scope:

NTA 8399 provides guidelines for the detection of diffuse VOC emissions using optical gas imaging (OGI). The NTA focusses on portable, passive, optical camera systems that enable volatile organic compounds to be made visible in real time. Non-portable, stationary systems that do not allow such flexible use are not included in the scope of this NTA, as these systems often have their own specific scopes. Different users may have different reasons for using OGI. In general, safety, the environment and loss of product are the drivers for applying OGI. OGI can be used in different ways (see also annex C): - as part of an LDAR (leak detection and repair) programme; - to visualize diffuse VOC emissions of storage tanks; - to visualize diffuse VOC emissions that are released while loading operations; - other applications. This NTA lays down the requirements the IR camera shall meet and the method to be followed to enable reliable statements to be made. Annex D of the NTA contains examples of inspection forms for recording OGI measurements on storage tanks. In addition to the obligatory emission calculations (e.g. E-PRTR (European Pollutant Release and Transfer Register) or environmental annual reports) a measurement protocol based on the Handboek emissiefactoren [Emission Factors Handbook] [4] can be used for the measurements on storage tanks. If OGI is used for monitoring emissions from tanks pursuant to legislation and regulations, the measurement protocol to be used will have to be coordinated with the authorities. Using the IR camera as a measuring instrument for the LDAR programme is not in keeping with the Dutch Meetprotocol voor lekverliezen [Measurement protocol for leakage losses] [3] and the authorities will have to authorize this as part of their permit activities. This NTA does not include a measurement protocol for conducting LDAR measurements based on OGI.