| Test in diffuse light using a hydrogen lamp | Ha etalon only | Measurement of the average FWHM and delta CWL over the full (or a sub-) aperture of the etalon. Values are measured for normal incidence (i.e. in a collimated beam). Measurement of the etalon non uniformity (CWL drift). |
Description and associated procedure |
| Test with Sol'Ex spectrometer using Sun as a light source | Any filters | Measurement of the FWHM, delta CWL over a 10 micron x 4.5 mm surface of the filter. Measured in a collimated beam (f/115) or with the telescope set-up (i.e. telecentric beam at f/27.5 or f/35, double-stacked, etc.). |
Some notes on Sol'Ex Measurement procedure |
| Test in a collimated beam using an hydrogen lamp as a light source | Ha etalon only | Qualitative assessement of the uniformity of the filter over its full aperture. | Description and examples |
| Filter | Test method | f-ratio | Surface measured | FSR | FWHM | delta CWL | Notes |
| Coronado PST etalon #1 |
H lamp | Full-aperture | 9.3 A | 0.61 A | with PST tuned to Ha line at f-35 | ||
| Sol'Ex spectro | f-115 f-35 telecentric f-27.5 telecentric |
10 micron × 4.5 mm | 9.3 A | 0.34 A 0.76 A 0.93 A |
with PST tuned to Ha at f-35 with PST tuned to Ha line at f-35 PST tuned to Ha line at f-27.5 |
||
| Coronado PST etalon #2 |
H lamp | Full aperture | 6.9 A | 0.98 A | with PST tuned to Ha line at f-35 | ||
| Sol'Ex spectro | f-115 f-35 telecentric f-27.5 telecentric |
10 micron × 4.5 mm | 6.9 A | 0.40 A 0.71 A 1.01 A |
with PST tuned to Ha line at f-35 with PST tuned to Ha line at f-35 PST tuned to Ha line at f-27.5 |
||
| Coronado SM40 #1 |
H lamp | Full-aperture | 12.1 A | 0.74 A | negligeable | ||
| Coronado SM40 #2 |
H lamp | Full-aperture | 11.9 A | 0.95 A | 0.85 A | ||
| Coronado SM40 #2 BF5 diagonal | Sol'Ex spectro | f-14.4 | 10 micron × 4.5 mm | 6.9 A | +1.5 A | 2-cavity filter | |
| Coronado SM60 Gen I | H lamp | Full-aperture | 9.8 A | 0.67 A | + 0.48° | ||
| Coronado SM III 60 mm tilt and 60 mm Rich View etalons |
H lamp | Full-aperture | 8.5 A 8.9 A |
< 0.55 A < 0.58 A |
from 0.55 A (center) to 0.60 A (at 25 mm from etalon center) from 1.20 A (center) to 1.25 A (at 20 mm from etalon center) |
||
| Lunt LS40FHa | H lamp Spectro |
. collimated (f/115) |
Full aperture 7 micron × 6 mm |
11.8 A 11.8 A |
0.63 A 0.57 A |
+0.31 A +0.36 A |
|
| Lunt LSFHa #2 | H lamp | Full-aperture | 12.0 A | 0.64 A | +0.48 A | ||
| Lunt 40 #2 | H lamp Spectro |
. collimated (f/115) |
Full aperture 7 micron × 6 mm |
10.7 A 10.7 A |
0.61 A 0.56 A |
+ 0.32 A + 0.38 A |
|
| Lunt 40 #4 | H lamp | Full-aperture | 12.0 A | 0.64 A | +0.21 A | ||
| Acuter 40 | H lamp | Full-aperture | 11.0 A | 0.64 A | NR | ||
| Heliostar 76 #1 | Spectro | collimated | Full-aperture | 11.0 A | 0.25 A | ||
| Heliostar 76 #2 | Spectro & H lamp | collimated | Full-aperture | 10.5 A | < 0.30 A |
| Filter | Test method | f-ratio | Surface measured | FSR | FWHM |
| Quark (chromosphere version) #1 | Sol'Ex | f/45 telecentric | 10 micron × 4.5 mm | 40 A | 1.0A |
| Quark (chromosphere version) #2 | Sol'Ex | f/45 telecentric | 10 micron × 4.5 mm | 25.4 A | < 0.45 A |
| Quark (chromosphere version) #3 | Sol'Ex (f=200mm) | f/31.4 telecentric | 10 micron × 4.5 mm | 23.0 A | 0.45 A |
| Quark Combo | Sol'Ex and H lamp | collimated | 10 micron × 4.5 mm and full aperture | 20.1 A | 2.1 A |
| Quark Combo #2 | H lamp Sol'Ex (f=125mm) Sol'Ex (f=125 and 200 mm) |
NR
collimated
f/28 telecentric |
full aperture 10 micron × 4.5 mm 10 micron × 4.5 mm |
31.0 A 31.0 A |
1.2 A 0.9A 1.0 to 1.1 A |
| DayStar PE 0.6A #1 | Hydrogen lamp + spectro | collimated and f/28 telecentric | full aperture 10 micron × 4.5 mm |
26.0 A | 1.0 A |
| DayStar PE 0.6A #2 | Hydrogen lamp | full aperture | 26.4 A | 0.95 A | |
| Solar Spectrum SO1.5 - 0.3A | Hydrogen lamp + spectro | collimated telecentric f/29 |
full-aperture
10 micron × 4.5 mm 10 micron × 4.5 mm
|
24.4 A | < 0.9 A < 0.5 A < 0.8 A (consistent with 0.6 A in collimated beam) |
| Solar Spectrum RG32 - 0.3A | Hydrogen lamp + spectro | collimated telecentric f/29 |
full-aperture
10 micron × 4.5 mm 10 micron × 4.5 mm
|
about 22.4 A | 0.7 A < 0.6 A 0.8 A (consistent with 0.6 A in collimated beam) |
| Filter | Test method | f-ratio | Surface measured | . | FWHM |
| Alluxa Ha 10 A | Sol'Ex | f/35 telecentric | 10 micron × 4.5 mm | 3-cavity filter BW at 10% = 14 A Peak T > 85% |
10.0 A |
| Filter | Test method | f-ratio | Surface measured | FWHM | delta CWL | Notes |
| Barr Associates |
Sol'Ex spectro | f-115 | 10 micron × 4.5 mm | 2.6 A |
-0.7 A |
2-cavity filter temperature coefficient = + 0.01 A/°C |
| Alluxa 1 A | Sol'Ex spectro | f-115 f-22 f-22 f-14.7 |
10 micron × 4.5 mm | 1.4 A 1.45 A at normal incidence 1.55 A at 1.3° tilt 1.7 A at normal incidence |
0.0 A at 20°C +0.3 A (at 30°C) + 0.1 A (at 30°C) 0.0 A (at 30°C) |
1-cavity filter Fused silica, temperature coefficient = + 0.04 A/°C |
| Alluxa 1 A #2 | Sol'Ex spectro | f-115 | 10 micron × 4.5 mm | 1.4 A | + 0.4 A (at 18° - 23°C) | |
| Alluxa 1 A #1 and #2 stacked | Sol'Ex spectro | f-14.7 | 10 micron × 4.5 mm | 0.9 A (filters tilted to Ca K) |
0.0 A | Peak transmisision (filters tilted to Ca K) : filter #1 = 64% filters #1+#2 = 29% |
|
Alluxa 0.37 nm |
Sol'Ex spectro | f-115 | 10 micron × 4.5 mm | 3.8 A | +2.1 A | 3-cavity filter BK7, temperature coefficient = + 0.018 A/°C |
Antlia 393-3 nm |
Sol'Ex spectro |
f-115 |
10 micron × 4.5 mm |
3.6 nm |
+ 0.4 nm |
BW at 10% peak transmission = 4.8 nm |