In most cases, no. Gas detection systems are built with consumable sensor elements that wear out over time. During calibration, we can determine the life of each sensor and advise whether it should be replaced.
Usually, only the sensor element needs replacing — even in older or discontinued systems — unless that specific sensor type is no longer available.
That said, in some situations, maintaining an older unit can cost more than replacing it with a new one. We’ll always review your setup and recommend the most cost-effective and reliable option for your facility.
At a minimum, WorkSafeBC requires gas detection systems to be calibrated once per year. In some environments, more frequent service is necessary:
- Parkades / parking garages → every 6 months
- General occupational health & safety applications → every 12 months
- Manufacturer’s guidelines → always follow the service intervals specified for your specific equipment
Regular calibration ensures that sensors remain accurate, compliant, and effective in protecting workers and the public.
References
Even with regular calibration and maintenance, gas sensor lifespan varies depending on the type of sensor, operating conditions, and exposure levels. Factors such as extreme temperatures or exposure to high concentrations of the target gas can drastically reduce sensor life.
Typical Sensor Life Span
| Sensor Type | Typical Life Span | Notes |
|---|---|---|
| CO (Carbon Monoxide) | 3–6 years | Normal use at temperatures above –10 °C |
| NO₂ (Nitrogen Dioxide) | ~3 years | In air |
| O₂ (Oxygen) | ~2 years | Until readings fall below ~85% of the original 20.9% |
| H₂S (Hydrogen Sulfide) | ~2 years | In air |
| Combustibles | Up to ~5 years | Dependent on gas type and conditions |
| Cl₂ (Chlorine) | ~2 years | In air |
| NH₃ (Ammonia) | ~2 years | In air |
Important: These figures represent typical lifespans. Actual performance will vary depending on the environment, usage, and exposure history. Regular bump tests and full calibrations are the only way to confirm that your sensors remain accurate and reliable.
A bump test is a quick, functional check to confirm that a gas detector’s sensors are working correctly. The detector is briefly exposed to a known test gas, and the readings should respond within about ±10% of the expected value.
Unlike a full calibration, a bump test doesn’t adjust or fine-tune the sensors — it simply verifies that:
- The sensors can detect gas,
- The alarms trigger as expected, and
- The instrument is safe to use in the field.
If the readings fall outside the acceptable range, or if the alarms don’t activate, the device should be removed from service and calibrated or serviced before use.
A full calibration is the complete manufacturer-recommended procedure for ensuring a gas detector is accurate and safe to use.
It typically includes:
- Fresh air calibration to establish a clean baseline, followed by
- Span calibration, where the sensors are exposed to a certified test gas.
The instrument’s electronics then determine whether the sensors pass or fail.
Full calibration goes beyond a bump test or simple adjustment — it’s the most reliable way to verify the detector is functioning properly.
Calibration is the process of exposing a gas detector to a certified test gas and adjusting the unit to ensure its readings are accurate.
This service corrects for natural sensor drift as the detector ages and helps minimize measurement uncertainty. Regular calibration ensures that your gas detection system responds correctly, giving you accurate measurements and maximum safety.
Carbon monoxide (CO) and nitrogen dioxide (NO₂) are two hazardous gases commonly found in vehicle exhaust and poorly ventilated indoor spaces. Both are colorless and odorless, which makes them especially dangerous without proper detection.
- Carbon monoxide (CO) is often called the “Silent Killer”. When inhaled, it binds to hemoglobin in the blood and prevents oxygen from reaching vital organs. Even small amounts can cause headaches, dizziness, nausea, and confusion — and higher exposures can quickly lead to unconsciousness or death.
- Nitrogen dioxide (NO₂) is a toxic byproduct of fuel combustion. It irritates the lungs and airways, and exposure can cause coughing, shortness of breath, chest pain, or more serious respiratory problems, especially for people with asthma or other lung conditions.
Key differences
| Carbon Monoxide (CO) | Nitrogen Dioxide (NO₂) | |
|---|---|---|
| Source | Incomplete combustion of gasoline, propane, wood, or other fuels | Combustion of fossil fuels, especially in vehicle exhaust |
| Properties | Colorless, odorless, flammable gas | Reddish-brown gas with sharp odor (at higher concentrations) |
| Health Effects | Prevents oxygen transport → suffocation, confusion, unconsciousness | Irritates lungs/airways → coughing, chest pain, respiratory distress |
| OSHA PEL | 50 ppm | 5 ppm |
| NIOSH REL | 35 ppm | 1 ppm |
Why this matters: Both CO and NO₂ can build up quickly in enclosed vehicle bays, parking garages, and other confined spaces. Detection systems are critical for early warning and compliance with safety regulations.
Calibration gases are essential for ensuring your gas detection equipment is accurate and reliable. They fall into two main categories, each with different handling and shelf life requirements.
Reactive vs. Non-Reactive Gases
- Reactive gases (e.g., ammonia, chlorine, hydrogen sulfide, sulfur dioxide, hydrogen chloride, hydrogen cyanide)
- Less stable; may react with oxygen, moisture, or cylinder materials
- Stored in aluminum cylinders with treated stainless steel valves
- Shorter shelf life: 6–12 months
- Non-reactive gases (e.g., methane, propane, hexane, isobutylene, nitrogen, hydrogen, carbon monoxide, carbon dioxide)
- Chemically stable under most conditions
- Stored in steel cylinders
- Longer shelf life: ~3 years
Factors That Affect Shelf Life
- Gas concentration
- Higher concentrations of reactive gases often last longer than low concentrations, since small reactions have less overall effect.
- Cylinder quality
- Smooth interior walls reduce the surface area for reactions.
- High-quality valves and materials further extend shelf life.
- Cylinder size
- Larger, high-pressure cylinders last longer, as the gas-to-surface ratio is lower.
Safety and Best Practices
- Never use a cylinder that lacks clear identification of its contents.
- Always check the expiry date before use.
- Using expired or inappropriate calibration gas can result in improper calibration — creating a false sense of security and potentially dangerous conditions.
Gas detection sensors naturally drift away from their original settings over time as they age and are exposed to gases. Without calibration, the readings may become unreliable — which creates a potential health and safety risk.
All manufacturers require regular calibration in their product manuals. In addition, WorkSafeBC requires gas detection systems to be serviced at least once a year, or more often if recommended by the manufacturer.
Choosing CMJ Equipment means you’re getting more than a routine calibration — you’re getting a certified, reliable partner focused on safety, compliance, and cost control.
Certified Expertise
- Authorized service provider for many major manufacturers — a certification most competitors cannot provide.
- Every calibration uses fresh, certified test gas (never stale-dated).
Comprehensive Service
- Detailed service reports after each visit for your compliance records.
- Testing of connected exhaust systems (when integrated with your gas detection unit).
- Backed by our parent company SECURCO, allowing integration with other life-safety systems.
Convenience & Savings
- Recurring service agreements with firm pricing for 3 years, so no surprises.
- Trade-in program available to help reduce long-term maintenance costs.
With CMJ Equipment, you can be confident your gas detection system is serviced to the highest standards — keeping your people safe, your facility compliant, and your costs predictable.
While residential gas detectors are much cheaper, they are not designed or certified for the demands of commercial or industrial environments. Using the wrong type of detector can be unsafe, non-compliant, and even unlawful.
Enclosures
- Residential: Lightweight plastic housings, not waterproof, no IP rating, designed to sit on a wall with little to no maintenance. In an industrial space, most would not last a year.
- Commercial: Rugged, waterproof, IP-rated, lockable enclosures designed to withstand heat, cold, dust, water spray, machinery, vehicles, and even vandalism.
Sensors
- Residential: Basic sensor technology, tested at the factory and generally never recalibrated. Readings are intermittent, with simple ON/OFF logic.
- Commercial: Advanced sensor options (electrochemical, infrared, catalytic, etc.), designed for specific gases and conditions. They require regular bump tests and full calibrations for accuracy and continuous safety monitoring.
Functionality & Configurability
- Residential: Maintenance-free, fixed alarm settings, and a delayed “time-weighted” alarm logic (often waiting up to an hour at above-limit exposure before triggering).
- Commercial: Fully configurable, with multiple alarm setpoints (low, mid, high), and can integrate with ventilation systems, building automation, strobes/horns, data logging, remote notifications, and more.
Certification & Compliance
- Residential: Certified for household use under consumer standards (e.g., UL, CSA).
- Commercial: Certified under stricter national and international standards for non-hazardous and hazardous environments. OSHA and NIOSH workplace exposure limits require approved commercial-grade detection systems.
The Bottom Line
Residential and commercial detectors are not interchangeable. Commercial gas detection devices have the ruggedness, accuracy, configurability, and certifications needed to protect workers and facilities. Using the wrong device in the wrong environment risks safety, compliance, and costly liability.
