Explain the Components of a rebound Hammer?

Several components of a rebound hammer are displayed in below Figure.

1. Concrete surface; 2. Impact spring; 3. Rider on guide rod; 4. Window and scale; 5. Hammer guide; 6. Release catch; 7. Compressive spring; 8. Locking button; 9. Housing; 10. Hammer mass; 11. Plunger

The rebound hammer correlates the rebound height of a spring driven mass after it impacts the surface of the concrete. The spring driven mass slides on a guide rod in the tubular housing. While the impact plunger is pressed tightly against the concrete surface, a trigger releases the spring-loaded mass causing it to impact the plunger and transfers the energy to the concrete surface. The mass after that rebounds and the rebound height is correlated to the surface hardness of the concrete. A common calibration chart relates the rebound number to the cube compressive strength for the underwater rebound hammer.