By performing a dynamic contact measuring (DCM), you will see the contact resistance variations. This gives you indications on the contact fingers, lubrication and SF6 contamination. The most common use, however, is to measure the length of the arcing contact without taking the breaker pole apart. To get the arcing contact length, a travel transducer must also be attached.
Another common use is to take a reference graph of the resistance curve, either at type testing of the breaker and then compare it at circuit breaker production routine testing procedures. In field service you compare against the values taken in the factory or during commissioning of the circuit breaker. The comparison routines gives any user a swift and easy way of analysing the circuit breaker main contact.
The SA10 and BTS2000A have built-in current generators (200A DC) for static and dynamic resistance measuring.