Sensors
Choice of sensors
In order to obtain reliable and accurate measurement data, the installation of high quality sensors is crucial.
Learn more about the impact of measurement errors on the annual energy production (AEP)
| Generated error by 1% measurement error | Impact on AEP | |
|---|---|---|
| Anemometer | Δ1% wind speed measurement error (Up to Δ6% energy, if anemometers are used to calculate the wind profile.) | Δ3% energy |
| Wind vane | No direct linear relation, but will lead to poor wind farm design. | |
| Air pressure sensor | Δ1% air pressure measurement error | Δ1% energy |
| Temperature sensor | 1° measurement error | 0.35% energy |
| Air humidity sensor | (at 40°C) 1% measurement error | 0.05% energy |
Slope & Offset
Slope & Offset Explained: Making Sense of Your Measurements!
When measuring data, for example with a datalogger, it’s crucial to accurately convert electrical signals into actual physical values. This is where Slope and Offset come into play!
Imagine the relationship between what your sensor measures (an electrical signal) and what it truly represents (e.g., temperature, pressure) is a straight line. This relationship can be described by a simple equation:
Y = mX + b
Where:
- Y is the actual, measured value (e.g., temperature in °C).
- X is the electrical signal from your sensor (e.g., voltage in mV).
- m is the Slope – it tells you how much the actual value Y changes when the electrical signal X changes. Think of it as the conversion factor.
- b is the Offset – it shifts the line up or down, correcting small deviations that might occur, for example, due to calibration.
When are Slope & Offset used?
Whenever the relationship between the sensor signal and the physical value is linear, meaning it can be represented as a straight line.
How are they calculated?
• Slope (m): This is calculated by dividing the change in the measured value (Y) by the change in the electrical signal (X). You can also think of it as “rise over run.”
• Offset (b): For the offset, you use the slope and a known point on the line. This establishes the starting position of the line on the Y-axis.
In summary:
With Slope and Offset, we ensure that the electrical signals captured by our devices are precisely converted into accurate and meaningful measurement values. This way, you always get precise results!