|
|
|
The following sensor specifications, (except sensor heights, are provided by the particular sensor manufacturer):
-
Total solar radiation (pyranometer)
-
Soil temperature (thermistor)
-
Air temperature/relative humidity (HMP35)
-
Wind direction (wind vane)
-
Wind speed (anemometer)
-
Precipitation (tipping-bucket rain gauge)
|
|
| 1.
Total solar radiation (pyranometer)
|
|
|
|
Sensor:
|
Pyranometer--high stability silicon photovoltaic detector (blue enhanced)
|
|
|
Model:
|
LI200S
|
|
Maker:
|
Li-Cor
|
|
Height:
|
10K ohm potentiometer vane
|
|
Sensitivity:
|
±5% error under natural sunlight conditions. Typically 80 micro Ampere per 1000 watts per square meter.
|
|
Linearity:
|
Maximum deviation of 1% up to 3000 watts per square meter.
|
|
Response time:
|
10 micro seconds.
|
|
Correction:
|
Cosine corrected up to 80 degrees angle of incidence.
|
|
Azimuth:
|
±1% error over 360 degrees at 45 degrees elevation
|
|
|
| 2.
Soil temperature (thermistor)
|
|
|
|
Sensor:
|
Soil Thermistor--Fenwal Electronic UUT51J1 thermistor in water resistant coating.
|
|
|
Model:
|
107b
|
|
Maker:
|
Fenwal/ modified by Campbell Scientific Inc.
|
|
Height:
|
15 cm (6 in) below soil surface under irrigated grass.
|
|
Accuracy:
|
Worst case ±0.4 degrees C over -33 to 48 degrees C, ±0.5 degrees C at -40 degrees C
|
|
|
| 3.
Air temperature/relative humidity (HMP35)
|
|
|
|
Sensor:
|
Fenwall Thermistor/HUMICAP H-sensor
|
|
|
Model:
|
HMP35C
|
|
Maker:
|
Vaisala/modified by Campbell Scientific, Inc.
|
|
Height:
|
1.5 m
|
|
Range
|
0 to 100% RH, -35 to +50 degrees C
|
|
Accuracy:
|
±2% RH (0-90% RH), ±5% RH (90-100%), ±0.1 °C over -24 to 48 °C range
|
|
Note:
|
Both sensors are enclosed in a 12-plate naturally aspirated radiation shield made by R. M. Young.
|
|
|
| 4.
Wind direction (wind vane)
|
|
|
|
Sensor:
|
2.0 meters
|
|
|
Model:
|
024A
|
|
Maker:
|
Met-One
|
|
Height:
|
2.0 meters
|
|
Range:
|
0-360 degrees
|
|
Output:
|
0-10 * 10³ Ohms
|
|
Threshold:
|
0.45 m per sec (1 mph)
|
|
Accuracy:
|
±5%
|
|
Delay distance:
|
less than 1.3 m
|
|
|
| 5.
Wind speed (anemometer)
|
|
|
|
Sensor:
|
Three-cup anemometer utilizing a magnet activated reed switch whose frequency is proportional to wind speed
|
|
|
Model:
|
014A
|
|
Maker:
|
Met-One
|
|
Height:
|
2.0 meters
|
|
Range:
|
0-45 m per sec (0-100 mph)
|
|
Threshold:
|
0.45 m per sec (1 mph)
|
|
Gust Survival:
|
0-53 m per sec (0-120 mph)
|
|
Accuracy:
|
1.5% or 0.11 m per sec (0.25 mph)
|
|
|
| 6.
Precipitation (tipping-bucket rain gauge)
|
|
|
|
Sensor:
|
Tipping-bucket rain gauge with magnetic reed switch.
|
|
|
Model:
|
TE525MM
|
|
Maker:
|
Texas Electronics
|
|
Height:
|
1.0 meters
|
|
Orifice:
|
24.5 cm (9.644 in)
|
|
Resolution:
|
0.1 mm
|
|
Accuracy:
|
±1% at 5 cm per hr or less.
|
|
|
