A gas detector has one job: to warn you about something you cannot see, smell reliably, or measure by eye - a build-up of flammable or hazardous gas heading toward a dangerous level. And it has one insidious failure mode: it can lose that ability entirely while its display still looks perfectly healthy. A drifted or dead sensor sits there powered, green, and blind.
That is what makes gas detection different from most fire systems. You cannot judge it by looking at it. It has to be calibrated and tested on a schedule. Here is how, and why.
> Quick answer: Gas and LPG detectors rely on sensors that drift out of calibration and eventually wear out. They must be periodically calibrated - exposed to a certified gas concentration and adjusted to read true - and bump-tested more often in between to confirm they still respond. Sensors have a finite life and need replacement when they can no longer hold accuracy. Without this, a detector can look healthy and no longer react to the gas it was installed to catch.
Why Sensors Drift
Every gas sensor loses accuracy over time. The chemistry and physics that let it detect gas also degrade it, and the environment speeds that up - dust, contaminants, humidity and repeated gas exposure all push a sensor off its calibration.
The consequence is simple and serious: a sensor reading correctly today can read wrongly in a few months. It might fail to alarm when gas is present, or nuisance-alarm when it is not. That is why a detector cannot be trusted indefinitely on the strength of its installation calibration - the accuracy has to be restored on a schedule. This is the backbone of how we maintain LPG and gas systems.
Bump Test vs Calibration
These two get confused, and the difference matters:
- Bump test - a quick functional check. Apply a known gas, confirm the detector responds and triggers its alarm. It answers one question: does this detector still react to gas? It does not necessarily adjust anything.
- Calibration - the deeper procedure. Expose the sensor to a certified concentration and adjust the detector so its reading matches the true value, correcting accumulated drift.
A good programme uses both: frequent bump tests as a fast confidence check, periodic calibration to actually restore accuracy. One is not a substitute for the other.
Sensors Expire - Track Their Age
Calibration cannot save a sensor forever. Gas sensors have a finite working life and eventually reach a point where they can no longer be brought back to specification. A sensor in a clean environment lasts longer than one exposed to contaminants or repeated high concentrations - but all of them end.
Proper maintenance therefore tracks sensor age and calibration history, so a sensor nearing the end of its life is replaced before it fails - rather than being calibrated over and over until it can no longer hold accuracy and quietly stops protecting the space.
Where Gas Detection Protects
Gas detection is installed wherever a build-up of flammable or hazardous gas is a credible risk:
- Commercial kitchens and restaurants using LPG
- Plant and boiler rooms
- LPG storage and cylinder areas
- Car parks and enclosed spaces where gas could accumulate
- Industrial areas handling combustible or toxic gases
In each, the detector's job is to sense a leak early - before the concentration reaches a dangerous or explosive level - and trigger alarms and, where fitted, shut-off valves and ventilation. In kitchens especially, gas detection often works hand-in-glove with suppression: see how it fits alongside kitchen hood fire suppression as one integrated protection layer.
What "Unmaintained" Actually Means Here
Skipping gas detector maintenance does not produce an obvious broken system - it produces a silent one. The detector drifts, then degrades, and the dangerous end state is a unit that looks powered and healthy on its display but no longer reacts to the gas it was installed to catch. A real leak then develops with no warning until the concentration becomes hazardous.
Because gas is invisible and a leak can reach explosive levels, that silent detector has removed the single early warning the space depended on. There is no beeping fault to prompt action - which is exactly why the calibration schedule cannot be optional.
Put It in the AMC
Gas and LPG detection belongs inside a fire systems AMC alongside the alarm and suppression systems. Bundling it in means detectors are calibrated, bump-tested and life-tracked on a defined schedule with records for inspection - not left as a standalone system that is easy to forget until it fails. Where detection ties into suppression and shut-off, maintaining them under one contract keeps the interconnected protection consistent.
QSERV Technical Services maintains gas and LPG detection across Dubai as a DCD-approved, ISO 9001 contractor with in-house teams - detectors calibrated to certified gas, bump-tested between visits, sensors replaced on schedule, all recorded inspection-ready. Ask us to service your gas detection system before a drifted sensor stops watching.
