The most common radioactive product carried in a tanker is uranium hexafluoride. If I was under a tank of this, I would put four placards on it: radioactive, corrosive, dangerous when wet and inhalation hazard. Technically all you need is the first two, but you could put the other two on and still be okay.
The hazard class of the substance being carried
The placard on a tanker carrying hazardous materials will tell you the class of the hazard (flammable, explosive, corrosive, etc). If you have access to the North American Guide or a similar reference, the placard will also tell you something a bit more specific about the identity of the hazardous material - its category, or sometimes its chemical name.
Flammable placards must be posted on all sides of tanker transporting JP-8
the radiation can be measured because.........
The placard on the wall displayed the museum's latest exhibition information.
The word placard (noun meaning a sign, a notice, an advertisement) has no direct antonym; the closest would be 'without placard' or 'placard-less'.
A source of gamma radiation is placed on one side of the weld, and a photographic film is placed on the other. Bubbles and weak points will appear on the film.
In internal radiation therapy a source of radioactivity is surgically placed inside the body near the cancer
the placard have been posted everywhere.
placard means a poster for public display. Example: there was no placard outside.
Le placard (masc.) means the cupboard in English.
Hazmat haulers do. A food grade tanker, dry bulk tanker, water tanker, etc. would not.