The Nominal Value is the designated or theoretical value of a component or parameter. It serves as a reference point for specifications and design, representing the "ideal" value under perfect conditions.
In practice, actual measured values often deviate from the nominal value. These discrepancies can be caused by several factors:
- Manufacturing tolerances
- Environmental conditions (e.g., temperature drift)
- Load variations
Examples of Nominal Value vs. Actual Value
Electronic Components
A resistor might have a nominal value of 100 Ω. However, due to its tolerance specification (e.g., ±1%), the actual resistance may measure 99.7 Ω or 100.2 Ω.
DC Power Supplies
When a programmable power supply is set to a nominal output of 12.000 V, the actual measured output might be 12.002 V. This difference depends on the unit's setting accuracy and line/load regulation characteristics.
General Systems
A car's electrical system is described as having a nominal voltage of 12 V. However, the actual operating voltage typically rises to around 13.8 V when the engine is running to charge the battery. This highlights how the nominal value acts as a standard classification rather than a constant operational value.