Hi
We tested water level sensing using FDC2214.
And we got the following result.
| TEST1 | Level Up | ||
| Ref (pF) | Level (pF) | Level-T1-Water | |
| Empty | 85.371 | 87.209 | |
| 1 cm | 85.703 | 87.604 | 1.189759036 |
| 2 cm | 85.787 | 87.977 | 1.846153846 |
| 3 cm | 85.806 | 88.319 | 2.551724138 |
| 4 cm | 85.811 | 88.541 | 3.027272727 |
| TEST2 | Level Down | ||
| Ref (pF) | Level (pF) | Level-T2-Water | |
| Empty | 85.412 | 87.261 | |
| 1 cm | 85.69 | 87.609 | 1.251798561 |
| 2 cm | 85.766 | 87.975 | 2.016949153 |
| 3 cm | 85.792 | 88.315 | 2.773684211 |
| 4 cm | 85.811 | 88.541 | 3.20802005 |
| TEST3 | Level Up | ||
| Ref (pF) | Level (pF) | Level-T3-Water | |
| Empty | 85.294 | 87.136 | |
| 1 cm | 85.653 | 87.567 | 1.200557103 |
| 2 cm | 85.735 | 87.943 | 1.829931973 |
| 3 cm | 85.763 | 88.287 | 2.454157783 |
| 4 cm | 85.77 | 88.531 | 2.930672269 |
To obtain the calculated level, we used the following:
where
href = 1 cm,
Cre is capacitance of reference liquid electrode when tank is empty, because environmental electrode was not used.
We have tested 3 times with same environment.
In the TEST1, water level had increased (level up).
In the TEST2, water level had decreased (level down).
And water level had increased again in the TEST3 (level up).
We think the result of TEST2 is a little different from the other results.
Question:
What do you think the results we obtained?
Could it be wrong that we had different result between water level up and water level down?
BestRegards
