Suggestion of any Power Sensor

[barryforever]

Hello...
Im working on Fuel stack Hydrogen technology.I have designed a automated test
system in Labview. I m going to test Power Generation maximum output power for a particular pressure of hydrogen inflow..
I want to measure power directly a digital format like 4-20ma or 4-10Vdc ... so that i can feed it to the system directly so that the automatic system continues ...
So any suggestion of Power measurement Sensors

 

[sunderwood]

Voltage sensing can be done with a simple opamp circuit, either a voltage divider or a differential amplifier. For the current, you can either use a series resistor with a diff amplifier, or a hall sensor with proper scaling (opamps again)... It should be straightforward.

 

[kender]

The true power measurement sensor is a calorimeter. Run the output of your fuel cell into a resistor. Put resistor into a vessel with water, which is thermall insulated. Stir the water. Measure it's temperature.

Too awkward? Then do P=VI. Measure voltage and current into the load that the fuel cell is outputing to. Multiply in LabView.

 

[barryforever]

i need a more accurate method of measurement ..
I found these at ebay just tell me whether are adequate to measure power
**broken link removed**

 

[FvM]

The said power sensor is very different from what you need in your fuel cell application. I think the only suitable method is by mesauring current and voltage (as suggested) and calculating the power in digital processing. For AC (mains voltage) applications, digital instruments, also with a 4-20 mA output are available from electrical instrumentation manufacturers. May be you can get some for DC power also. You didn't mention the voltage and current range, that may be important to indentify a suitable instrument.

 

[kender]

i need a more accurate method of measurement

How accurate do you want your power measurement to be?
What are the ranges of voltage and current that you expect from your fuel cell?

 

[barryforever]

230 v and 10 amps

 

[kender]

230 v and 10 amps

Are you lookig for something similar to a power meter used by the utility companies?

 

[FvM]

I had understood, that a DC power meter is requested. If it's actually AC, you have a rich choice of ready to use components, from general electrical instrumentation and automation equipment as well. Some of these parts may be able to measure also DC power.

 

[kender]

I had understood, that a DC power meter is requested. ...

One thing in this thread that so far defies understanding is the fact that P=VI measurement was dismissed as insufficiently accurate.

 

[barryforever]

where can i get these things