Aspirating smoke detector testing proves that smoke at the far end of the pipe network really reaches the detector, and that the alarm really reaches the fire panel. A detector can look healthy on its display and still fail in a real fire if a pipe is cracked or blocked.
In this guide, we explain how to test an aspirating smoke detector in the right order, what to measure and what to write down. Always follow the manual of your own system. Our steps give you the general method that most good tests share.
Why aspirating smoke detector testing is different
A point detector is tested by putting smoke on the detector itself. In contrast, an aspirating system has two jobs. The pipes must carry air to the detector, and the detector must then recognise the smoke. As a result, the test must cover the whole path, not only the sensor.
For this reason, testing is done at commissioning, after any change to the pipes, and then at regular service visits. Read how an aspirating smoke detector works to see why the pipe network matters so much.
Before you start: prepare the system
Good preparation makes aspirating smoke detector testing safer, because it avoids false alarms and wasted time. First, tell the building users and the alarm monitoring centre that a test is planned. Then put the fire panel in test mode, or isolate the outputs that would start extinguishing, door release or fire brigade signals.
- Check that the detector shows no fault and that power is stable.
- Confirm that the filter is clean and the pipes are the ones shown on the design drawing.
- Have the commissioning record ready, so you can compare today’s airflow values with the original ones.
- Use a smoke source approved for fire detector testing. Never use burning paper or a lighter, because soot can contaminate the pipes.
The aspirating smoke detector testing steps
The order below works for most systems, including ModuLaser and MiniLaser.
- Check the airflow. Compare the airflow reading with the commissioning value. A clear drop suggests a blocked hole, a dirty filter or a pipe leak.
- Smoke test the furthest sampling hole. Apply test smoke at the hole that is farthest from the detector, because this is the slowest path.
- Measure the transport time. Time how long the smoke takes to reach the detector. The design must stay inside the limit of the standard, which is 120 seconds under EN 54-20.
- Check the alarm levels. Confirm that the detector moves through its alarm levels and that each level shows on the display.
- Check the panel. Confirm that the alarm and fault signals arrive at the fire alarm panel, for example through the addressable interface card.
- Run a fault test. Block the pipe inlet briefly to create an airflow fault, then confirm that the fault is reported.
Finally, put the system back to normal, reset the panel and tell everyone that the test is over.
What to record after the test
A test without a record is only half a test. Also, write down the date, the engineer, the airflow readings, the transport time for each pipe and the result of every step. In addition, note any change you made to the pipes or the settings.
Good aspirating smoke detector testing leaves a clear paper trail. These notes are valuable next year. If the airflow value slowly drifts, you will see it early and fix it before it becomes a problem.
Common problems found during testing
A short table helps to read the results.
| What you see | Likely cause | What to do |
|---|---|---|
| Low airflow | Dirty filter, blocked hole or pipe leak | Replace the filter, clean the holes and check every pipe joint |
| Transport time too long | Pipe too long or holes badly placed | Review the pipe design with the manufacturer |
| No alarm at the panel | Wrong interface setting or cable fault | Check the relay or address settings and the wiring |
| Alarm comes late | Sensitivity set too low for the risk | Review the alarm levels with the system designer |
Products that make testing easier
The detector and its accessories change how simple a test is. Also, the ModuLaser Standard and Command displays show airflow and alarm levels on site, and the MiniLaser brings the same technology to small rooms. Both use the same replacement dust filter, so one spare part covers both. Read the full range on our aspirating smoke detection page.
Kľúče na prevzatie
- Test the whole path: pipes, detector and panel, not only the sensor.
- Smoke test the furthest sampling hole and measure the transport time against the 120 second limit of EN 54-20.
- Always include an airflow fault test and a check of the signals at the panel.
- Record every reading, so slow changes show up before they become faults.
Často kladené otázky
How often should an aspirating smoke detector be tested?
Test it at commissioning and after any change to the pipes. After that, follow the schedule in your local rules and the maker’s manual, which is usually at least once a year.
Can I test an aspirating smoke detector with a normal smoke spray?
Only with a product approved for testing this type of detector. Some aerosols leave a residue in the pipes, so check the manual first.
What is transport time?
Transport time is how long smoke takes to travel from the sampling hole to the detector. EN 54-20 limits it to 120 seconds.
Do I need a specialist to test the system?
A trained fire alarm engineer should do the test, because the steps also involve the fire panel and the outputs connected to it.
Learn the basics in Aspirating Smoke Detector: How It Works and When to Use One, then read how to keep the system in good shape in our guide on aspirating smoke detector maintenance.