How is the overall accuracy of the STL70 / ETL70?

The STL70 / ETL70 is a kit system. The measuring unit and the measuring scale are sold independent.

The information about the STL70 / ETL70 accuracy is only about the sensor. For the overall accuracy, we also have to take the magnetisation accuracy of the magnetic tape into account.

There it is important to know, that the system is a positioning system. The repeatability is very high (< 1 µm). But if you want to measure a distance, you have to add some accuracy values.

Which values do we have?

• accuracy read head: 10 µm
• accuracy measuring tape each meter: 30 µm

Depending on the length of the system, you take for each meter the accuracy value 30 µm + one time the accuracy of the read head (10 µm).

This means, the accuracy is like this:

• 1st meter: (1*30 µm) + 10µm = 40 µm
• 2nd meter: (2*30 µm) + 10µm = 70µm
• 3rd meter: (3*30 µm) + 10µm = 100µm
• ...

See also the picture: