Resistor tolerance indicates the permissible deviation of a resistor’s actual resistance value from its stated or nominal value. This deviation is typically expressed as a percentage. For instance, a 100-ohm resistor with a 5% tolerance can have an actual resistance value between 95 ohms and 105 ohms. This range is determined by multiplying the nominal resistance by the tolerance percentage and then adding and subtracting the result from the nominal resistance value. The formula used to establish this range is: Actual Resistance = Nominal Resistance (Tolerance Percentage Nominal Resistance).
Understanding a resistor’s tolerance is critical for circuit design and analysis. It ensures that circuits function reliably within expected parameters, especially in sensitive applications where precise resistance values are essential. Neglecting tolerance can lead to unpredictable circuit behavior, component failure, or performance degradation. Historically, resistor tolerance was wider, demanding careful component selection. Improvements in manufacturing processes have led to resistors with tighter tolerances, enhancing precision in electronic devices.
