I denna uppsats undersöker vi hur tre olika tidpunkter för visning av information på en secondscreen uppfattas av personer. Målet med undersökningen är att få en inblick i hur tittare upplever information som visas på en second-screen. Vi hoppas att resultatet ska kunna bidra till utformingen av kommande second-screenapplikationer. Dessutom har vi undersökt om tidpunkten av när information visas påverkar minnet av det personer ser på second-screenen. Vi utförde tester på totalt 18 personer med hjälp av tre stycken prototyper och varje testperson blev intervjuad efteråt..

Vattenfall and Svenska Kraftnät perform start-up tests, where hydropower generators are used to power up the electrical grid in case of a blackout. To monitor the electrical grid, Phasor Measurement Units (PMU) are used. Each PMU is individually equipped with a GPS-receiver to precisely timestamp the data relative to the official time UTC. During the test, it is also of interest to timestamp the measurement signals from individual hydropower generators to later compare with PMU-data, and thus study the power grids impact on the generator. The aim is to work out an appropriate method to make these measurements and to build a data acquisition system, capable of timestamp data relative to UTC, from a generator in one of Vattenfalls hydroelectric power stations. The problem is that the generator is located in an underground station which hampers the reception of GPS-signals and wiring should be avoided if possible. Time synchronization has been solved by using Vattenfalls network, which is synchronized by the network protocol NTP.