In order to evaluate the stability we have done 48 experiments without delay.
This experiment was repeated twice on D1.
The variation for RGB is less than 0.1%.
The experiment was redone using a delay of 600s between them. The main variation is probably due to temperature changes.We observe that the changes now can reach up to 0.5% and is very related to the color.
In order to confirm the temperature importance this experiment was redone by acquiring as well the temperature.
We can clearly see a inverted correlation between the red variation and the temperature.
When repeating the same experiment blank (no sample) / sample (no sample) + blank / sample, etc.
Sample 1:
- 0.54
- 0.55
- 0.54
- 0.56
- 0.56
- 0.55
- 0.55
Sample 2:
- 1.2
- 1.27
- 1.24
- 1.24
- 1.25
- 1.22
When we insert / remove the cuvette we observe the following values
- 197474
- 191596
- 190325
- 173893
- 190822
- 201730
- 202131
- 190058
- 205585
- 186595
What we observe is that the orientation of the cell is critical. If we force the rotation of the cell between parallel or distort we have the followings values:
- 229460
- 183143
Turning of 90° the cell as also big impact depending I guess the quality of the cuvette. In our case (with cheap plastic ones) we observe:
- 219035
- 259780
- 215050
- 263096
- 217012
- 249061
- 213230
It appears that when measuring the difference of absorbance between an empty tank and a tank full of water, the values were aberrants. Indeed the energy was higher with the water than without. One of the problem could be that there is a space inside the tank hole that could lead to refraction. We designed a piece to hide this space using 3D printing.
We obtained theses results that differ from the one with the ones without the piece:
| Empty tank without piece | R | G | B |
|---|---|---|---|
| Mean of energy | 353033,4 | 317978,2 | 59185,9 |
| SD | 149,01 | 23,69 | 5,30 |
| Tank H2O without piece | R | G | B |
|---|---|---|---|
| Mean of energy | 472297,8 | 421643,8 | 59170,7 |
| SD | 115,89 | 106,08 | 3,02 |
| Empty tank with piece | R | G | B |
|---|---|---|---|
| Mean of energy | 327422,2 | 322457,5 | 397948,8 |
| SD | 43,81 | 28,99 | 131,21 |
| Tank H2O with piece | R | G | B |
|---|---|---|---|
| Mean of energy | 414108,5 | 422623,7 | 50511,6 |
| SD | 53,73 | 43,92 | 33,59 |
| Test orientation with piece | R | G | B |
|---|---|---|---|
| Mean of energy | 61153 | 141100,7 | 177537,6 |
| SD | 484,21 | 1089,87 | 1050,4 |
| Test orientation without piece | R | G | B |
|---|---|---|---|
| Mean of energy | 91207,2 | 256636,7 | 181855,8 |
| SD | 7635,79 | 22432,84 | 711,92 |
Here are stored all of our measures for the hacking of the case: