0 past simple and past participle of preheat
1 to heat an oven to a particular temperature before putting food in it:
They also found that the observed expansion rates for preheated wires were essentially identical to wires that were not preheated.
The preheated case has a longer voltage pulse and lower current, a feature subsequently verified in similar tests with more accurate current and voltage monitors.
The left graph is the control target, the right the radiation preheated target.
These subsequent tests also found no measurable difference in any diagnostics between wires preheated for 30 minutes and wires preheated for 8-12 hours.
They found that when wires were preheated, the formation of detectable coronal plasma occurred faster, in accord with their singlewire results.
This shows indeed that if we have a material which is preheated but didn't expand, the shock velocity is practically the same as in the cold standard material.
Experiments in the low-current regime observed slightly improved core expansion rates for preheated wires, but this effect was not as large as that observed through the use of insulating layers.
Figs. 2 and 3 clearly show that the shock wave propagates in a preheated medium.