Mass flow cut off and Live Zero monitoring significance

Hi friends,

can anyone tell me the significance of Mass flow cut off and live zero monitoring significance in detail.

One more doubt is as below:

if i set my mass flow cut off to 5g/s and live zero is 4.99 g/s when there is no fluid  flow . does that mean the 4.99 g/s is error due to installation.

If it is so does it have impact on my performance if mass flow meter. Whats the error acceptable to maintain the manufacturer claimed performance of 0.1%