Dust and air quality levels are continuously monitored against specified criteria. This is usually a fixed concentration level, although Noise Sentinel may be configured with different thresholds for different times of day and working practices, including specific days of the week. Should levels exceed a stated criterion, an alert is generated and shown in the Real-time Control application. Alerts may trigger an email to be sent to a defined distribution list, or a text message to specified mobile phones. Alerts are generated within a few seconds of exceedance, enabling prompt action to be taken. Set warning levels below limit levels to create alerts to prevent a breach taking place. The alert dialog shows the details of the location, time, level recorded and the compliance limit.