Kipp&Zonen Brewer MkIII - Manual (Page 105)

MKIII OPERATOR'S MANUAL 102
Method:
The command HG is issued.
The program will read and display the current Brewer temperature, and a checklist of required
foreoptic settings will then be displayed:
*** measurement procedure ***
check:
1 - filter #1 to position #1
2 - filter #2 to position #0
3 - open iris
4 - rotate director prism to lamps
* press return when ready *
These controllable elements will be set automatically.
After a five-minute lamp warm-up period the program will perform a series of intensity
measurements over a micrometer step-number range of 50 to 280 as described earlier. The photon
count for each observation point is displayed on the screen. You should observe a peaking trend
as the micrometer passes through step position 150 (sample number 15). When the micrometer
has completed its there-and-back journey the program computes and displays the five correlation
coefficients corresponding to attempted curve matchings (between the measured spectrum and the
internally-stored reference spectrum) at step positions 110, 130, 150, 170, 190. From these
measurements the mercury calibration point is determined and printed in the following format:
Brewer Temp = 29 C (3.66 V)
190112 ( .987) HG CALD AT STEP# 298.47 SET TO STEP# 286 9540
This report indicates that at 19:01:12 (C.U.T.: Co-ordinated Universal Time, also known as GMT), a
maximum spectral-matching correlation coefficient of 0‘987 was obtained for an (interpolated)
mercury calibration point of 298.47. The operational setting of the micrometer is arrived at by
subtracting the 'offset' retrieved from the instrument Constants File (the offset is 12 in this case)
from 298.47, then truncating the result. 9540 is the peak count across all 24 observation points.
The micrometer is automatically repositioned to the operational point (step #286 in this case), and
the test ends.
Should the interpolated calibration point fall outside the [147.00..149.99] acceptance range, the
micrometer is automatically repositioned at the truncated calibration minus the offset and the test is
repeated until the interpolated calibration point lies between 147 and 150. A sample printout for an
HG test which converged in two iterations is shown below (the offset for this instrument is 10
steps):
BREWER TEMP = 26 C ( 3.52 V)
103409 ( .9919 ) HG CALD AT STEP # 296.1 SET TO STEP # 286 60871
103651 ( .9927 ) HG CALD AT STEP # 287.0 SET TO STEP # 286 61019
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.
APPENDIX F FACTORY TESTS