What is scaling in relation to sensor signals?

• A. It involves calibrating the sensor with a new offset
• B. It changes the sensor's measurement units to display voltage only
• C. It converts the raw sensor output into engineering units using a scale
• D. It duplicates the signal for redundancy

Answer: (C)

Scaling maps a raw sensor signal into meaningful engineering units by applying a linear transformation. The sensor’s output—whether voltage, resistance, or ADC count—is converted into a real-world quantity (like degrees Celsius, meters, or psi) using a slope and offset determined from calibration or the sensor specification. For example, a sensor that provides a 0–5 V output to cover 0–100°C uses a formula such as temperature = a × voltage + b, where a and b come from calibration. This lets you read and use the actual physical quantity rather than the raw electrical signal. The other ideas—changing the offset to rezero, displaying only voltage, or duplicating the signal for redundancy—do not describe converting the raw signal into engineering units.