Non-Linear Systems in Grantville manufactures and services electronic test instruments from Suite F at 4561 Mission Gorge Place in San Diego's 92120 ZIP. Founded in 1952 by MIT-trained engineer Andrew Kay, NLS developed the world's first digital voltmeter in February 1953, a breakthrough that replaced analog needle-based readouts with illuminated numerical displays. The company has built and sold over 1.5 million meters and instruments to more than 105,000 users across military, aerospace, and industrial sectors worldwide. Print and fulfillment for technical documentation, product catalogs, and shipping labels routes through Grantville providers including ZingPrint on the same commercial corridor. The current product catalog, now in its 25th edition, includes the NLS Series 8000 signal conditioners, PM Series AC and DC voltmeters, and custom-configured instrumentation for petroleum well acoustic production logging through parent company Linear Measurements, Inc., which acquired NLS as a wholly owned division in 1992. Grantville's Mission Gorge corridor supports a concentration of light-industrial and distribution operations, and NLS shares the 4561 Mission Gorge Place complex with other specialty manufacturers. The Mission Gorge Place address sits less than a mile south of the intersection where Mission Gorge Road channels traffic toward Mission Trails Regional Park, placing NLS in the commercial zone between SDSU to the west and the park entrance to the northeast. Kay's original NLS operation also spawned the Kaypro personal computer line in 1982, making this Grantville facility part of a lineage that contributed two foundational products to American electronics history. The lunch traffic from the industrial park feeds the Mission Gorge dining corridor, anchored by restaurants including Filippi's Pizza Grotto Mission Valley on the same stretch. NLS continues to distribute through authorized electronics suppliers across North America, Europe, and Asia.