Securiton ASD 531/532/535

Basic design and function of an aspirating smoke detector

An ASD consists of one or two independent sampling tubes with sampling apertures, and with a highly sensitive smoke sensor in each case. Airflow monitoring ensures that the sampling tubes are constantly checked for pipe breakage and the sampling apertures monitored for soiling. A high-performance fan draws in air from the room or facility being monitored through the sampling tube into the evaluation unit. There the air is continuously evaluated by the smoke sensors. The display and control panel of the evaluation unit indicates the smoke concentration of the sampled air, as well as other alarm, fault and status messages.

Any increase in smoke concentration levels is detected very early on. Pre-signals and one or two main alarms can be programmed, and signalled via potential-free relay contacts.

Overview of range

The SecuriRAS ASD range consists of three types:

• The ASD 531 detector is tailor-made for small monitoring areas and for customers who would like a device that is easy to use but still want an extensive range of accessories.
• The ASD 532 is the single-channel device for medium-sized monitoring areas. It has the same technical specifications as the ASD 535, but with just one sampling tube and a more compact fan. Configuration, programming, maintenance and networking of the system are the same as for the ASD 535 and just as simple.

• The ASD 535 in 4 versions (1 or 2 channels, with or without smoke level indicator) is the universal device with outstanding performance characteristics for medium-sized and large monitoring areas. Its ambient temperature range reaches as low as -30°C, making it perfect for deep-freeze warehouses.

Highly sensitive smoke sensor

The SSD 53x smoke sensor was specially developed for the SecuriRAS ASD and is the result of comprehensive research. A high-power LED combined with an LVSC (large-volume smoke chamber) sampling chamber results in unparalleled adjustable sensitivity with low aerodynamic resistance and the utmost resistance to soiling. These features ensure long system service life and durability. The patented lint filter helps suppress one-off disturbances.

PC tools for configuration and for calculating the sampling tube

Sampling tubes for all systems can be accurately calculated, optimised and documented with the VdS-tested ASD PipeFlow PC program. This offers the possibility of asymmetrical and therefore cheaper pipe layouts.

ASD Config is the tool for commissioning and maintaining the ASD 532 and 535. The «Config over Line» function means this can be used without additional networking, including from the fire alarm control panel (FACP). Plus RS 485 networking allows an entire ASD array (ASD 535 and 532) to be visualised and operated at the same time.

Commissioning

The ASD 532 and 535 can also be commissioned with «Easy Config», without a PC. With this method, practically the same functions are available as with the ASD Config PC tool. The ASD 531 also uses a simplified process known as «BasiConfig». This allows somebody to commission an ASD 531 with almost no training. All that is needed is the response grade required, and then it is a case of setting the number of sampling apertures and calibrating airflow measurement. Everything else is taken care of by the detector itself.