nothing
No
The 'one wattmeter method' can only be used for balanced, wye-connected, loads where the load's neutral point is accessible. The wattmeter's current coil is inserted into any line conductor, and the voltage coil is connected between the same line and the neutral point. The wattmeter reading indicates the power of one phase, so the total power is three times the wattmeter reading.To measure the total power of a balanced or unbalanced wye- or delta-connected load, it is only necessary to use twowattmeters -this is called the 'two wattmeter method'. In this case, the current coils of each wattmeter are inserted into any two line conductors, and the voltage coils are connected between the two line conductors and the third line conductor. The sum of the two wattmeter readings will indicate the total power of the load.
A wattmeter is designed so that it measures the supply voltage and the in-phase component of the load current. The product of these two quantities is the true power of the load.
The only type I am familiar with is the Bird 4391M. This a a digital display wattmeter whereas the Bird 43 is an analog (mechanical meter) device. The digital wattmeter has many functions available such as FWD PWR, RFL PWR, MOD, that are selected by front panel push buttons. It is a very versatile unit for measuring RF signal power. The one disadvantage to the digital wattmeter is that it needs to be powered to operate, either on AC line or the rechargeable battery pack. The Bird 43 wattmeter is a very simple unit to operate and requires no external power. You simply plug in the correct element, making sure the arrow on the element points in the same direction as the RF signal flow, apply the RF power and get the meter reading. With both types of wattmeters, the frequency and power range desired to be measured is determined by plug-in elements that go into the front panel of the unit. If using a Bird wattmeter, I would suggest using Bird elements. The ones made by Coaxial Dynamics are good, but the can sometimes cause calibration errors. I have calibrated the Bird wattmeters for many years and they are very durable. You may want to do an internet search on Bird wattmeters for more information on their particular functions. Hope this helps.
The advantages of wattmeter include adequate for low frequencies, easy to operate and better technology. There are different types of wattmeter and each has specific advantages.
nothing
No
Blondel's Theorem states that you can have one less wattmeter than there are conductors supplying a balanced or unbalanced load. In either case, the sum of the wattmeter readings will give you the total power of the load.
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JAMES WATT
Wattmeter is an intrument which is used to measure the power consumption of an Electric circuit or an appliance which is connected to the supply in terms of Watts.
It's cheaper.
There is no such thing as a 'low power-factor' wattmeter. A wattmeter always reads true power, regardless of the load's power factor.
Active volts amperes are measured by 2 wattmeter methods. A wattmeter will measure active power and not reactive power. Electrical engineering is a promising career for anyone who likes to generate power.
An energy meter measures power and time; a wattmeter measures an instantaneous value of power. Energy = Watt/seconds.
The voltage applied to the voltage coil of a wattmeter must not exceed the voltage rating of that coil.