Electrical contacts are used in any electronic system where current is being passed to a surface. They’re found in switches, circuit breakers, connectors, and relays. Common metals used as bulk conductors for these electrical components include copper, aluminum, silver, and their respective alloys. Other metals such as tin, tin alloys, and certain silver alloys are used as coatings for the contacts.
Electrical contacts are prone to damage and deterioration since they’re used frequently. For this reason, they need to undergo quality checks in the form of a contact resistance test, or more commonly known as ductor testing. This test can detect issues like loose connections, eroded contact surfaces, and tension levels, among many others.
How Is Ductor Testing Done?
There are two commonly used methods in ductor testing: visual and instrumental inspection. During visual inspection, the contacts are examined for any deformities or signs of pitting corrosion.
Instrumental inspection comes next, and during this stage, a fixed current will be injected through the contacts to measure the drop of the voltage across. The resistance value (Ohm) will be calculated and
compared with the manufacturer’s specifications. This value will also be compared with the results from previous tests if there have been any.
Criteria to Observe
For the ductor test to be accurate and reliable, the same testing conditions, such as the voltage, test connections, and duration of tests, must be observed every single time. Atmospheric factors that might affect the test results should also be recorded. You also have to take note of the type of metal on the contact’s surface and the contact pressure. After gathering data from the test results, have a trusted electrical contact manufacturer interpret the data and provide you with recommendations for the next measures.
During the succeeding tests, you must keep records of the following details:
- The equipment’s name and model
- The instrument used for ductor testing along with its brand, voltage, and range
- The testing time and date
- The actual values of the test results
- The operating temperature of the electronic device being tested
- A plot that displays trends in all the test results
Ductor testing allows you to detect issues with your electrical contacts, so they can be addressed immediately before matters become worse. Ductor testing is also done to avoid power outages or short circuit incidences that can interrupt business operations. If you look at it from a bigger perspective, ductor testing can even contribute to worker safety and legal compliance.