Resistors Watt rating : how to check it ?

[rephil]

Hi all,

In using a resistor we all are faced with its Watt rating. We normally use it with some safety margin as if 1 Watt is dissipated in it, the used resistor will be rated at much more in order to get a trustworthy circuit.

The problem I have now is related to the Watt rating of resistors that are sold on the net.

I have bought for cheap many 1% resistors that should be rated at ½ Watt as was told in the eBay auction. As I don’t see any difference with those that are rated at ¼ Watt already in my boxes at home (they look all the same way), I should like to know if there is a possibility to check that a resistor is rated at ¼ Watt or at ½ Watt. How do they proceed to check this rating in the industry ?

Please, consider that I am not allowed to ‘appreciate’ explosions, flames, fumes and the like in my lab as my family would not let me proceed with such a ‘dangerous’ hobby ... . So the check must be non destructive . .

Thank you for any help.

Best regards

rephil