Methods to improve the performance of the surface plasmon resonance array sensor at ambient temperature are studied. A self-reference channel was used to eliminate the long-term drift caused both by the temperature and the light source. The Hilbert–Huang transform-based signal post-processing algorithm was employed to improve the signal-to-noise ratio and reduce high-frequency noise. Finally, an adaptive moving-average method was adopted to reduce noise while preserving important high-frequency signal characteristics. A combination of these methods decreased the baseline noise to 3.6×10−6 refractive index unit. Acceptable repeatability was achieved with relative standard deviation 2.20% (n=8 ). The limit of detection of NaCl was measured at 69 mg/L .