End of Line Testing Improvements

Posted on Monday, September 15, 2014 in UEA Blog

The slip ring industry is always revolving and evolving (pun intended) and perhaps no better area of this evolution is our end-of-line testing capabilities. Being that a slip ring is a rotational continuity device, in the past we have checked for continuity during several steps of the assembly process, and then upon customer request at the end when we will perform an isolation and continuity test on the entire slip ring and harness assembly. For some of our higher voltage applications, over 240 volts, we also will perform Hi Pot testing. This process includes checking each circuit for isolation with an electrical potential difference of two times the circuits rated voltage, plus 1000 volts, plus an additional 20%. Until recently that was the extent of our end-of-line testing. Now, we have the ability to test for total throughout resistance, electrical noise testing of a dynamic system, and rotational torque. We use a 4 wire Kelvin technique when testing for resistance to provide the most accurate resistance numbers for our system. This is preferred because we typically see very low resistance numbers between 1 mOhm – 200 mOhm depending on the size and length of cable. UEA also has multiple cable test systems in house that can be programmed to a specific slip ring assembly to quickly perform resistance testing. Taking that a step further, UEA has performed electrical noise testing on a dynamic system by essentially taking multiple data points from the resistance test and calculating the variance over a specified length of time. To do this test, UEA uses a custom designed one-of-a-kind slip ring testing system. An additional feature of this system is to record the starting and running torque of the slip ring assembly. In the end, all of this testing gives UEA the best possible understanding of our products so that we can efficiently track how various engineering changes affect product performance both at the beginning and throughout a products life. These new testing procedures will help to ensure that UEA is providing the best possible quality for the specific slip ring application.