Watts (p) are a measure of power or work. In an Ac circuit a watt is measured by multiplying Current times voltage times the cosine of the phase angle between current and voltage (P=ElcosΦ). DAE JOO's watt Transducers utilize solid state circuitry to provide high-accuracy and long term stability. A precision electronic multiplier allows measurement of true power to within 0.25% of Reading throughour a wide range of input voltage, current and power factor conditions.