What is Analog Signal Scaling?
In industrial automation and electronics, analog signal scaling is the process of converting a raw signal—such as voltage (0-10V), current (4-20mA), or digital bits from an ADC (0-4095)—into meaningful engineering units. These units could represent temperature in Celsius, pressure in PSI, or flow rate in liters per minute.
Scaling is essential because programmable logic controllers (PLCs) and microcontrollers usually read signals as integer values or raw voltages. For a human operator or a control system to make sense of this data, it must be linearised and mapped to a specific range.
How to Use This Calculator
To use the Analog Signal Scaling Calculator, follow these steps:
- Input Value: Enter the current reading from your sensor or controller.
- Raw Range: Enter the minimum and maximum limits of the signal source (e.g., 4mA to 20mA, or 0 to 32767 for a 15-bit PLC input).
- Scaled Range: Enter the physical range the signal represents (e.g., 0 to 150 PSI).
The calculator instantly computes the scaled value using the linear interpolation formula.
Common Applications
This tool is widely used by instrumentation engineers, PLC programmers, and hobbyists working with platforms like Arduino and Raspberry Pi. Common scenarios include mapping a 0-5V potentiometer signal to a 0-100% motor speed or scaling a 4-20mA pressure transducer signal into bar or pascals.
Frequently Asked Questions
What is the 4-20mA offset?
Many industrial sensors use a 4mA baseline instead of 0mA. This "live zero" allows the system to detect a wire break (0mA) versus a valid low signal (4mA). Our calculator handles this by allowing you to set the Raw Min to 4 and Raw Max to 20.
Can I use this for non-linear signals?
No, this calculator is designed for linear scaling. If your sensor (like some thermistors) has a logarithmic or exponential output, you would need a more complex transfer function rather than standard linear mapping.