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I wanted to test the Intertek Wattmeter basically to see how well it behaved with phase fired loads versus loads driven by a small Variac.
As you know, phase fired control devices of the type such as a light dimmer or other thyristor controller produce a chopped sine wave with the phase angle of firing controlled as opposed to a Variac which can generally produce a relatively clean sine wave of variable amplitude. I used a small 3 amp Variac for these tests. Excitation power was less than a watt.
To test the differences in actual power, as read by the Intertek, I used temperature as the final value in heating the surface of a 150 Watt clear incandescent lamp. I chose values at 25 Watt intervals and recorded temperature after settling, a lengthy procedure.
Ambient and bulb surface temperature were noted using a Fluke 52 dual thermometer and results corrected for ambient.
The test results show that the Intertek displays comparable (to a Variac) Watts, automatically corrected by power factor for the chopped light dimmer control device. (see attached spreadsheet)
Conclusion: The Intertek power monitor does a satisfactory job in displaying power in Watts when a light dimmer or other thyristor control device is operating into pure resistive load as compared to a more expensive Variac.
At around 16 USD and free shipping, it is a bargain for every FE researcher.
Note: Control devices, in each case, dimmer or Variac are placed on the output of the Intertek.
« Last Edit: 2013-02-14, 18:25:20 by ION »
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Topic: Testing Wattmeters (Read 1050 times)
