By TEBAOFLEX Jyen. Originally published on May 18, 2026.
What each technology reports
A common non-resettable digital linear heat detector uses two conductors separated by heat-sensitive insulation. At its rated activation condition, the insulation allows electrical contact and the associated controller reports an alarm. The activated section requires repair or replacement under the manufacturer instructions.
Fiber DTS uses an optical interrogator to derive a temperature profile along its sensing path. A fire detection system can evaluate temperature and rate-of-rise criteria in defined zones. An ordinary temperature-monitoring installation is not automatically an approved fire alarm system.
Use the correct detector standard
EN 54-22 addresses resettable line-type heat detectors, including systems with optical fiber, pneumatic tube or electrical sensor cable. EN 54-28 addresses non-resettable line-type heat detectors. The distinction is not simply optical versus copper.
Check the approval or certification of the complete sensing element, controller, interfaces and configuration for the intended application. A test on a cable sheath or a generic EN 54 reference does not establish approved detector spacing, tunnel coverage or conveyor performance.
Location and response require separate verification
Some digital systems provide only an alarm zone; compatible locator electronics may estimate distance to an activated location. The calculation depends on the specified conductor resistance, lead cable, connections, calibration and circuit topology. Do not assume every digital cable locates a fire to one metre.
For DTS, sampling interval, spatial resolution, temperature accuracy and scan time are different quantities. A display showing one-metre samples does not prove one-metre hot-spot resolution. Temperature averaging over a sensing length can reduce the apparent temperature of a small hot object.
Installation and hazardous areas
Set routing, spacing, fixing and maximum normal ambient temperature from the approved design. Physical protection must not prevent the required heat transfer. Verify response under representative airflow and geometry rather than applying a liquid-bath time constant to an open conveyor.
A passive sensing cable is not automatically approved for every hazardous area. Electrical detector circuits need the specified interface and protection assessment; optical systems also need applicable installation and ignition-risk evaluation. Follow the relevant equipment certification and control drawings.
Compare lifecycle cost on the actual route
Compare controller channels, sensing length, lead-ins, installation, approvals, spares, commissioning and repair access. A universal kilometre break-even point or an invented cable price is not a sound basis for selecting a fire protection system.
Resettable means that the system can resume operation after conditions return to normal within its limits. Fire-damaged optical cable, coatings, connectors or supports may still require replacement. Document post-event inspection, functional tests and who is authorized to restore protection.
Primary references and specification evidence
The references explain the cited technology or manufacturer example. They are not TEBAOFLEX product approvals or evidence that a supplied batch has passed the tests. Request the exact product drawing, specification edition, acceptance criteria and traceable records.
Discuss your application
Discuss the duty, installation and required documentary evidence with TEBAOFLEX. WhatsApp: +86 185 9591 3361. Product suitability and test obligations must be confirmed for the specific order.