The International Open Source Hydrogen On Demand Builders Network.
Working on a small engine test bed shown in the photo. Top left shows a small gas engine bolted to a wooden plank. An ordinary automotive alternator is used to apply load. There is a fiber optic pressure sensor installed in the cylinder head. (The fiber optic cable comes out of holes drilled through the cooling fins. Shown on the bottom left.) It will go up to 3000 psi at 750 deg. F. Also, a trigger disk is bolted to the pulley on the shaft of the engine. (Shown in lower right hand picture) A variable reluctance sensor with its tip about 1-2 mm away from the trigger disk tooth clearance provides an input to track the position of the crank, Eventually an electronic module will process data from these two inputs to calculate indicated mean effective pressure (imep) in real-time. That will provide a measurement of load on the engine. For now, I have a digital oscilloscope that can store waveforms. In a week or so, I hope to create my first indicator diagrams. Lots more work left to be done.