Part 2/5:
The HP 434 calorimetric barometer is capable of measuring power inputs from direct current (DC) to an impressive 12 gigahertz. The operation of this barometer hinges on a liquid that flows over a resistor. As power heats the resistor, the device measures the temperature rise of the fluid. This temperature differential is crucial for determining the power output, allowing for precise measurements even in scenarios where power transients are present.