All:

I have been around glow ducted fans for quite some time and I am familiar with 3KW electrics (pattern planes) but I am now venturing into the 4+ KW EDf systems

and I have some questions

about power measurement.

I have an Astro Flight watt meter that can measure up to 50 volts, 70 amps and about 5KW. I am moving from the 70 mm EDf's to the 90- 127 mm EDf systems. I tend to be a numbers guy and I am interested in testing some of the 90-127mm fans/power systems and I am willing to buy some equipment to do the testing. I can measure volts (have a fluke digital voltmeter) but I am curious as to how some of you measure current (amps) in excess of say 70 amps, voltages above 50 and power above 3KW.

Questions:

1. Are there some devices out there that some of you use to measure volts other than a dvm.

2. How do you measure amps (say in excess of 70 amps)? Do you use a clamp on meter?

3. Do you simply calculate the power using volts and amps or is there a meter out there that you use?

4. Are there any watt meters out there that you might recommend for current above about 125 amps, packs above 12s?

5. How do you measure efflux (exhaust velocity) and where do you tend to measure it (between the stators or at the back of the tail pipe)?

I do not mean to sound harsh but I am really interested in hearing from those that have actually performed these measurements (like Knife Liddle, Corsair Nut and many others).

Thanks in advance and I look forward to learing some new stuff about the larger EDF power systems.

Thanks,

Ed