Van Essen Instruments is the world leader in groundwater monitoring technology. Our number 1 brand of Diver® products provide hydrogeology professionals with the tools they need to accurately collect data and reliably monitor groundwater conditions. For almost 20 years groundwater professionals, academia, and government agencies have used our groundwater monitoring technology to manage and protect water resources. We design and manufacture groundwater and surface water data acquisition technology, and our suite of Diver dataloggers monitor groundwater levels and temperatures. The CTD-Diver adds conductivity to these measurements. The Divers use stainless steel or ceramic materials to withstand brackish or salt environments. With the newly introduced Diver-NETZ family we offer a complete suite of products and services to monitor your network using high quality and highly reliable instrumentation. Our History Cornelis van Essen, an electronics engineer by profession established Van Essen Instruments in 1938 in Delft, Netherlands. Later, Cornelis developed an interest in instrumentation and his interests ranged from historical, to archaeological, and geological research. In the early 1990s, Van Essen began to offer standard water-related equipment such as standalone dataloggers, which used external sensors and flow meters for open channels. One of the first applications which used our standard equipment was for pumping tests for a Netherlands-based water company. Van Essen was also one of the first companies to develop a tide measuring system for the Rotterdam Harbor. This project used Telemetry, which was very advanced for its time and became a key milestone in Van Essen’s growth. Since the first Diver, Van Essen sold over 200,000 dataloggers worldwide. Our commitment to quality and performance has established Van Essen Instruments as one of the premier brands in the industry.