2. Clean test probes regularly

Cleaning mats can be used to clean pointer plunger tips. All other tip styles are cleaned with a brush or paintbrush to remove residue. Contamination such as solder residues and flux stick to the plunger tip and can cause increased resistance or pseudo errors. Extreme care should be taken when cleaning with a brush. Side loads on individual pins during cleaning can cause permanent deformation of the plunger. Brushes with metal bristles should not be used. An appropriate contact cleaning mat is helpful here. This is cut to the size of the DUT and placed in the test fixture instead of the DUT. When closing the test fixture, the test probes pierce the cleaning mat. The specialised composition of the contact cleaning mat creates the cleaning effect. For stubborn contamination, the process can be repeated several times.