When it comes to workplace safety in commercial and industrial settings, nothing is more critical than accurate gas monitoring. Gas detector calibration is the cornerstone of ensuring the reliability of your gas detection systems, yet it is often misunderstood or neglected. Calibration ensures your equipment performs as expected, protects lives, and complies with safety regulations.
Why Gas Detector Calibration Matters
Gas detectors are sophisticated instruments that monitor the presence of hazardous gases such as carbon monoxide (CO), hydrogen sulfide (H₂S), methane (CH₄), and many others. These devices can literally save lives—if they work as intended. Over time, environmental factors such as humidity, temperature, and exposure to gas concentrations can affect their sensors. Without proper calibration, a detector may:
- Under-report hazardous levels of toxic or combustible gases
- Fail to trigger alarms, creating potentially dangerous conditions
- Fall out of regulatory compliance, exposing your organization to fines or shutdowns
The stakes are high. That’s why calibration isn’t just a recommendation—it’s an essential safety practice.
Understanding the Calibration Process
Calibration involves testing the sensor’s output against a known concentration of gas (often referred to as a “calibration gas”). The gas detector compares its readings to this known reference and adjusts its internal settings to match.
There are two types of procedures often used:
1. Full Calibration
This adjusts the detector’s response across the entire range of concentrations. It’s more comprehensive and used when the device has shown signs of sensor drift or after major events such as a sensor replacement.
2. Bump Test (or Function Check)
This is a quick verification where the detector is exposed to a known gas concentration for a brief period to ensure it responds correctly. It’s not a substitute for full calibration, but can serve as a routine check. It is also known that electrochemical sensor benefit from periodic bump test and assists in keeping the media active – just like activating the ignition in your car causing the alternator to send a positive charge to the battery thus activating the electrolyte and keeping it active.
When Should You Calibrate Your Gas Detector?
There is no one-size-fits-all answer, but several factors determine the ideal calibration frequency:
● Manufacturer’s Recommendation
Always refer to the manufacturer’s user manual. Most manufacturers suggest calibrating gas detectors every 6 months at a minimum, but high-usage environments may require more frequent intervals.
● Regulatory Requirements
CFC, OSHA, MSHA, NFPA, and other industry-specific regulations may require specific calibration intervals depending on the type of gas and application. Most agencies fall back on the manufacturer’s requirements.
● Operational Environment
Harsh industrial conditions—dust, moisture, and temperature fluctuations—can cause sensors to drift more quickly, necessitating more frequent calibration.
● After Key Events
- If the detector was dropped or exposed to unusually high gas concentrations
- After sensor replacement or maintenance
- Before a critical job or confined space entry
Rule of thumb: Perform a bump test daily or before each use and a full calibration monthly or per the manufacturer’s guidelines.
How to Calibrate a Gas Detector Properly
While many organizations attempt DIY calibration, the safest and most reliable approach is to work with a licensed service provider like MDC Systems, Inc. That said, understanding the calibration process is valuable:
Step 1: Gather Tools and Equipment
You will need:
- The correct calibration gas mixture
- A calibration adapter or cap
- Tubing and a regulator
- A clean, stable environment
- Calibration software (if applicable)
- Voltmeter (if applicable)
- Magnet (if applicable)
Step 2: Zero the Detector
Ensure the unit is in a clean-air environment and zero out the sensor’s baseline readings. This tells the detector what “clean air” looks like before introducing gas. If the background is known to contain gas or other interference chemicals we highly recommend using zero air from a certified gas cylinder to perform the zero calibration.
Step 3: Apply Calibration Gas
Connect the calibration gas and flow it over the sensor for the manufacturer-recommended time (usually 1–2 minutes). Observe the readings to ensure they match the expected value.
Step 4: Adjust the Readings
If the detector’s output doesn’t match the gas concentration, make necessary adjustments via the device’s interface or connected software.
Step 5: Final Verification
Turn off the gas flow and ensure the detector returns to its baseline readings. Store all calibration data for maintenance and safety records and compliance audits.
Can I Calibrate a Gas Detector Myself, or Do I Need a Service?
This is one of the most frequently asked questions—and the answer depends on a few factors:
● In-House Expertise
If your team has the training, equipment, and time to perform calibrations according to manufacturer standards, you can calibrate detectors internally. However, even experienced teams occasionally make mistakes that compromise sensor accuracy.
● Liability and Compliance
A miscalibrated detector could cause significant harm. Regulatory bodies may require third-party documentation or certified calibration. Using an expert service provider ensures calibration is compliant and verifiable.
● Convenience and Accuracy
Professional services like those provided by MDC Systems, Inc. use factory-trained technicians, certified gases, and precision tools. Our calibration includes full documentation, functionality verification, and system integrity checks.
Bottom line: You can calibrate detectors in-house, but professional service offers peace of mind, traceable records, and compliance assurance.
What Gases Are Used for Calibration and Bump Tests?
Calibration and bump tests require traceable gas mixtures tailored to the detector’s specifications. The most common calibration gases include:
● Carbon Monoxide (CO)
Used for detectors in garages, mechanical rooms, and fuel-burning environments.
● Hydrogen Sulfide (H₂S)
Common in wastewater treatment plants, petroleum refineries, and mining.
● Methane (CH₄) and Propane
These combustible gases are calibrated for explosion risk in manufacturing and fuel storage areas.
● Oxygen (O₂)
Although not toxic, monitoring for oxygen-deficient or oxygen-rich environments is critical in confined spaces.
● Nitrogen Dioxide (NO₂), Sulfur Dioxide (SO₂), Ammonia (NH₃), Chlorine (Cl₂)
Often used in chemical processing and industrial refrigeration systems.
Cal gases are supplied in disposable or refillable cylinders and have a shelf life of 6–24 months depending on the gas type.
Common Pitfalls to Avoid in Calibration
Calibration is only effective when done correctly. Here are key mistakes to watch out for:
- Using expired calibration gas: Always check the expiration date.
- Wrong gas concentration: Use the exact concentration required by the manufacturer.
- Skipping the zeroing process: This can offset your readings significantly.
- Not logging calibration data: This is critical for audit trails and compliance.
- Ignoring sensor replacement intervals: Calibration can’t fix a dying sensor.
Professional service providers manage all these factors for you—automating records, using up-to-date tools, and ensuring your system is always in top condition.
Why Choose MDC Systems, Inc. for Your Calibration Needs
At MDC Systems, Inc., gas detection safety is more than a service—it’s a commitment. Based in San Jose, California, and serving clients across the entire United States, we specialize in customized Gas Life Safety Systems (GLSS) for commercial and industrial applications.
What Sets Us Apart
- Over 30 Years of Experience: We’ve delivered safe, cost-effective GLSS solutions since the 1990s.
- Turnkey Solutions: We handle design, I/O logic, SCADA integration, HMI development, and complete installation.
- In-House and Factory-Trained Technicians: Ready with the right gases and tools for every job.
- Tailored Engineering: We understand your operation and tailor systems for optimal performance and regulatory approval.
- Customer-Centric Approach: Free estimates, A+ BBB-accredited, and licensed and bonded professionals.
We know that when it comes to gas safety, you need a partner that’s fast, reliable, and proven. That’s why so many organizations across California and beyond trust MDC Systems with their GLSS needs.
Don’t Guess with Gas—Calibrate It Right
Proper gas detector calibration is not a luxury—it’s a necessity. With evolving environments, aging sensors, and regulatory pressures, ensuring your equipment operates accurately can be the difference between safety and disaster.
Whether you choose to perform your calibrations in-house or seek professional help, the key is consistency, documentation, and proper technique. MDC Systems, Inc. offers the experience, technology, and commitment to keep your people safe and your systems compliant.
Ready to Improve Your Gas Detection Safety?
Partner with MDC Systems, Inc. and experience:
- Accurate and compliant calibrations
- Custom-engineered GLSS tailored to your facility
- Fast, responsive service across California and beyond
- Expert technicians using factory-authorized equipment
Contact us today for a free estimate and discover why we’re the trusted name in gas life safety systems.