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.
5 Most Common Advertising Techniques. A successful advertisement creates a desire in viewers, listeners or readers. It also provides information on how to fulfill that desire and makes the potential customer feel good about doing so. With so many products and service providers in the marketplace, using a proven technique in your advertising increases the likelihood that your ad dollars will return value. Basic techniques used in propaganda transfer successfully to advertising and remain the most frequently employed.