Method 304 is the Resistance-Temperature Characteristic test to determine the percentage change in direct-current (DC) ohmic resistance from the DC ohmic resistance at the reference temperature, per unit temperature difference between the test temperature and the reference temperature.
The equation used to calculate this characteristic, commonly called the ‘temperature coefficient of resistance,’ establishes how a component’s resistance changes with temperature. The procedure involves measuring resistance at specified temperatures.
This test is important for resistors and other resistance-sensitive components used in military equipment where wide operating temperature ranges must be accommodated.