Accessories for Control Panels

Internal Safety Barrier

For applications where the gas detector heads (or other sensor type) are sited in a potentially explosive atmosphere, a safety barrier must be fitted to each individual channel in order to limit the maximum voltage and current under a fault condition (e.g. short circuit) such that an incendive spark cannot be created. Where suitable, the internal safety barrier shown above may be fitted to each of the required channels within the control unit. This can either be fitted at the time of manufacture (where requested) or at a later time if the system is extended by the installation of additional detectors.

External Safety Barrier

These are fitted at the electrical intersection between the hazardous and non-hazardous area. They limit the electrical power that can be passed into the hazardous area under both normal working and fault conditions. The power is limited such that an incendive spark or heating caused by the circuit concerned will not cause ignition of the gas that may be present within the hazardous area. Different zener barrier arrangements are used according to the application.

Traffic Lights

These are an effective means of providing visual and audible indication of whether it is safe for personnel and/or vehicles to enter a hazardous area.

The Status Scientific Controls traffic light consists of three visual indicators together with an audible alarm. The green indicator is powered by high brightness LEDs which are on continuously under safe conditions. The amber light is a flashing xenon strobe which can be used to indicate when a hazardous gas level is rising (Alarm Level 1). The red light is a flashing xenon strobe which would normally be set to flash when the gas has reached a dangerous level either flammable, toxic or low/high oxygen (alarm Level 2). The audible alarm can be set to sound at either the Alarm Level 1 or 2 and could be independently muted at the control panel if required.

Audible And Visual Alarms

These are available in either non-certified, intrinsically safe or explosion proof versions according to the classification of the hazardous area where the equipment is to be installed. They can be used at strategic points around a site to give local warnings of rising gas levels or other events.