IP68 pressure transmitters which are waterproof rated for permanent installations underwater or requiring temporary flood protection. IP68 pressure transmitters are fitted with watertight cable connections in the form of a plug and socket or integral cable gland seal to prevent the ingress of water to a specified depth and time period.
IP68 pressure transmitters are specifically designed to deliver accurate and dependable pressure readings even when permanently submerged or subjected to significant flooding. These instruments feature robust, waterproof constructions with highly reliable cable entry seals or specialized underwater connectors, ensuring protection against water ingress to manufacturer-specified depths and durations. Critical for applications such as borehole level monitoring, wastewater management, marine systems, and infrastructure flood protection, understanding the specific sealing technologies, material compatibility, and appropriate cable configurations is key for engineers and technicians selecting these specialized transmitters.
Find out more about IP68 Pressure Transmitters to determine which product options and capabilities will best meet your application requirements.
IP68 rated pressure transmitters are engineered for continuous and reliable operation when fully submerged in water or other compatible liquids, or where equipment requires robust protection against temporary but significant flooding events. The IP68 designation itself signifies a high degree of protection against solid particle ingress (the ‘6’) and, crucially, protection against long periods of immersion under pressure (the ‘8’), with the specific depth and duration capabilities defined by the manufacturer. This performance level exceeds that of IP67, which typically only guarantees protection for temporary immersion up to 1 meter.
The construction of these transmitters prioritizes robust sealing and material integrity. Housings are commonly manufactured from corrosion-resistant materials such as 316L stainless steel, Duplex stainless steel for enhanced corrosion resistance in chloride-rich environments, or even titanium for particularly aggressive media or marine applications. Careful consideration is given to the wetted parts, including the sensing diaphragm, ensuring compatibility with the process fluid over extended exposure.
A critical design feature of any IP68 pressure transmitter is its electrical termination and cable assembly. Manufacturers employ meticulously engineered integral cable gland seals, often featuring double O-ring constructions or specialized potting compounds around the cable entry point to ensure a durable, watertight barrier. The cable itself is a key component, typically utilizing materials like Polyurethane (PUR) or Hytrel® for the outer jacket, which offer excellent resistance to water absorption, hydrolysis, and abrasion, preventing moisture wicking along the cable conductors. For applications requiring detachable connections, specialized IP68-rated underwater connectors, such as SubConn® or specific M-series variants designed for prolonged submersion, provide reliable field serviceability while maintaining the ingress protection integrity.
For gauge pressure measurement in submerged applications, maintaining an accurate atmospheric reference is paramount. This is often achieved through a vent tube integrated within the submersible cable. This tube allows the reference side of the sensing element to “breathe” with ambient atmospheric pressure changes, typically terminating in a dry, non-submerged location, often within a control cabinet equipped with a moisture-filtering vent. Without this venting mechanism, changes in barometric pressure or temperature-induced pressure changes within a sealed reference chamber could lead to significant measurement inaccuracies.
The “specified depth and time period” under the IP68 rating is a critical parameter that design engineers and instrument technicians must verify against their application requirements. Manufacturers will test and certify their transmitters for specific conditions, for example, continuous immersion at 100 meters water column, or operation at 500 meters for a defined number of hours. This rating directly impacts the mechanical design of the transmitter housing and the sealing system’s ability to withstand the hydrostatic pressure exerted by the surrounding liquid.
IP68 pressure transmitters are indispensable in a variety of demanding scenarios. They are routinely specified for level monitoring in boreholes, deep wells, and municipal water reservoirs, relying on hydrostatic pressure measurement. In wastewater treatment facilities, they monitor levels in tanks, sumps, and clarifiers. Marine applications include ballast tank monitoring on ships, draft measurement, and deployment in scientific buoys for oceanographic studies. Process engineers also utilize them in submerged chemical storage tanks or reactors where aggressive media may be present, necessitating careful selection of housing and diaphragm materials. Furthermore, they provide essential flood protection for critical instrumentation in utility vaults, underground infrastructure, and river monitoring stations, ensuring operational continuity even when submerged.
Installation practices for IP68 pressure transmitters require attention to detail to preserve their protective features. Adequate strain relief for the cable is essential to prevent stress on the gland seal or connector. Cables should be routed to avoid potential damage from abrasion, sharp objects, or even marine growth in long-term underwater deployments. Ensuring that any field-installable connectors are correctly assembled and tightened to the manufacturer’s torque specifications is vital for maintaining the IP68 seal throughout the instrument’s service life.