Kipp & Zonen BREWER MK IV, Инструкция по эксплуатации

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16-10-200716-10-2007
MKIV OPERATOR’S MANUAL 103
Dark Count versus Slitmask Delay should be plotted and compared to the plot shown in the Final
Test Record. The optimum slitmask delay time is that which minimizes the dark count - typically this
delay constant would lie within the range 10 to 16. For the table above the optimum delay constant
is 14.
The new delay constant should agree with the final test record value within an acceptance tolerance
of ±5. If the new constant is significantly different from the final test value then the factory should be
contacted before changing the configuration in the firmware since a complete instrument re-
calibration may be necessary.
SL: Standard Lamp Test
The SL test is a general quality-assurance examination of Brewer performance across the full range
of operational wavelengths. An internal, well-regulated, quartz-halogen 'standard' lamp is used as
the light source. This source produces a continuous light spectrum (unlike the mercury lamp which
emits discrete wavelengths.) which is stable and consistently reproducible. This test should be run
on a regular basis (e.g. twice daily) to establish a set of instrument performance records.
Method:
Type SL. The test runs through the same temperature and foreoptic positioning procedures
described in HG, then waits the obligatory five minutes for the quartz-halogen lamp to warm up.
The program then conducts seven measurement runs over the dark-count channel and the five
operational wavelength channels. Each measurement cycles the slitmask through 20 oscillations,
accumulating the photon counts in the BASIC one-dimensional F() array (described under
Preliminary Data Reduction). These raw counts are printed in the following format:
Brewer Temp = 27 C ( 3.56 V)
C.U.T. CY ZEN MU DRK 1 2 3 4 5
SL0 20:54:25 20 65.63 2.384 32 1102112 1052861 1066768 956627 820941
SL0 20:55:02 20 65.67 2.388 35 1101966 1054190 1067478 957870 821186
SL0 20:55:40 20 65.72 2.392 43 1102630 1053024 1067318 958662 821366
SL0 20:56:18 20 65.76 2.395 36 1101330 1054009 1068002 957890 821567
SL0 20:57:02 20 65.81 2.4 31 1101960 1053736 1068197 957257 820730
SL0 20:57:46 20 65.86 2.404 37 1102690 1052931 1067378 959002 821232
SL0 20:58:24 20 65.9 2.408 43 1102507 1053022 1067047 958135 822097
The SL0 indicates that the Standard Lamp test was performed with Filter Wheel #2 in position 0 (ie
no neutral-density attenuation). CY is the number of slit-mask oscillations over which the counts
were accumulated. ZEN and MU are the current solar-zenith angle and airmass respectively (these
are irrelevant to the SL test and are presented for operator information only). The next six columns
are the photon count totals for the dark channel and the five operational channels. When all seven
measurements are complete the program corrects the raw photon counts for dark count, deadtime,
and temperature-dependence, then prints a series of summary statistics:
20:56:22 Feb 21/85 65.763 2.395 27 C DEG SL 0
Mean1 mean5 MS(4) MS(5) MS(6) MS(7) MS(8) MS(9)
1102170 821302 -623 -426 -488 -694 596 418
+ 483 + 445 + 3 + 5 + 5 + 4 + 15 + 9
The first line shows the time, date, solar-zenith angle, airmass, instrument temperature and test
identification. The second line of data displays the mean corrected count for channels 1 and 5, the
single-ratios MS(4) through MS(7), and the double-ratios MS(8) (the SO
2
ratio), and MS(9) (the O
3
ratio). The derivation and interpretation of these values is detailed under Preliminary Data
Reduction.
APPENDIX F FACTORY TESTS