In hazardous areas, intrinsic safety type of protection plays an important role in process automation. Intrinsically safe barriers can prevent the formation and ignition of an explosive atmosphere. 

Normally Custody transfer accuracy used in Oil and Gas metering between companies or countries. Accuracy parameter used for measuring or transfer error. When the datasheet mention as Transfer Accuracy,  it means between the output and input signal in the barrier.

MTL5541 transfer accuracy is ≤15uA，as the range is 4-20mA, so the accuracy description can be equivalent to 15uA/16mA≈0.1%;

Chenzhu  IS barrier GS8547-EX accuracy is 0.1% which is equal to 16mA*0.1%=16uA, while the typical accuracy of GS8547-EX is 0.05%(≤8uA)

If the deviation between output and input is smaller, the output can better reflect the real state of the input. So the accuracy value is smaller, the performance is better.