in manulas I found two ways to check the belt tension (one requires a special tool) the other measurement.
Click image for larger version. 

Name:	20200627_222339[1].jpg 
Views:	143 
Size:	44.3 KB 
ID:	13952
There is also a third option for frequency measurement
Click image for larger version. 

Name:	20200627_222137[1].jpg 
Views:	146 
Size:	43.3 KB 
ID:	13953
Click image for larger version. 

Name:	20200627_222302[1].jpg 
Views:	138 
Size:	38.5 KB 
ID:	13954
Unfortunately, my favorite brand of the tool manufacturer in its manual does not give the frequency for Honda NSX. Does anyone know where to find this data?