Hi Martin,

I missed your other post.

The clamp is a piezo thing that detects the pressure pulse in the hard line=pressure peak just before the injector pops.
The book says that the clamp should be close to the IP, ground is connected on the hard line nut on the delivery valve.
The strobe can be retarded or advanced to spot TDC on the pulley and you can read the timing on the display.
I also have a cable that is plugged into the rpm amplifier of my SD (where the TDC signal is provided) and I see more or less the same deg timing on the display.
I usually test at idle and check the timing device is working at all by increasing the rpm.
Even more accurate is using the signal of needle lift. Some BMWs have a needle lift sensor on cylinder 1 and the upper part of the injector can be used. I have to say that I was not able to adapt the mV signal to my AVL before I swapped the injectors again.
One deg delay shows up when you put the clamp near the IP compared to near the injector. This is hydraulic delay.
BUT, what you really want to "see" is start of combustion.
I am working on a super fast pressure sensor installed where the glow plug of cylinder 1 is and triggered with TDC notch of the pulley.
The deeper you go into this the more complex it gets.

There are cheaper strobe lamps but I had the chance to catch the AVL long time ago.
http://www.ebay.de/itm/Diesel-Zundlichtpistole-Stroboskoplampe-12-24-Volt-dig-/390154979843?pt=Elektroger%C3%A4te&hash=item5ad70c8a03

Tom