According to regulations, ambulatory glucose meters should have a margin of error of plus or minus 20% in measuring blood glucose levels. In other words, if the measurement result of the ambulatory glucose meter does not differ from the actual blood glucose level by more than 20%, the manufacturer is not liable for the claim. However, if the error is more than 20%, and this is due to a quality problem with the device itself, then the manufacturer should be held liable for the claim.
It is important to note that when using a glucose meter, you should follow the instructions to ensure that the measurements are accurate. If there is an error in the process of use, you should contact the manufacturer or after-sales service personnel in a timely manner to avoid unnecessary losses.