The field tests of WT-1 Fog Detectors are described and the acquired data during the tests are analyzed statistically. The absent rate of observation data from the WT-1 and FD12P, the correlation coefficients of WT-1 with visual observation and FD12P, the conformability of the three measurements and the variation trend of the difference with time are calculated. Based on the analysis results, the advantages and disadvantages of the detector are discussed. In comparison with Vaisala's visibility sensor FD12P, the difference between WT-1 Detector and FD12P is described, and improvement suggestions are proposed.