indicator-diagram

indicator-diagram

A technician analyzes an indicator-diagram on a computer screen.

Definition

Noun: An "indicator-diagram" is a graphical representation, typically a chart or plot, that shows the relationship between pressure and volume (or other variables) within a cylinder of an engine or pump over a complete cycle of operation. It is used to analyze the performance and efficiency of the machine.

Usage Examples
  • (The chart showing pressure and volume changes was examined.)
  • (The graph is created from real-time measurements.)
Advanced Usage
  • "To take an indicator-diagram": To record the pressure-volume data from an engine's cylinder using a mechanical or electronic device.

    • The technician took an indicator-diagram of the steam engine to check for valve timing issues. (A physical or digital plot was captured for analysis.)
  • "Indicator-diagram analysis": The process of interpreting the shape and area of the diagram to evaluate work output, power loss, or mechanical faults.

    • Indicator-diagram analysis revealed a significant drop in compression pressure. (Studying the graph's features indicated a problem.)
Variants and Related Words
  • Indicator (n): a device that measures and displays data, such as pressure or temperature.
    • The pressure indicator showed a reading of 200 psi. (The measuring instrument gave a value.)
  • Diagram (n): a simplified drawing showing the appearance, structure, or workings of something.
    • The diagram of the electrical circuit helped identify the fault. (A schematic drawing was used.)
Synonyms
  • Pressure-volume diagram: a synonym emphasizing the two key variables plotted.
  • PV diagram: a common abbreviation for pressure-volume diagram.
  • Engine cycle plot: a broader term for any graph depicting engine cycle data.
Related Idioms
  • "Read the indicator-diagram": To interpret the meaning of the graph's shape and features.
    • The old mechanic could read the indicator-diagram like a book, spotting worn piston rings instantly. (He understood the graph's implications immediately.)