Newbury Park-based Electronic Sensor Technology Inc., a homeland security solutions provider, has announced a major order from New Jersey-based Sound and Optics International, Inc., valued at more than $3 million, for the company’s zNose, an electronic sensor device that can capture and analyze nearly any odor, fragrance or chemical vapor within 10 seconds. The devices are expected to be used by United Kingdom-based International Security Systems Ltd. for security applications. The order increases the company’s backlog to nearly $5 million. It came less than 10 days after the company was awarded a $1.25 million order for zNose units from Beijing R & D; technology based in China.