Geotech Absolute Submersible Pressure Transducer
A sealed submersible pressure transducer for continuous liquid level measurement and pump control, with no vent tube to maintain. The sensor reads absolute pressure — water column plus atmosphere — so you subtract barometric pressure in software, typically from a barologger or a local weather record.Nothing about the vent can fail because there is no vent: no desiccant to change, no bellows, no moisture path into the cable. That makes absolute the better choice for long unattended deployments, deep wells, and anywhere site visits are expensive.All wetted parts are 316 stainless steel on a 0.72" (1.8 cm) body, and every unit is 100% computer tested and calibrated before it ships.Choose your configuration — 3 steps Output. 4–20 mA for pump controllers, PLCs and current-input dataloggers. Modbus RS485 + Temperature adds a temperature channel and digital addressing, for telemetry and multi-sensor strings. Pressure range. 0–30 through 0–1500 PSIA. Remember that roughly 14.7 PSI of any absolute range is consumed by atmosphere before the sensor is even wet, and 1 PSI ≈ 2.31 ft of water — so 0–30 PSIA leaves about 35 ft of usable submergence. Size to expected submergence plus atmosphere. Cable length. 25 to 500 ft in 25 ft increments, and the price you see includes it. Non-vented polyurethane cable is fitted automatically, so you always get the sealed absolute cable rather than the vented gauged part. Measure from the sensor to your termination point and add slack for the wellhead and enclosure; running short is the most common ordering mistake. Choose No cable if you already have a run, or need a length beyond 500 ft — worth noting on the deeper ranges, where 0–1500 PSIA reaches well past a 500 ft cable. Absolute or gauged? Absolute (this transducer) — sealed, maintenance-free, ranges to 0–1500 PSIA. Requires barometric correction in post-processing. Gauged — vented cable compensates for barometric pressure at the sensor, so the reading is true depth of water with no correction. The vent needs desiccant or bellows protection. Every absolute order needs these — please specify A cable spool for any run over 150 ft. Small to 350 ft, medium to 800 ft, large to 2500 ft. Calibration — 0.25% of full scale is standard and included; 0.1% is available as an upgrade. Surge suppression (recommended) — downwell or upwell, matched to your output type. Barometric reference. Absolute readings are only as good as the barometric record you correct them against — plan for a barologger or a nearby station. All of the above are in Geotech Pressure Transducer Parts & Accessories. Cable is included in your configuration above — the standalone cable listing covers replacements and custom lengths.Specifications Static accuracy 0.25% FS (0.1% optional) · non-linearity 0.07% FS · repeatability 0.015% FS Response time 2 ms Supply 12–36 VDC, 25 mA self-limited Operating −40 to 257°F (−40 to 125°C); compensated −4 to 185°F (−20 to 85°C); temperature accuracy ±0.5°C nominal Body 0.72" (1.8 cm) diameter, 4.3 oz (122 g), 316 stainless wetted parts, 1/4" NPT process fitting Cable jacket polyurethane, 0.335–0.360" diameter ApplicationsGroundwater and surface water monitoring, well and wetland studies, aquifer and pump testing, remediation and landfill pump control, and fluid level control — particularly long-term installations where a vented sensor would need servicing.Documentation Pressure Transducers — specifications (PDF) Submersible Pressure Transducer — installation and operation manual (PDF) Need a range that isn't listed? Select the next higher range and add your calibration instructions to the order, or contact us — special calibrations are routine and we build these in Denver.