With the injector testbench you have the ability to do a flow test at full or partial load. But it can also be very useful to see the actual spray pattern the injector is producing. I have already run some tests taking photo’s by hand. But it would be more reproducible to do it automatically.

So I changed the injectorbench software to include a mode to take photo’s. There is a possibility to use an additional trigger signal. I extended the bench to include the wiring for the extra trigger signal to a remote wire for my Canon 50D. The injector bench is separated from the camera by an optocoupler.

The setup now looks like this.

I used my 50mm prime lens on the camera and added to lights to be able to reduce the shutter time.

After a short debugging session on the software, it actually works :). You can specify the offset between the injector trigger signal and the time the camera is triggered. When running it looks like this.

And these are the photos of the injector.

The base idea seems to work ok, however it looks like the delay when the camera is triggered until it takes the picture is not constant. Because of this it is not possible to take accurate pictures of the spray pattern of the injector.

It is probably a better option to let the computer control a bright flash light to do a more accurate timing of the moment the picture is taken.