How Does a Torque Meter Measure Engine Torque and RPM?

[Su Solberg]

I am going to measure the torque output of an diesel engine @ various RPM to understand the resistance of the gearbox connected.

I wonder is there any guides for Torque meter DIY and the basic principle of a torque meter that can measure RPM + torque.

Thanks in advence.

 

[FredGarvin]

Start reading through manufacturer's web sites. They are usually a wealth of information. Companies like LeBow are good starts. You also have to decide if you want a rotating or reaction meter. It sounds like you want a rotating one. All of the ones I have ever used did not have a speed signal output. That was measured separately.

They mostly operate on the idea of angle of twist of a shft inducing a phase change between separate windings.

Here's a good explanation of how the to torquemeters on the CH-47's engines (the T-55-L-712 in my day) works. Go down to the "Torquemeter Indicating System" section:
http://www.globalsecurity.org/military/library/policy/army/fm/1-506/Ch9.htm

Here's a start:
http://content.honeywell.com/sensing/sensotec/apnotes.asp?art=13

http://www.himmelstein.com/