The 4410A is a wattmeter from Bird. A Wattmeter is an instrument for measuring the electric power (or the supply rate of electrical energy) in watts of any given circuit. Electromagnetic wattmeters are used for measurement of utility frequency and audio frequency power; other types are required for radio frequency measurements.
The 4410A high-sensitivity wattmeter is a solid choice for field-service applications where the greater dynamic range of the plug-in elements substantially reduce the number of elements needed to cover multiple power and frequency ranges. It is also well-suited to laboratory work where power levels as low as 2 milliwatts must be measured with high accuracy.
Each 4410A wattmeter plug-in element is capable of reading seven different power ranges cover 0.002 to 10,000 watts. The power ranges of the different elements overlap and include: 0.002–10 W, 0.02–100 W, 0.2–1000 W and 2–10,000 W. All ranges are in frequency bands from 200 kHz to 2300 MHz. Any one of the seven power ranges is selected by a rotary switch located on the front of the wattmeter. Forward and reflected power measurements are accomplished by rotating the element.
Exceptional ±5% of reading accuracy is achieved via a built-in temperature compensation circuit. This stated accuracy applies from 100% of full scale down to 20% of full scale across all seven ranges.