The analyzer continuously monitors the most important operating conditions. A fault is signaled when any of the following errors is detected: memory failure, loss of power, loss of temperature, loss of fuel, loss of sample flow. A fault is displayed in the display, indicated by an LED and signaled via a relay.
An additional relay signals service requests which indicate changes before a fault might be generated: The reason for the service request is indicated in the display. This can be used to schedule preventative maintenance at a convenient time without risking a malfunction.
The PrevEx analzyers can be integrated into safety-instrumented systems according to the following safety levels:
- SIL2 for a single analyzer and SIL3 for a redundant analyzer pair according to EN 61508 (Exida certificate), low demand
- Performance Level d (PL d) for a redundant analyzer pair according to EN ISO 13849-1 for up to continuous demand rates (this safety level is used for feedback control systems for the LEL concentration using the concentration reading of the analyzers, e.g. in solvent dryers according to EN 1539 or for the dynamic dilution of waste gas streams before thermal oxidizers)
The requirements set forth in the respective safety manual must be met in order to achieve the safety levels.