Visual inspection cannot prove that an ESD surface is working. A bench mat, floor mat, rack, tray, or laminate may look acceptable while its resistance value has moved outside the safe range. Surface resistivity testing gives the ESD team a measurable way to find these hidden gaps.
What should be tested
Common test points include workbench mats, floor mats, table tops, trolleys, storage racks, PCB carriers, conveyor surfaces, and packaging areas. Any surface that touches sensitive components should be included in the test plan. Do not limit testing to new installations; ageing, contamination, cleaning chemicals, and physical wear can change performance over time.
Why records matter
Single readings are useful, but trends are better. If a bench surface is slowly drifting, maintenance can act before it fails. If one area repeatedly shows high readings, it may point to a broken ground path, incorrect cleaning method, or non-ESD material introduced into the process.
Use the correct instrument
Marvel Products’ Digital Surface Resistivity Meter measures surface resistance and resistance to ground over a wide range for ESD protective materials. For a broader list of audit instruments, see ESD Instruments.
Surface testing should be part of incoming inspection for new ESD materials, routine audits for production areas, and corrective action after any ESD event. It replaces guesswork with evidence and helps maintain the ESD control plan across the full shop floor.