RC-SPC1K is an thick film technology rain sensor.
This device is realized in Allumina (AL2O3) substrate, this material is endowed a big reliability from an electrical thermal point of view.
The sensor consists of three parts :
1) Capacitive sensor (Face A)
2) Heater generator
3) Temperature Sensor
The Face A is the sensitivity area (capacitiver sensor) this area is expost to natural agent (rain) in dry condition the value of the capacitor is nominal 105pF,
In presence of the rain the capacitance goes to high valued respect the dry contidion the ratio changing is over 420%, in the table N.1 you can verify the capacitance change characteristics.
The Face B is present the heating circuit and the NTC component and the connection interface (six pads).
Checking these 3 functionsControllando queste 3 funzioni :
- Measure the capacitance (Table 1)
- Measure the environment temperature (Table 2)
- Heater control (Tabella 3)
It's possible establish if it's raining or not.
| Electrical Parameters |
|
| Capacity Value |
100 pF 10% |
| R Value (heater) |
42 Ohm 10% |
| Thermistor NTC Value |
1KOhm 10% |
Table 1 - Capacitive change characteristic
| Sensitivity |
|
Capacitance |
Ratio |
| % DRY |
% WATER |
pF |
% |
| 100 |
0 |
100 |
0 |
| 75 |
25 |
180 |
80 |
| 60 |
40 |
280 |
170 |
| 50 |
50 |
390 |
250 |
| 0 |
100 |
>550 |
>370 |
|
Table 2 - NTC Characteristic
| Temperature °C |
R nominal (Ohm) |
| -5 |
3572 |
| 0 |
2844 |
| 5 |
2280 |
| 10 |
1839 |
| 15 |
1492 |
| 20 |
1218 |
| 25 |
1000 |
| 30 |
825 |
| 35 |
685 |
| 40 |
571 |
| 45 |
479 |
| 50 |
403 |
| 55 |
341 |
| 60 |
290 |
| 65 |
247 |
| 70 |
212 |
| 75 |
182 |
| 80 |
157 |
| 85 |
136 |
|
Table 3 - Heater Time
| Time (sec) |
Temperature Sensor (°C) |
| 0 |
27 |
| 15 |
40 |
| 30 |
50 |
| 45 |
60 |
| 60 |
70 |
| 75 |
75 |
| 90 |
77 |
| 105 |
78 |
| 120 |
81 |
| 135 |
83 |
| 150 |
85 |
|
