calculating motor power

[redlines]

I'm attempting to measure the output power of an air motor. I have measured torque in in*lbs, and speed in RPM. Power in Watts should be:

Watts = torque * rpm
= lb.in * rev/m * 44.25

My calculated numbers seem low. Am I missing something?

Thanks

 

[quark]

P(Watts) = T x w

Where, T = torque in N-m
w = angular velocity = 2 x Pi x N/60, where N is RPM.

So P = 2 x Pi x N x T/60

1 lb-in = 0.113 Nm

So P (watts) = 0.93 x T(lb-in) x N (RPM)

Regards,






Believe it or not : Though human body is made up of intricate and subtle mechanism, it is very poor in energy conversion. The maximum efficiency is 20% during cycling. During under water swimming it is just 4%.

 

[Metalguy]

OK, but if it was worse I could eat more.

 

[redlines]

Thanks, I was using rev/s instead of rad/s