene, and other hydrocarbons.
Combustible gases become dangerous when they mix with air in certain concentrations. These are called explosive limits:
- Lower Explosive Limit (LEL): The lowest concentration of a gas in air that can ignite if exposed to an ignition source. Below the LEL, the mixture is too “lean” to burn.
- Upper Explosive Limit (UEL): The highest concentration of a gas in air that can ignite. Above the UEL, the mixture is too “rich” to burn.
- LEL: Percentage of gas concentration at which ignition becomes possible. Combustible detectors typically measure 0–100% LEL.
- PPM (parts per million): A finer measurement, usually used for toxic gases rather than combustibles.
- Molecular Property Spectrometer (MPS): Multi-gas, long life, low maintenance. MPS sensors use advanced spectroscopy to analyze the molecular properties of gases in real time, distinguishing multiple gases with one sensor and without requiring frequent calibration.
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- Detects multiple flammable gases with one sensor.
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- Long lifespan of 15+ years, with minimal calibration required.
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- Resistant to poisoning or drift.
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- Works across wide temperature and humidity ranges.
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- Applications: Oil & gas, industrial plants, labs, battery charging areas, and environments with unknown or mixed flammable gases.
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- Detection limits: Typically, down to 0–100% LEL.
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- Gases detected: Hydrogen, methane, propane, butane, ethylene, ethane, and more (14+ common hydrocarbons).
- Electrochemical Sensors: Gas molecules react with an electrolyte inside the sensor, producing an electrical signal proportional to gas concentration.
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- High sensitivity and selectivity.
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- Compact and cost-effective.
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- Low power consumption.
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- Limited lifespan (2–3 years).
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- It can be cross-sensitive to other gases.
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- Environmental conditions (humidity, temp) affect performance.
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- Applications: Toxic gas monitoring (CO, H₂S, NO₂, Cl₂, O₂ deficiency/enrichment). Widely used in confined space entry, labs, and industrial facilities.
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- Detection limits: Parts per million (ppm) — varies by gas.
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- Gases detected: Carbon monoxide, hydrogen sulfide, nitrogen dioxide, chlorine, oxygen, ammonia, and other toxic gases.
- Pellistor (Catalytic Bead): Low-cost but requires oxygen and regular calibration. Detects flammable gases by oxidizing them on a heated catalyst bead, causing a temperature change and resistance shift.
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- Proven, low-cost technology.
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- Effective for a wide range of flammable gases.
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- Fast response.
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- Lifespan 2–5 years.
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- Applications: Flammable gas monitoring in oil & gas, refineries, chemical plants, and confined spaces.
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- Detection limits: Typically 0–100% LEL.
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- Gases detected: Methane, propane, butane, hydrogen, and other combustibles.
- Non-Dispersive Infrared (NDIR): Stable and durable, best for methane and CO₂, but cannot detect hydrogen. Infrared light passes through a gas sample; target gases absorb specific wavelengths, allowing concentration measurement.
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- Very stable, long life (5-10 years).
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- Low maintenance, no consumable parts.
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- Highly selective (specific gases absorb specific IR wavelengths).
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- Not effective for gases that don’t absorb IR (e.g., hydrogen).
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- Performance can be affected by dust/moisture.
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- Applications: CO₂ monitoring (greenhouses, breweries, labs, cryogenics), refrigerant leak detection, combustion safety.
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- Detection limits: ppm to % volume, depending on gas.
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- Gases detected: Carbon dioxide, methane, refrigerants, and hydrocarbons that absorb IR.
- Photoionization (PID): Uses UV light to ionize volatile organic compounds (VOCs) and some toxic gases, producing a measurable current.
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- Extremely sensitive (ppb to ppm).
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- Detects a wide range of VOCs.
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- Fast response.
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- Requires frequent maintenance and calibration.
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- Can’t identify specific compounds – measures total VOCs.
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- Humidity can affect readings.
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- Applications: Environmental monitoring, hazmat response, industrial hygiene, and leak detection of solvents and VOCs.
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- Detection limits: Parts per billion (ppb) to parts per million (ppm).
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- Gases detected: Benzene, toluene, xylene, formaldehyde, and thousands of VOCs.
Install detectors near potential leak sources and where gases may accumulate. For lighter-than-air gases (e.g., hydrogen, methane), place sensors high; for heavier gases (e.g., propane, butane), place them near the floor.
In hazardous locations classified by OSHA or NFPA, explosion-proof or intrinsically safe detectors are required. PureAire offers explosion-proof options to meet these safety standards.
Yes. PureAire Combustible Gas Detectors include relay outputs for local alarms, ventilation activation, or connection to fire panels, SCADA, or remote monitoring systems like CloudConnect.
Yes. PureAire engineers its detectors for use under the International Fire Code (IFC) 916, OSHA requirements, and other industry standards. CloudConnect supports compliance with IFC §916.5 by delivering continuous monitoring, logging, and remote alerting.
- MPS: 15+ years.
- Electrochemical: 2-3 years.
- Pellistor: 2–5 years.
- NDIR: 5–10 years.
- PID: 2-5 years.
Calibration is the process of exposing a gas detector to a known concentration of gas to verify and adjust its accuracy. Over time, sensors can drift due to environmental conditions, sensor aging, or contamination. Calibration ensures the monitor continues to give reliable, accurate readings.
- MPS: Rarely requires calibration; designed for long-term stability.
- Electrochemical: Every 6–12 months.
- Pellistor: Every 3–6 months due to poisoning and drift risks.
- NDIR: Usually once a year, sometimes less frequently.
- PID: Often monthly or quarterly, depending on VOC exposure.
Best practice:
- Bump test (a quick exposure to gas to confirm response): Before each use or daily in critical safety applications.
- Full calibration: At the manufacturer’s recommended interval, or sooner if the bump test fails.
Always follow manufacturer recommendations and local safety codes.
A toxic gas detector continuously monitors the air for harmful gases, including carbon monoxide, chlorine, ammonia, and hydrogen sulfide. It warns personnel before levels reach dangerous concentrations. Toxic gas detectors protect workers from low-level poisonous gases (in the ppm range) that can cause immediate or long-term health effects.
The most common include:
• Carbon monoxide (CO) – parking garages, boiler rooms
• Hydrogen sulfide (H₂S) – oil & gas, wastewater treatment
• Chlorine (Cl₂) – water treatment, chemical plants
• Ammonia (NH₃) – refrigeration, food processing
• Nitrogen dioxide (NO₂) – vehicle maintenance facilities
• Sulfur dioxide (SO₂) – power plants, refineries
• Ozone (O₃) – semiconductor, pharmaceutical industries
• Refrigerant gases (classified as A1, A2L, B2L, A3) – HVAC systems, supermarkets, cold storage, data centers
• Electrochemical sensors: Accurate, low-level detection; best for most toxic gases (CO, H₂S, Cl₂, NH₃).
• PID (Photoionization Detectors): Detects volatile organic compounds (VOCs) and low-level hydrocarbons.
• NDIR (Non-Dispersive Infrared): Used more often for CO₂ or gases that absorb infrared light. NDIR sensor cells are highly effective for detecting refrigerant gases across classifications A1, A2L, B2L, and A3.
• CO: 0–100 ppm, 0–1,000 ppm
• H₂S: 0–30 ppm, 0–200 ppm
• Cl₂: 0–1 ppm, 0–3 ppm, 0–10 ppm, 0–50 ppm, 0–200 ppm
• NH₃: 0–75 ppm, 0–100 ppm, 0–200 ppm, 0–300 ppm, 0–1,000 ppm
• NO₂: 0–2 ppm, 0–9 ppm, 0–15 ppm, 0–20 ppm
• SO₂: 0–15 ppm, 0–20 ppm
• O₃: 0–0.3 ppm, 0–1 ppm, 0–3 ppm, 0–300 ppm
• Refrigerant gases (A1, A2L, B2L, A3 classifications): 0–500 ppm, 0–1,000 ppm, 0–5,000 ppm
• Oil & gas: H₂S monitoring in drilling and refining
• Water/wastewater treatment: Chlorine and H₂S detection
• Food & beverage: Ammonia refrigeration monitoring
• Laboratories & pharma: VOC and toxic gas detection
• Manufacturing & automotive: CO and NO₂ monitoring
• Power generation: SO₂ monitoring in flue gas areas
• HVAC, supermarkets, cold storage & data centers: Refrigerant leak monitoring (A1, A2L, B2L, A3 gas classifications)
Consider:
• The specific gas hazards in your facility
• Sensor type (electrochemical, PID, NDIR, etc.) based on gas and concentration range
• Installation environment (indoor, outdoor, temperature/humidity conditions)
• Compliance needs (OSHA, IFC, local codes)
• Integration with alarms, PLCs, or cloud monitoring systems like PureAire’s CloudConnect
• Electrochemical sensors: Every 6–12 months
• PID sensors: Every 3–6 months
Always follow the manufacturer’s recommendation and perform bump tests for safety.
• LEL: Percentage of gas concentration at which ignition becomes possible. Combustible detectors typically measure 0–100% LEL.
• PPM (parts per million): A finer measurement, usually used for toxic gases rather than combustibles.
Yes, in most cases. Some gases, such as hydrogen sulfide (H₂S), carbon monoxide (CO), and ammonia (NH₃), pose toxic risks at very low concentrations (ppm levels) and combustible risks at higher concentrations (% LEL).
• A toxic gas detector is needed to protect worker health by alarming at ppm exposure limits set by OSHA and other agencies.
• A combustible gas detector is needed to prevent explosions or fires when gas levels approach the Lower Explosive Limit (LEL).
Since the alarm thresholds and sensor technologies differ, a single detector usually cannot provide both types of protection. Many facilities use both toxic and combustible gas detectors for full coverage, often integrated into a single safety system. This system can activate building ventilation and advanced warning systems when gas levels reach dangerous concentrations.
If a gas is toxic at low ppm and combustible at higher % LEL, you may need dual detection — one detector set for ppm exposure, another for explosion hazard. Sensor selection depends on whether the primary risk is worker health, explosion, or both.