误差来源 10 :!λ=1.54A △d= λc0Sθ △0 8- 2sin20 6- The fractional error approaches zero as 0 approaches 90. 4- △0=0.01° 2- △0=0.02° △0=0.005° 0 20 40 60 80 Bragg angle,theta (0 20 40 60 80 0 2 4 6 8 10 delta d Bragg angle, theta (o ) The fractional error approaches zero as  approaches 90o . Δ𝑑 = 𝜆𝑐𝑜𝑠θ 2𝑠𝑖𝑛2θ Δθ Δ θ = 0.005° Δ θ = 0.02° Δ Δ θ = 0.01° d (10 -3Å) 𝜆=1.54Å 误差来源