Determining prism position

Red prism

The table and plots on this page can be used to determine the prism position to use. The table gives the first and last orders and the wavelength range for each prism position. There is likely an uncertainty of +/-1 order, and +/-2 for the points that don't quite fit the trend in the plots below (these odd points are due to having to initialise the prisms between measurements).

Prism position	Order 1	Order 2	lambda 1	lambda 2
45000	61	111	9397	5089
45100	67	115	8555	4912
45200	70	117	8189	4828
45300	73	119	7852	4747
45400	76	121	7542	4669
45500	78	123	7349	4593
45600	80	124	7165	4556
45700	82	126	6990	4483
45800	84	127	6824	4448
45900	86	128	6665	4413
46000	87	130	6589	4345
46100	89	131	6441	4312
46200	90	132	6369	4280
46300	91	133	6299	4247
46400	92	134	6231	4216
46500	93	134	6164	4216
46600	94	135	6098	4185
46700	94	136	6098	4154
46800	95	136	6034	4154
46900	95	137	6034	4123
47000	95	137	6034	4123
47100	96	138	5971	4094
47200	96	138	5971	4094
47300	96	138	5971	4094
47400	95	138	6034	4094
47500	95	138	6034	4094
47600	92	137	6231	4123
47700	94	139	6098	4064
47800	91	137	6299	4123
47900	93	138	6164	4094
48000	92	138	6231	4094
48100	91	138	6299	4094
48200	89	137	6441	4123
48300	89	137	6441	4123
48400	87	136	6589	4154
48500	86	136	6665	4154
48600	84	136	6824	4154
48700	82	135	6990	4185
48800	81	134	7077	4216