The device for measuring the current or emf is connected within the circuit of the thermocouple. It measures the amount of emf flowing through the circuit due to the two junctions of the two dissimilar metals maintained at different temperatures. In figure 2 the two junctions of the thermocouple and the device used for measurement of emf (potentiometer) are shown.
I think that this is what advertisers are shooting for when they pay the big price to get their ads up there. Regular billboards are just as effective as ever, even though there are now digital billboards being made that can have multiple ads on them and switch between them every few seconds.
These New Billboards Talk To Your Smartphone. For todayâs marketers, plain old visual outdoor advertising just isnât enough. Clear Channel Outdoor, one of the worldâs largest advertising companies, has a vision: smart billboards enabled with NFC and QR codes that beam content to the phones of passersby with a bump or even perhaps just a nod.