Classification of Release Events

The scanfeld® Profiler – Automated Classification of Gas Detection/Release Events

The scanfeld® from Grandperspective is a specially designed remote monitoring system that offers a high-level classification of different gas leak events. By providing a real-time monitoring approach to gas leaks, the scanfeld can be used to observe large industrial sites using just a few sensor units. Alongside providing early warning detection and real-time monitoring, the scanfeld system can also help with any post-release safety procedures involving third parties (for example, health and safety inspectors or firefighters). So, there are several ways where the scanfeld can help to keep industrial sites safe when chemicals are inadvertently released into the local environment.

While the scanfeld system is very versatile in itself, there are a number of optional modules that can be added to it to enhance the performance of the instrument in certain environments and tailor the capabilities of the instrument to your specific requirements. One of these optional modules is the chemical profiler, which provides a level-based alerting approach when a gas release has been detected.

The Chemical Profiler

The chemical profiler is one of the optional modules available and checks both the amount of gas emitted from a release event and the persistence over time. The chemical profiler is always running in the background and the operator automatically becomes notified about any release events with a levelled alert system—technical emissions (e.g caused by maintenance) or small-scale release events are rated differently to large gas clouds.

Beyond providing an alert about the event, the chemical profiler also gives further insights into the type and severity of the gas leak. One of the other key features is that the profiler provides a validation of the identified compound, and this enables the warnings and alerts to be accurately classified and seen by the user on a browser-based interface. The chemical profiler also provides a validation in time and spatial distribution, and if multiple sensors are used on the site, the profiler can cross-validate single points to ensure the highest degree of accuracy for the correct warning level.

The Different Alert Levels

There are a number of different alert levels generated by the chemical profiler which are based on the severity of the gas release event. Alert level 0 means that there has been no significant detection of a gas, however, once the profiler detects gas in one of the designated scan areas, it triggers an alert which is categorised as either a low (level 1), medium (level 2), or high (level 3) alert level.

For an alert to be triggered by the profiler, the gas must be detected for a prolonged period of time to ensure that it is a real threat. Once the gas has been detected for long enough, the profiler will automatically measure both the type of gas and the column density of the gas by comparing it with gas signatures stored within its database.

The severity of the alert is determined by comparing the concentration of gas against pre-defined threshold levels, and once this threshold is reached, the alert is generated. If the concentration of gas further increases over time and passes a higher pre-determined threshold level, then the alert level will be increased appropriately. On the other hand, if the gas levels go below the pre-determined threat levels, the alert levels are reduced accordingly. The different alert levels also have a designated colour coding based on the severity—yellow for low, orange for medium and red for high—for ease of tracking.

Tracking the Alerts with Profiler

Once the user has been provided with an alert on the user interface, there are a number of functions which are available to the user. In the user interface, coloured alert triangles and alert lists are two ways that the threat level is displayed. If the user hovers over their cursor over a specific alert, or clicks on one of the alert triangles, then the compound being released are displayed and the details of the current alert level will be shown. When an alert has been clicked on, the display will show both a text description about the alert as well as a still image. The user can click on the ‘play’ button and the interface will play a series of image stills from before the current image and from after the incident.

Connecting the Profiler to a Plant’s Control System

To optimally use the scanfeld early warning system, it’s recommended to integrate the alert events into the Distributed Control System (DCS) or Process Control System (PCS) of your plant so that all the relevant status information and warning events can be managed and controlled easily. The implementation of the user interface into the plant’s operating system is securely facilitated by an OPC Unified Architecture (OPC UA) provided by the scanfeld system. It’s also possible to interface with other standards or to add an extra layer of security by using a suitable broker service.

Any alerts generated by the software module within the scanfeld chemical profiler are sent to the OPC UA client of the user. Therefore, a notification of any events measured by the scanfeld system is realised in the DCS/PCS. In the event of an alert, the notification to the control system contains descriptive information regarding of the event, including, the alert level, the name of the identified compound(s), the name of the scan area where the gas has been detected, and a timestamp of when the event took place. This provides enough information to alert personnel and to take action, but if more information regarding any images, maps, or time series information of the gas release event is required, then the user can refer to the scanfeld user interface.

Overall Outlook

There are many ways of operating the scanfeld to measure gas release events. By adding in the chemical profiler module to your scanfeld set up, you and any staff monitoring an industrial site can gain more in-depth insights into the severity of any gas leaks that present themselves around your site. The scanfeld can measure these events in real-time, but the ease of understanding the severity of the leak enables actions to be taken that are both quicker and are at the appropriate level to the danger being presented. If you’d like to know more about how both the scanfeld and the chemical profiler module can help you to monitor your plant’s emissions safely, then get in touch with us by our contact form, LinkedIn or by email.

René Braun René Braun