Compression test on sprinkler glass ampoules in automatic fire extinguishing systems

Sprinkler glass ampoules are safety-relevant components in automatic fire extinguishing systems. As thermal release elements, they must fail reliably at a precisely defined temperature and activate the extinguishing system. The requirements for development, testing, and quality assurance are correspondingly high.

Test setup and testing technology used

A universal testing machine inspekt table 50 kN is used to test automatic fire extinguishing systems with sprinkler glass ampoules. The system is equipped with the video extensometer ONE1 for non-contact strain measurement and enables precise recording of the mechanical characteristics during the pressure test until the specimen breaks.

Functional principle of the fire extinguishing system with sprinkler glass ampoule

Inside the sprinkler glass ampoule is a hermetically sealed liquid. As the temperature rises, this expands, increasing the internal pressure in the glass body. As soon as the pressure reaches a defined limit value, the ampoule bursts into small fragments and triggers the automatic fire extinguishing system.

Relevant parameters for testing sprinkler glass ampoules

The precise adjustment and monitoring of the following parameters is crucial for the reliable functioning of sprinkler systems:

• Ultimate tensile load or resulting compressive stress
• Elongation of the glass ampoule at the moment of breakage

These parameters provide important information on the reproducibility, functional reliability, and service life of the trigger elements.

Optical strain measurement with video extensometer

Strain measurement is performed contact-free with the ONE1 video extensometer. Even with transparent glass ampoules, the system delivers stable, high-resolution measurement results up to sample breakage thanks to backlighting. This allows even highly dynamic breakage processes to be analyzed reliably.

Conclusion

The combination of the inspekt table 50 kN universal testing machine and optical measurement technology offers a powerful and precise solution for pressure testing sprinkler glass ampoules in automatic fire extinguishing systems. It supports manufacturers and testing laboratories in reproducibly recording safety-relevant characteristic values and ensuring the highest quality standards.

Further information available on request