Product Overview
The WIKA-ST Deep Sea Submersible Differential transducer measures Δp at depth: a 17-4 PH stainless, environmentally sealed body rated for 6,000 psi of external case pressure, reading 0–200 to 0–5,000 psi differential with a bidirectional ±10 VDC output. Proof is 10,000 psi and burst above 15,000 psi, with a Seacon underwater connector available — the build for subsea and offshore differential monitoring where the sensor itself is submerged. Have a legacy tecsis part number for this measurement? Send it — WIKA acquired tecsis and now ships these under WIKA Sensor Technology, and we cross-reference the tecsis p/n to the current WIKA-ST equivalent at the same spec.
Key Features & Benefits
- The whole transducer goes to depth — this is not a topside sensor on long tubing — the environmentally sealed stainless body is designed to be submerged, with the case itself rated for the ambient pressure of deep water. Measure the difference where it exists, not at the end of a hose.
- Bidirectional output, zero at zero — the ±10 VDC output swings symmetrically around 0 V, so a reversing differential — flow that can run either way, a level that can invert — reads naturally without offset arithmetic. The sign of the reading is the direction of the difference.
- Subsea-serviceable connection — the Seacon underwater connector option lets the transducer mate and de-mate in the wet, and the body carries its full identification permanently. Built for installations you cannot walk up to.
Specifications
- Sensing principle
- Strain-gauge differential sensing in a fully submersible body — the transducer itself lives at depth, reading the difference between two sensing ports while the case carries the ambient sea pressure.
- Pressure type
- Differential (Δp), bidirectional — the output swings symmetrically either side of zero (e.g. −4,000 to +4,000 psid reads −10 to +10 VDC).
- Measuring range
- 0–200 to 0–5,000 psi differential; low ranges available.
- Accuracy
- Static accuracy 0.5% FSO (BFSL).
- Thermal effects
- Thermal effect <1.0% of FSO.
- Output signal
- ±10 VDC bidirectional (zero at 0 psid).
- Excitation / supply
- 22–35 VDC.
- Electrical connection
- Permanently identified (manufacturer, part and serial number, range, excitation, output, wiring code); available with a Seacon underwater connector.
- Wetted parts material
- 17-4 PH stainless steel wetted parts; 304 stainless header.
- Process connection
- Two sensing ports with counterbores for face-seal installation (Parker 2-010 O-ring).
- Overpressure / proof
- Proof 10,000 psi.
- Line (static) pressure
- External case pressure 6,000 psi (the datasheet’s feature rating extends to 10,000 psi external).
- Burst pressure
- Burst >15,000 psi.
- Compensated temperature
- +32 to +130°F.
- Approvals & certification
- Options: low ranges, Seacon connector, wide range of build options.
- Configuration & lead time
- Configured per the differential range, the depth (external case pressure), and the connector. Quote-only, no public price list.
Common Applications
- Subsea and offshore differential monitoring with the transducer at depth
- Reversing-flow and bidirectional Δp measurement (±range output)
- Submerged filter, screen, and intake condition monitoring
- Marine and underwater test installations needing a wet-mate connector
Design & Selection Considerations
- Depth is a spec of its own — rate the case, not just the ports — a submersible differential carries three pressures: the Δp it reads, the proof rating of the sensing ports, and the ambient case pressure of the depth it lives at. Use the input form to give us the deployment depth explicitly — the case rating, not the measuring range, is what the ocean tests. The spec that fails at depth is the one nobody wrote down.
- Plan the electrical run for the wet environment — the output is ±10 VDC on 22–35 VDC supply, so the cable run and the topside receiver must handle a bipolar voltage signal; specify the Seacon connector at order if the installation needs wet-mate service. The connector choice is permanent once the unit is down.
- FSO accuracy is a percentage of the range, not the reading — a ±0.25% FSO transducer rated for the full scale can be off by that fraction of full scale anywhere in its range — a larger relative error down at the low end. Size so the working pressure lands in the upper part of the range, and when you compare two sensors make sure both quote accuracy the same way. An oversized range quietly throws away resolution at the pressure you actually run.
- Respect the overpressure limit — the danger zone is below burst — proof / safe-overpressure is the pressure the sensor can see without losing calibration; burst is where it is destroyed. A unit driven past proof but short of burst keeps reporting plausible, wrong numbers. Size for the real worst case — including transients — and recalibrate after any suspected overpressure event. A spike that shifts calibration leaves no visible mark; the reading just drifts.
- Match the wetted material to the medium — the wetted parts see the process chemistry directly; the standard stainless suits most service, but corrosive, high-purity, or sour media want the right alloy specified up front. Use the input form to tell us the medium and we pick the wetted material to it. The wrong wetted alloy fails slowly and silently, not all at once.
To spec the right WIKA-ST submersible differential transducer:
To size and select the right transducer, send us: the pressure range and whether it is gauge, absolute, sealed, or differential; for a differential measurement, the maximum line (static) pressure as well as the differential range; the accuracy class you need (standard industrial vs. high-accuracy); the output the receiving device expects (4–20 mA, 0–5 V, 0–10 V, or raw mV/V) and the cable run; the process medium and temperature (so the wetted material and any extended temperature compensation are right); the process connection and electrical termination; and any area classification or agency approval (Ex / intrinsic safety, CSA, FM) and NACE / sour-service material requirement. For a fast transient, give us the rise time or frequency of the event so the natural frequency is sized above it.
Force & Pressure Application Sheet ›Talk to an engineer directly — Scott Prater, Principal · 917-580-0878 · scott@pratertechnical.com
Specifications compiled by Prater Technical Partners from WIKA product datasheets.