You can also position probes with 10-micron accuracy in order to eliminate board distortion during test. Top-end flying probe systems allow better and reliable access by probing to within microns of the edge of component pads, or on vias. The systems can contact solder fillets away from the component itself. Test software allows you to program an offset, from 10 microns upwards, from the component CAD datum either globally or by individual component. This feature removes the need for manual intervention, although the software still allows you to do this during debug.
Component measurement is extremely good on top-end flying probers.
Think of trying to measure component values on a circuit board with hundreds of wires connected to it, each one providing stray capacitance. This is exactly the situation with a bed of nails connected to a board. A flying probe test avoids this situation and measures only the component. To enable you to make more connections between your test system and a board, some flying probers facilitate connections via edge connectors using a ZIF interface built into the test system. This facility also allows you to do double-sided testing using a simple bed of nails, which provides access only those networks inaccessible from the topside.