Factory-direct magnetostrictive linear position sensors for OEM machine builders worldwide. SGM / SE series, 25–8000 mm, non-linearity <±0.01% FS, 4–20 mA, 0–10 V, RS485 and SSI outputs. In-cylinder models rated 35 MPa continuous. CE certified, IP67/IP68. OEM volume supply — quoted within 24 hours on working days.
A SEGMENsensor magnetostrictive position sensor measures absolute linear position without contact: a current pulse on a waveguide meets the field of a position magnet, and the travel time of the resulting torsional wave gives the position, with no homing at power-up. The SGM / SE range covers 25–8000 mm in rod, profile and in-cylinder designs.
How does a magnetostrictive sensor measure position without contact? Inside the stainless steel rod runs a thin waveguide wire. A ring magnet moves with the piston, the float, or the carriage. First, the electronics send a short current pulse along the wire. The pulse creates a circular magnetic field. Where that field meets the field of the magnet, the wire twists. This is the Wiedemann effect. The twist travels back to the head as a torsional wave, at about two thousand eight hundred metres per second, while a timer measures the travel time. Position equals wave speed times time. The result is absolute position, with no contact and no wear. SEGMENsensor magnetostrictive sensors cover strokes from twenty-five to eight thousand millimetres. Learn more at segmensensor.com.
Magnetostrictive position sensors: how SEGMENsensor builds and tests them. It starts with the electronics. Each sensor board is soldered by hand and fitted into the sensor head. The head, cable and connector are assembled on the housing, and heat-shrink sleeves seal the wiring. Rods and flanges are joined by laser welding on a rotary fixture, with a camera to align each seam. The electronics then run on a burn-in rack. Every sensor is tested. The oscilloscope checks the return signal, and a meter checks the output. Each sensor is then calibrated on a linear test bench, where software checks its reading along the stroke. Finally, the nameplate is laser-marked with the model and the company name. Strokes 25–8000 mm · OEM volume supply · Request a quote at segmensensor.com
Magnetostrictive position sensors: testing, calibration and marking. Electronics boards are aged on burn-in racks before assembly. Each sensor is then wired up for testing. The return signal is checked on an oscilloscope. On a linear test bench, the magnet moves along the rod, and the output is calibrated against its position. Calibration values are set and recorded in software. Finally, each nameplate is laser-marked with the model and the company details. Every sensor tested · OEM volume supply. Request a quote at segmensensor.com.
Every unit is tested before shipment. Photos from our own production and test lines.
Buying cylinder position sensors for India or Canada? See our India and Canada pages, or all export market pages.
What is a magnetostrictive position sensor? A magnetostrictive position sensor is a non-contact absolute linear position transducer based on the Wiedemann effect. A current pulse travels along a magnetostrictive waveguide; a position magnet on the moving part creates a torsional strain wave at the exact point of contact. The travel time of this wave determines absolute position — with no zeroing required at power-up. SEGMENsensor manufactures magnetostrictive sensors in Shenzhen, China, in the SGM / SE series covering 25 mm to 8000 mm, with 4-20mA, 0-10V, RS485 and SSI outputs.
Three families of SGM / SE part numbers: external profile and rod sensors, in-cylinder sensors, and liquid level sensors — all absolute, all non-contact, all CE certified.
Sensors mounted on the machine surface. SGM-PE10 is an aluminium-profile sensor for 25–8000 mm with slider or floating magnet and analog, RS485 or SSI output; SGM-PE20 is a slimmer profile for 25–4000 mm; SGM-PR20 has a stainless-steel head and rod sealed to IP68 for 25–7500 mm. See SGM-PE10, SGM-PE20 and SGM-PR20.
Rod sensors built into hydraulic cylinders; the pressure tube is rated 35 MPa continuous and 70 MPa peak. SGM-PR10 covers 25–8000 mm, SGM-PF10 has a flat disc head for limited space, SGM-PF20 an embedded Φ48 flange, SGM-PR40 and SGM-PR50 are compact and miniature heads for 25–4000 mm. SE-PR30 is the intrinsically safe version. See SGM-PR10, SGM-PF10, SGM-PF20, SGM-PR40, SGM-PR50 and SE-PR30.
SGM-LS10 (stainless rod, 25–8000 mm), SGM-LC10 (PP / PFA for acids and alkalis, 25–1000 mm) and SGM-LK10 (slim rod, 25–4000 mm) output analog or RS485. The flameproof SE-LX10 (strap-on for magnetic level indicators), SE-LX20 (rigid rod) and SE-LX30 (flexible cable) cover 200–8000 mm with a local display, 4–20 mA + HART (parameters settable with a HART handheld communicator), 0–10 V or RS485. See the level sensor overview.
Nine SGM / SE position series, each with its own page, full specifications, ordering code and two-page datasheet. SE marks the intrinsically safe version. OEM volume supply, samples in 5–7 working days.
| Part number | Best for | Range | Output | Protection | Datasheet |
|---|---|---|---|---|---|
| SGM-PR10 | Hydraulic cylinder position sensor | 25–8000 mm | 4–20 mA / 0–20 mA / 0–10 V / 0–5 V / RS485 / SSI | IP67 | |
| SGM-PE10 | Magnetostrictive linear position sensor | 25–8000 mm | 4–20 mA / 0–20 mA / 0–10 V / 0–5 V / RS485 / SSI | IP67 | |
| SGM-PR20 | IP68 magnetostrictive position sensor | 25–7500 mm | 4–20 mA / 0–20 mA / 0–10 V / 0–5 V / RS485 | IP68 | |
| SGM-PE20 | Slim linear position sensor | 25–4000 mm | 4–20 mA / 0–10 V / RS485 | IP67 | |
| SE-PR30 | Intrinsically safe linear position sensor | 25–4000 mm | 0.5–4.5 V / 0–5 V / 4–20 mA / RS485 | IP67 IP68 | |
| SGM-PF10 | Flat head magnetostrictive sensor | 25–8000 mm | 4–20 mA / 0–20 mA / 0–10 V / 0–5 V / RS485 | IP68 | |
| SGM-PF20 | Compact magnetostrictive sensor | 25–4000 mm | 4–20 mA / 0–10 V / 0.5–4.5 V / 0.25–4.75 V | IP68 | |
| SGM-PR40 | Compact rod position sensor | 25–4000 mm | 4–20 mA / 0–20 mA / 0–10 V / 0–5 V / RS485 | IP68 | |
| SGM-PR50 | Miniature linear position sensor | 25–4000 mm | 4–20 mA / 0–20 mA / 0–10 V / 0–5 V / RS485 | IP68 |
Values from the SGM / SE series datasheets, grouped by family — open the series page for the full table and ordering code. Quoted by model and quantity, within 24 hours on working days.
| Parameter | External profile / rod (SGM-PE10 · SGM-PE20 · SGM-PR20) | In-cylinder (SGM-PR10 · SGM-PF10 · SGM-PF20 · SGM-PR40 · SGM-PR50) | Liquid level (SGM-LS10 · SGM-LC10 · SGM-LK10 · SE-LX10/20/30) |
|---|---|---|---|
| Measuring Range | 25–8000 mm (PE10); 25–4000 mm (PE20); 25–7500 mm (PR20) | 25–8000 mm (PR10, PF10); 25–4000 mm (PF20, PR40, PR50) | 25–8000 mm (LS10); 25–1000 mm (LC10); 25–4000 mm (LK10); 200–8000 mm (SE-LX) |
| Resolution | 16-bit D/A (analog) | 16-bit D/A (analog) | 16-bit D/A (SGM); 1 mm or 0.1 mm (SE-LX) |
| Non-Linearity | <±0.01% FS (min ±50 µm) | <±0.01% FS (min ±50 µm) (PR10, PF10) | <±0.05% (LC10); ±1 mm (SE-LX) |
| Repeatability | <±0.001% FS (min ±5 µm) | <±0.001% (min ±5 µm) (PR10, PF10); ±0.005 mm (PF20, PR40, PR50) | ±0.005 mm (LS10, LK10); <±0.001% (min ±10 µm) (LC10); ±1 mm / ±0.1 mm (SE-LX) |
| Output Signals | 4–20 mA, 0–20 mA, 0–10 V (0–5 V on PR20), RS485 Modbus RTU; SSI on PE10 (on request on PR20) | 4–20 mA, 0–20 mA, 0–10 V, RS485 Modbus RTU; SSI on PR10 (on request on PF10) | 4–20 mA, 0–10 V, 0–5 V, RS485 Modbus RTU; SE-LX: 2-wire 4–20 mA + HART (parameters settable with a HART handheld communicator) |
| Supply Voltage | 24 V DC ±20% (standard; 12 V and 5 V ranges depending on output and model) | 24 V DC ±20% | 24 V DC |
| Operating Temp. | -40°C to +85°C | -40°C to +85°C | -40°C to +85°C; SE-LX rod -40~+250℃ (high-temperature version) |
| Pressure Rating | — (external mounting) | 35 MPa continuous, 70 MPa peak | — |
| Protection Rating | IP67 (PE10, PE20) / IP68 (PR20) | IP67 (PR10) / IP68 (PF10, PF20, PR40, PR50) | IP68 (SGM) / IP67 (SE-LX) |
| Housing | Aluminium profile (PE10, PE20); stainless steel (PR20) | Pressure-resistant rod with aluminium or compact head | Stainless rod (LS10, LK10); PP / PFA (LC10); flameproof housing with display (SE-LX) |
| Electrical Connection | Direct cable or connector | Direct cable or connector | Cable or connector (SGM); flameproof terminal housing (SE-LX) |
| Explosion Protection | — | SE-PR30 intrinsically safe version | SE-LX flameproof |
| Samples | 1–5 pcs, 5–7 working days | 1–5 pcs, 5–7 working days | 1–5 pcs, 5–7 working days |
| Lead Time | Confirmed with the quotation | Confirmed with the quotation | Confirmed with the quotation |
Magnetostrictive sensing (Wiedemann effect) delivers absolute position measurement with no moving contacts, so nothing wears in the measuring path.
A short electrical current pulse travels along the magnetostrictive waveguide wire at the speed of light, generating a circumferential magnetic field around the wire.
The permanent magnet on the moving part (the position float) interacts with the circumferential field at its exact location, inducing a torsional (twisting) mechanical strain in the waveguide at that single point.
The torsional strain wave propagates along the waveguide at the speed of sound. A magnetostrictive pickup at the end detects the wave's arrival time.
The time interval between the current pulse and the strain wave arrival is converted to absolute position by the internal ASIC. The result is output as 4-20mA, 0-10V, RS485 or SSI — absolute, not incremental.
Send us the stroke, output, connector and mounting thread of the installed sensor. We propose the matching SEGMENsensor model with its datasheet values; OEM volume supply, samples 1–5 pcs in 5–7 working days, production lead time confirmed with the quotation.
Replacing an installed sensor? Use the cross-reference by specification →
Tell us your current sensor's stroke, output type, and connector spec. We'll confirm compatibility and quote within 24 hours.
Magnetostrictive sensors excel wherever absolute position is required without incremental re-homing, and wherever high pressure or harsh environments eliminate contact-based alternatives.
SEGMENsensor has manufactured magnetostrictive position sensors since 2019. We are a direct factory — in-house waveguide processing, ASIC-based signal conditioning, and ISO 9001 calibration. No trading company. No distributor. Factory-direct pricing quoted by model and quantity within 24 hours.
Choose the right sensor for your OEM application. Magnetostrictive is the best choice for long strokes, absolute position, and hydraulic cylinder integration.
| Criterion | Magnetostrictive (SEGMENsensor) | LVDT | Linear Potentiometer | Linear Encoder |
|---|---|---|---|---|
| Absolute Position | ✓ Absolute — no re-homing | ✓ Absolute | ✓ Absolute | Incremental (needs homing) |
| Best Stroke Range | ✓ 25mm–8000mm | ±0.5mm–±500mm | 10mm–2000mm | Unlimited |
| Resolution | ✓ 16-bit D/A (analog) | ✓ Infinite (analog) | 0.01%–0.1% FS | 1–5µm |
| Hydraulic In-Cylinder | ✓ 35 MPa continuous | Not rated | Not suitable | Not suitable |
| Vibration Immunity | ✓ Excellent | ✓ Excellent | Poor (wiper bounce) | Moderate |
| OEM Cost (Factory) | Medium (quoted by model and quantity) | Low–Medium | ✓ Lowest | High |
In-house waveguide processing, PCB assembly, and calibration. Batch traceability on every order.
EMC and LVD directive compliance. CE declaration provided for EU customs clearance.
Intrinsically safe SE-PR30 and flameproof SE-LX level transmitters for oil, gas and chemical applications.
Engineering team with 20+ years of sensor experience. Direct factory — not a trading company.
Choose the mounting first — inside a hydraulic cylinder, outside on the machine frame, or in a tank — then the stroke and the output signal. The table maps nine common OEM applications to the SGM / SE series that SEGMENsensor builds for them; every series covers 25–8000 mm or a subset of it, and the level transmitters cover 200–8000 mm.
| Application | Recommended series | Range | Typical output | Why this series |
|---|---|---|---|---|
| Mobile hydraulic cylinders (cranes, excavators, presses) | SGM-PR10 / SGM-PF10 | 25–8000 mm | 4–20 mA / 0–10 V / RS485; SSI on SGM-PR10 | In-cylinder pressure tube, 35 MPa continuous / 70 MPa peak |
| Compact cylinders with limited end-cap space | SGM-PF20 / SGM-PR40 / SGM-PR50 | 25–4000 mm | 4–20 mA / 0–10 V; RS485 on SGM-PR40 / PR50; 0.5–4.5 V on SGM-PF20 | Short head, IP68 |
| Injection moulding and machine axes, external mounting | SGM-PE10 (profile) | 25–8000 mm | 4–20 mA / 0–10 V / RS485 / SSI | Profile housing with slider or floating magnet, IP67 |
| Space-limited external mounting | SGM-PE20 (slim profile) | 25–4000 mm | 4–20 mA / 0–10 V / RS485 | Slim housing, IP67 |
| Outdoor, wet or washdown machines | SGM-PR20 (rod) | 25–7500 mm | 4–20 mA / 0–20 mA / 0–10 V / 0–5 V / RS485 | IP68 rod sensor |
| Hazardous areas (position) | SE-PR30 (intrinsically safe) | 25–4000 mm | 0.5–4.5 V / 0–5 V / 4–20 mA / RS485 | Intrinsically safe design, IP67 / IP68 |
| Tank level — water, oils, stainless-compatible media | SGM-LS10 | 25–8000 mm | Analog or RS485 | Stainless rod, single or dual float |
| Tank level — acids and alkalis | SGM-LC10 | 25–1000 mm | Analog or RS485 | PP or PFA wetted rod |
| Process tanks needing flameproof housing and local display | SE-LX10 / SE-LX20 / SE-LX30 | 200–8000 mm | 4–20 mA + HART (parameters settable with a HART handheld communicator) / 0–10 V / RS485 | Strap-on, rigid rod or flexible cable versions |
A single SEGMENsensor rod covers 25–8000 mm (SGM-PR10, SGM-PE10, SGM-PF10, SGM-LS10). Compact series stop at 4000 mm, SGM-PR20 at 7500 mm and SGM-LC10 at 1000 mm. Non-linearity on the SGM-PR10 / PE10 family is <±0.01% FS and repeatability <±0.001% FS; the operating temperature is -40 °C to +85 °C.
Use 4–20 mA for long cable runs to a PLC, 0–10 V for short runs inside a control cabinet, RS485 Modbus RTU when several sensors share one bus, and SSI for closed-loop motion control (SGM-PR10 / SGM-PE10). The standard supply is 24 V DC; 12 V and 5 V supply ranges are available depending on output and model. For the measuring principle behind these numbers, read how a magnetostrictive position sensor works and what the Wiedemann effect is; for factory, testing and OEM terms, see choosing a magnetostrictive position sensor manufacturer and the hydraulic cylinder magnetostrictive sensor page.
Ranges, outputs, accuracy, wiring and ordering codes for the SGM / SE position series.
Download datasheet (PDF) More magnetostrictive datasheets by series →
Not sure which series fits? Send the stroke, mounting, output and supply voltage — our engineers reply within 24 hours. OEM volume supply, samples of 1–5 pcs ship in 5–7 working days. Request a quote
Common questions from OEM engineers. Email info@segmensensor.com for application-specific advice within 24 hours.
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Tell us your stroke, output type, operating pressure, and quantity. Engineering team replies within 24 hours.
SEGMEN (Shenzhen) Industrial Development Co., Ltd. · Shenzhen, China · info@segmensensor.com · +86 138 2870 4591