3.1 Name TWO devices that are used to test the hardness of a metal - NSC Mechanical Technology Fitting and Machining - Question 3 - 2017 - Paper 1

1. To check for worn cylinders, which can affect engine performance.
2. To determine the condition of piston rings and whether they're sealing properly.
3. To evaluate the integrity of valves and detect any leakage that could impact compression.

A tensile tester measures the resistance of a material to a static or slowly applied tensile axial force, allowing for the assessment of material strength and ductility.

1. A rich mixture setting which indicates that the fuel-to-air ratio is too high, leading to incomplete combustion.
2. An incorrect idle speed which can prevent the engine from operating efficiently, resulting in increased CO emissions.

1. Ensure that the measuring leads are inserted in the correct socket for the measurement being taken.
2. Set the multimeter to the desired function before taking measurements.
3. If uncertain of the expected measurement range, start with the highest range first to avoid damage.