Illinois Climate Network: Instruments used in the Illinois Climate Network
| Parameter | Instrument | Sampling Frequency | Accuracy | Unit of measurement | Height of measurement | Notes |
|---|---|---|---|---|---|---|
| Air Temperature | EE 181 sensor | 10 seconds – data averaged over an hour |
+/- 0.2° C at -20°C | degrees Celsius (°C) | 2 m above ground | Housed in a naturally aspirated radiation shield |
| Relative Humidity | EE 181 sensor | 10 seconds – data averaged over an hour |
<
+/- (1.3 + 0.003RH)% RH (0 – 90% RH) +/- 2.3% RH (90 – 100% RH) |
percent (%) | 2 m above ground | Housed in a naturally aspirated radiation shield |
| Wind Speed | RM Young 05103 anemometer | 10 seconds – data averaged over an hour |
±0.6 mph or 1% of reading | meters per second (m/s) | 10 m above ground (prior to winter 2011/2012 measurements made at 9.1 m (30 ft)) |
|
| Wind Direction | RM Young 05103 anemometer | 10 seconds – data averaged over an hour |
±0.3° or 1% of reading | degrees (°) | 10 m above ground (prior to winter 2011/2012 measurements made at 9.1 m (30 ft)) |
|
| Solar Radiation | Eppley Laboratory 8-48 pyranometer and Apogee SP-510 | 10 seconds – data averaged over an hour |
+/- 2% (Eppley) and +/- 3% (Apogee) | kilowatts/ square meters (kW/m2) | ||
| Precipitation | Ott Pluvio rain gage | 1 minute – data totaled for hour |
+/- 0.005 in or 5% | inches (in) | opening at 1 m above ground | Belfort rain gages were used at stations prior to summer/fall 2008. |
| Barometric Pressure | Campbell Scientific barometers (105 or SBP270) | 10 seconds (SBP270) or 10 minute (105) – data averaged over an hour |
+/- 0.5 mb at 20°C (105) +/- 0.2 mb (SBP270 |
millibars (mb) | ||
| Soil Temperature | Campbell Scientific 107 sensor | 10 seconds – data averaged over an hour |
+/- 0.4° C for range of -24 to 48°C | degrees Celsius (°C) | under sod – 4” and 8” below ground under bare soil – 4” below ground |
|
| Soil Moisture | Stevens hydraprobe sensor | 1 hour | +/- 0.03 wfv | water fraction by volume (wfv) | 2, 4, 8, 20, 39, and 59” below ground |