Multiple tests, and various testing, must be done to arrive at plausible results.
Also common is problematic results being thrown out because they are inconsistent with expected results.
Techniques include tree rings in timbers, radiocarbon dating of wood or bones, and trapped-charge dating methods such as thermoluminescence dating of glazed ceramics.
Also, the difficulty of using carbon dating increases as objects grow older.
Living things have concentrations of carbon-14 in them that are identical to the concentrations of carbon-14 in the atmosphere at the time they die.
This is a radiometric technique since it is based on radioactive decay.
Cosmic radiation entering the earth’s atmosphere produces carbon-14, and plants take in carbon-14 as they fix carbon dioxide.
So, an old spear can be tested at the wooden shaft, but not the sharp stone head.