The current setup of LNG operators in the industry is to use off-line lab analysis combined with tank level flow measurement. The common drawback however is, analysis may only commence when load transfer is completed. The quality release certificate is usually available a day after the ship has left its berth. Lab operation and manual calculation of calorific value leave room for disputes. Manual handling of cryogenic sample cans is conventional.

Transferring LNG requires a highly accurate measurement of LNG quantity and quality. In the past, the quantity measurement was mainly based on tank level measurement. In recent years, the method has slowly shifted towards dynamic measurement using flow-meters. The quality measurement is usually based on a lab analysis of a representative sample of the LNG that was loaded.

KROHNE developed the L-QRS LNG quality release software package. The L-QRS software includes ISO 8943, GPA 2172, ASTM 4784, ASTM E178 and GIIGNL calculation methods, with correct implementation of these methods certified by NMi. To verify the performance of the instrumentation used for measurement of the LNG, the integrated CalSys module offers analyser management and data acquisition (AMADAS) functionality, amongst others per ASTM D3764, ASTM D6299 and OP 97-30425.