1.Observation angle(α):0.2° 

2.Angle of incidence(β):-4° 

3.Light source: warm white light-emitting diode 

4.Detector: silicon diode CIE-compliant spectral visual efficiency function V (λ) 

5.Display: liquid crystal digital display meter 

6.Retroreflection coefficient measurement range: 0~1999cd+x-1.m-2

7.Range: 0-1999cd/lx/m2 11.Ambient temperature:-10-50℃, relative humidity<80%. 12. Battery life: about 8 hours