Why can’t I test both bulk tank and animal samples in the Go Device?

Bulk tank samples require a REF

animal samples under conditions can run for 30 days (delvotest T) 21 days (Delvotest SPNT) with a stored in memory reference sample. 

It is important to read the test at control time when the sensitivity is the best. For example, irregular storage conditions can increase the control time. Therefore a test with standard negative milk is periodically needed to ensure to define the correct reading moment.