Submersible Level Transmitter — 4-20mA, IP68, OEM China Factory

The vented cable contains a thin breathing tube (usually PTFE or polyethylene) running from the sensor electronics compartment to the open air at the cable's connector end. This equalizes the pressure inside the sensor to atmospheric pressure, so the measurement reflects only the hydrostatic pressure of the liquid column — not changes in barometric pressure. Without venting, a rise in atmospheric pressure would register as a false level increase. Always keep the cable end vent open to atmosphere. SEGMENsensor includes a desiccant vent plug for outdoor installations.

Select a range where your expected level variation occupies 60–90% of full scale. For a 5 m deep tank with 0–4.5 m level range, choose a 5 mWC sensor. Using too large a range reduces resolution; too small a range risks over-ranging during filling surges. Common ranges SEGMENsensor stocks: 0–1, 0–2, 0–5, 0–10, 0–20, 0–40, 0–100 mWC. For liquids denser than water (e.g., brine, acid), the actual depth is less than the pressure equivalent — apply the specific gravity correction factor in your PLC/DCS program.

SEGMENsensor offers three wetted material configurations: (1) Ceramic (Al₂O₃) diaphragm + 316L SS housing — suitable for water, wastewater, mild chemicals, cooling fluids; (2) 316L SS diaphragm + 316L SS housing — for food-grade media, light hydrocarbons, mildly aggressive chemicals; (3) PVDF housing + PTFE-lined probe — for highly aggressive acids, alkalis, or solvents. Specify your process medium when requesting a quote. Never use ceramic diaphragm sensors in HF acid or strong caustic.

IP68 means the sensor is rated for continuous submersion beyond 1 meter (actual depth and duration are manufacturer-specified — SEGMENsensor rates our sensors to full working depth without time limit). This makes submersible level transmitters suitable for permanent installation in wells, boreholes, sumps, and tanks. The cable entry and connector joint are the most common failure points — ensure the M12 cable gland or flying lead exit is properly sealed with the supplied sealing compound or use our integrated cable version (no gland needed).

Yes. SEGMENsensor submersible level transmitters are used in CDU (Cooling Distribution Unit) coolant reservoirs for data center liquid cooling systems. The 316L SS probe and ceramic diaphragm are compatible with standard propylene glycol / water coolant mixtures (up to 50% PG). Specify the 0–1 mWC or 0–2 mWC range for typical CDU reservoir depths. Output 4-20mA connects directly to CDU controller cards. For CDU with deionized water loops, confirm probe material compatibility with your DI water resistivity requirements.

Standard output is 4-20mA (2-wire loop-powered). Connect the Brown wire (+) to PLC analog input (+), Blue wire (–) to analog input (–) with the PLC's internal 24V loop supply — or use an external 12–36V DC power supply with a 250Ω shunt resistor across the input to read 1–5V. For PLCs with 0-10V input cards, specify the 0-10V version (3-wire). Scaling: 4mA = 0% (empty), 20mA = 100% (full). SEGMENsensor can laser-mark the cable sheath with mA/level conversion tables for on-site reference.

MOQ is 10 pcs. Sample 1–2 pcs accepted for testing. CE Declaration of Conformity, RoHS declaration, and calibration certificate (optional) supplied with each order. Material certificates for 316L SS probe available on request. SEGMENsensor factory registration: 91440300MAEUXXQU04, Shenzhen, Guangdong, China. Typical production lead time: 2–3 weeks. Custom cable length, connector, range, output, and OEM labeling: add 1–2 weeks.