Metria RST111, Руководство пользователя, Страница: 9 / 12

9
When the reading Z indicated on the scale ring is
＜
30, the value
σ
readfrom the Table takes (+) sign; if
＞
30, (-) sign
Note: The dispersion angle of the refracting prism: ф = 62°, maximum angle dispersion of Amici prism: 2K= 183.62’,
refractive index of refracting prism: nD = 1.7547, average dispersion of refracting prism: nF-nC=0.02738
Take measuring the average dispersion of distilled water as an example: When temperature is 20
℃
,nD =1.3330
The reading of dispersion value indicated on the scale ring will be:
Turn in a certain direction
Turn in the opposite direction
41.7 41.5
41.6 41.6
41.6 41.6
41.6 41.7
41.6 41.6
41.7 41.6
Average value: 41.64 41.60
Total average value Z = 41.62
Read from the dispersion table:
When nD =1.3330, A = 0.024768 B = 0.032893
When Z = 41.62,
σ
= -0.5716 (for Z ＞ 30, so Z takes negative value)
nF-nC= A+B
σ
= 0.024768 -0.032893×0.5716 = 0.00597