Brian Steinberg Senior TV EditorTelevisaUnivision is getting more entrenched in TV’s measurement wars.The Spanish-language media giant is teaming up with data company VideoAmp, one of a growing number of audience-measurement companies whose services are being tapped as TV networks mull alternatives to Nielsen, the industry’s de factor arbiter of audience size. Under terms of the pact, TelevisaUnivision will use VideoAmp’s data in a suite of advanced advertising solutions, giving advertisers a better sense of the viewers they are reaching and their responses to commercials.The company believes the agreement may help in its quest to draw a larger number of national advertisers to its client pool.