Do Calibration Stickers have to be visible?

Do the calibration stickers have to be visible? The calibration company puts the sticker underneath the scale.  

In my travels I am only aware of three counties that require the sticker to visible - all of which were in IL.

As soon as they're ON - it doesn't matter visible or not.

Hi,

for Europe it would say yes. It does not make sense to stick the label on the bottom of a scale, because you have to lift a device that otherwise has to stand exactly aligned, but under no circumstances should you tilt it. 

So, if visible everbody (during the daily checks with a test weight  and every user) can easily check, that the scale is ok und not only the guys from test equiment management.

More general: In some sensitive areas it makes sense to put additionally a GO/NO-GO (red/green) sign on the front. Each evening test equipments are set to red and will become green again after the daily check (test weight, pH buffer etc) has passed successfully. Otherwise in will stay on red until failure has been removed. So nobody will use an equipment not fit for application.

Rgds

mosktio