Low Pressure Sodium (LPS) lamps emit a narrow 589 nm monochromatic beam — the only light source that produces the sharp, high-contrast interference fringes required for precision optical inspection. This collection brings together the LPS lamps and compatible ballasts used in optical flatness measurement, Newton's rings analysis, semiconductor wafer inspection, LCD panel defect detection, and mechanical seal flatness verification.

Unlike broadband light sources, the single-wavelength output of an LPS lamp eliminates chromatic noise and allows technicians to resolve surface deviations at the sub-micron level — making it an indispensable tool in metrology laboratories, semiconductor fabs, and precision manufacturing quality control.