Frequent monitoring of soil and groundwater quality is traditionally a labor-intensive job. This is also the case if saltwater intrusion or contamination at remediation sites needs to be monitored. The Van Essen CTD-Diver sets the standard for reliability and longevity in groundwater monitoring. The CTD-Diver is a fully stand-alone sensor with built-in data logger and battery. The compact ceramic casing and sensor and unparalleled conductivity measuring range (0-120 mS/cm) make the CTD-Diver suitable for use at every measuring site.