I stand corrected on my reply. AGNGA recommends testing away from vehicles and large vertical objects. Their training videos do not mention shoring however. I may direct this question directly to the gauge manufacturer.
The gauge's manual only mentions to not perform standard counts on top of a truck tailgate, or other non-solid material. I don't know that is has much to do with the metal itself. In certain scenarios with minimal space to do my standard counts and my compaction testing, I have parked my work...
I am updating my company's training manual for compaction testing protocols using a portable nuclear gauge and hope to see if anyone could help me get clarification on using the Trench Offset function. Will a metal trench shield/trench box affect the gauge readings? If so, can it be corrected...
