Can a Tachometer Measure the Torque of a Rotating Disc?

[nicole2000]

Hello All!

I have one machine. The disc (Horizontal place) is rotating and connecting to the shaft which is connecting to gear box and ac motor.

I would like to k now the torque of rotating disc for some interval such as 10s, 20s, 30s, to take reading , but I do not have money to buy torque meter.


I would like to know can I use tachometer to take the rotation speed of rotating disc within interval, 10s per taking.
And then I can use T= I x aplha to find the different time's torque reading

Please advise me.
Or could you please give me another ideas or suggestions?
Thanks a lot.

 

[FredGarvin]

That's an extremely rough way to do it. If you were to go that route, I would recommend that you reduce that 10 sec interval to less than a second. If you can sample the speed quicker, say 10 Hz or better, you will have a better resultant calculation of the torque, especially if you are trying to see the result of an applied load.

Without proper instrumentation, I don't see how you're going to get any better results that easily.

 

[piercas]

Hello! Thank you for reaching out with your question about measuring the torque of a rotating disc. It is understandable that purchasing a torque meter may not be feasible for you at the moment. However, there are a few alternative methods you can use to approximate the torque of your rotating disc.

Firstly, using a tachometer to measure the rotation speed of the disc within a specific time interval is a good idea. As you mentioned, you can then use the formula T= I x alpha to calculate the torque, where I is the moment of inertia of the disc and alpha is the angular acceleration. However, this method may not be very accurate as it does not take into account external factors such as friction and air resistance.

Another method you can try is using a spring scale or a force gauge to measure the force required to stop the rotation of the disc. You can then use the formula T= r x F to calculate the torque, where r is the radius of the disc and F is the force measured by the scale or gauge. This method may provide a more accurate approximation of the torque, but it is important to keep in mind that it may still have some margin of error.

In addition, you can also try using a dynamometer, which is a device specifically designed to measure torque. While it may also require a financial investment, it is a more accurate and reliable method compared to the previous two.

Ultimately, the best way to accurately measure the torque of your rotating disc would be to invest in a torque meter. However, in the meantime, you can use one of the methods mentioned above to obtain a rough estimation of the torque. I hope this helps and I wish you all the best in your research!