Factory Direct · ISO 9001 · CE · UKCA · RoHS · ATEX · OEM/ODM Since 2019

Liquid Level Sensors
– Custom OEM
Manufacturer & Supplier

SEGMENsensor manufactures float switches, submersible transmitters, ultrasonic non-contact sensors, and coolant level sensors for CDU liquid-cooling systems. Custom output, housing, and private-label OEM from 10 pcs.

IP67 / IP68 Standard MOQ 10 pcs RFQ reply within 24 h
SEGMENsensor liquid level sensors – float switches and level transmitters

What is a Liquid Level Sensor?

A liquid level sensor detects or measures the level of a liquid inside a tank, vessel, or reservoir. SEGMENsensor manufactures five main types: magnetic float level switches for point detection, submersible hydrostatic transmitters for continuous 4-20mA measurement, ultrasonic non-contact sensors for corrosive or foam-laden liquids, capacitive level switches for conductive/non-conductive fluids, and coolant level sensors specifically designed for CDU data center liquid-cooling systems. All models are CE certified, IP67 rated, and available for OEM custom configuration.

Product Lineup

Liquid Level Sensors – 3 Core Series

Float switches to submersible transmitters — all OEM-configurable with custom cable, output, and housing material.

SEGMENsensor SFL series magnetic float level switch
Point-Level Detection
SFL Series — Magnetic Float Level Switch
Reed-chain or microswitch float level switches for single or multi-point detection in tanks. PP, PVDF, or 316L stainless steel housing. Vertical or horizontal mount.
Switch TypeReed switch / Microswitch / SSR
Contact Rating100 VA (reed) / 15 A (microswitch)
Temperature-40°C to +120°C (HT version up to +150°C)
ProtectionIP67 / IP68 (submersible float)
MaterialPP / PVDF / SUS 316L
SEGMENsensor SLS series submersible hydrostatic level transmitter 4-20mA
Continuous 4-20mA Measurement
SLS Series — Submersible Level Transmitter
Hydrostatic pressure-based continuous level transmitter. 4-20mA or 0-10V output, RS-485 Modbus optional. Suitable for wells, wastewater, and industrial tanks 0.5–200 m depth.
Range0–0.5 m to 0–200 m H₂O
Accuracy±0.1% FS to ±0.5% FS
Output4-20mA / 0-10V / RS-485
ProtectionIP68 (continuous submersion)
CablePUR / FEP, custom length
SEGMENsensor SEU series ultrasonic non-contact level sensor
Non-Contact Measurement
SEU Series — Ultrasonic Non-Contact Level Sensor
Top-mounted non-contact ultrasonic level sensor for corrosive liquids, foam, or open channels. IP67, 4-20mA + relay output. Blind zone from 25 cm, range up to 15 m.
Range0.25 m to 15 m
Accuracy±0.3% FS
Output4-20mA + 2× relay
DisplayLCD (optional)
ConnectionG¾ / G1 / flanged
Specifications

Technical Specifications Comparison

All models OEM-configurable. Contact us for ATEX, HART, or IO-Link variants.

Parameter SFL Float Switch SLS Submersible Transmitter SEU Ultrasonic
Measurement PrincipleMagnetic float + reed switchHydrostatic pressureUltrasonic transit-time
Measurement TypePoint level (ON/OFF)Continuous (analog)Continuous (analog)
RangeTank depth up to 10 m (multi-float rod)0.5 m – 200 m H₂O column0.25 m – 15 m
AccuracyN/A (switch)±0.1% to ±0.5% FS±0.3% FS
Output SignalRelay / SSR / 4-20mA (multi-float)4-20mA / 0-10V / RS-485 Modbus4-20mA / 0-10V / RS-485 / Relay
Supply VoltageAC 230V / DC 12–36VDC 12–36V (2-wire 4-20mA)DC 12–36V
IP RatingIP67 / IP68IP68 (continuous)IP67
Temp. Range (Liquid)-40°C to +120°C (HT: +150°C)-20°C to +80°C-20°C to +70°C (medium)
Housing MaterialPP / PVDF / SUS 316LSUS 316L / TitaniumABS / SUS 316L (probe)
Process ConnectionSide entry / top entry / flangedCable-suspended / threaded G½G¾ / G1 / flanged
Hazardous AreaATEX II 2G (option)ATEX II 2G (option)Safe area standard
CertificationsCE, RoHS, IP68CE, RoHS, IP68CE, RoHS, IP67
MOQ10 pcs10 pcs10 pcs
Lead Time2–3 weeks2–3 weeks3–4 weeks
Technology

How Liquid Level Sensors Work

Three proven measurement principles — choose by application, media, and accuracy requirement.

01
Magnetic Float Principle
A buoyant float rides on the liquid surface. As the liquid rises or falls, a permanent magnet inside the float moves past reed switches mounted on the sensor rod, triggering an electrical output. No power required for mechanical reed switch variants — ideal for simple high/low alarms in water tanks, chemical vessels, and coolant reservoirs.
02
Hydrostatic Pressure Principle
A submersible pressure sensor at the bottom of the tank measures the hydrostatic column pressure of the liquid above it. The pressure-to-level conversion is linear: Level (m) = Pressure (Pa) ÷ (ρ × g). A 4-20mA signal proportional to tank level is transmitted to PLC or SCADA systems. Accuracy to ±0.1% FS, unaffected by foam or vapor.
03
Ultrasonic Non-Contact Principle
An ultrasonic transducer emits a short acoustic pulse toward the liquid surface. The time-of-flight for the echo to return is measured and converted to a distance (level) reading. Since the sensor is mounted above the liquid with no contact, it works perfectly for corrosive acids, alkalis, slurries, and foam — including dielectric coolants in CDU systems.
H2-B — Tank Applications

Water Tank Level Sensor & Industrial Tank OEM Supply

From domestic water tanks to 50,000-litre industrial process vessels — SEGMENsensor supplies custom water tank level sensors and submersible level transmitters for OEM equipment builders worldwide.

Water Tank Level Sensor OEM

SEGMENsensor's float level switches and ultrasonic non-contact sensors are widely used as water tank level sensors in building water supply systems, cooling tower make-up tanks, rainwater harvesting tanks, and fire suppression reservoirs.

  • Vertical and horizontal float switches for single or multi-level detection
  • PP, 316L SS, PVDF wetted materials — suitable for clean water to mild chemicals
  • AC 230V or DC 12-24V supply, relay output for direct pump control
  • MOQ 10 pcs, custom cable length, private-label OEM packaging

Submersible Level Transmitter for Industrial Tanks

For continuous level measurement in industrial process tanks, our submersible level transmitter (SLS series) converts hydrostatic pressure to a 4-20mA signal linearly proportional to liquid depth. Suitable for 0.5 m to 200 m, in water, acids, alkalis, fuels, and slurries.

Pressure Range
0.1 bar – 100 bar
Output
4-20mA / RS-485
Accuracy
±0.1% to ±0.5% FS
Protection
IP68 continuous
Applications

Liquid Level Sensors for 8 Industry Segments

From oil & gas storage to data center liquid cooling — we specify the right sensor for your media and environment.

🛢️
Oil & Gas Storage
ATEX-certified float switches and submersible transmitters for crude oil, diesel, and condensate tanks. Stainless or titanium wetted parts.
💧
Water & Wastewater
IP68 submersible level transmitters for reservoirs, sewage lift stations, and flood monitoring wells. Cable lengths from 5 m to 100 m.
🧪
Chemical Plants
PVDF or PP float switches for HCl, H₂SO₄, and NaOH tanks. Non-contact ultrasonic sensors for fuming acids where metal contact is impossible.
🍺
Food & Beverage
316L SS float switches and submersible transmitters with FDA-compliant silicone seals for CIP tanks, fermentation vessels, and sirup storage.
💻
Data Center CDU Cooling
Coolant level sensors for CDU (Coolant Distribution Unit) reservoir monitoring in AI server liquid cooling. Non-contact, dielectric-fluid compatible. See CDU section below.
🏗️
HVAC & Building Services
Float level switches for cooling tower make-up water, chilled water tanks, and condensate pits. AC 230V relay output for direct integration with building management systems.
⚙️
Machine Tools & Hydraulics
Compact float switches for CNC machine coolant sumps, hydraulic oil tanks, and lubrication reservoirs. Side-entry or top-entry installation, custom cable gland.
🚢
Marine & Offshore
Stainless steel float switches and submersible transmitters for bilge monitoring, ballast tanks, and fuel tanks on vessels. IEC 60092 marine-grade wiring available.
CDU / Data Center Liquid Cooling

Coolant Level Sensor
for CDU — Data Center
Liquid Cooling Systems

As AI server racks exceed 100 kW per rack, direct liquid cooling via CDU (Coolant Distribution Unit) has become the standard. SEGMENsensor offers non-contact coolant level sensors designed for CDU reservoir monitoring — a globally underserved application with zero dedicated Chinese OEM sensor pages currently online.

  • Non-contact ultrasonic technology — no metal parts touching dielectric coolant fluid (PAG, PGW, deionized water)
  • Compatible with CDU reservoir materials: HDPE, polycarbonate, acrylic-window tanks
  • Low-level and high-level relay alarm output for automatic CDU pump protection
  • 4-20mA continuous level output for integration with rack management controllers (RMC)
  • Operating temperature: -10°C to +60°C (coolant side), matching CDU environment
  • Internal link: also see our CDU coolant flow meter for complete CDU liquid-loop monitoring
Request CDU Sensor Quote

CDU Coolant Level Sensor — Key Specifications

Measurement PrincipleUltrasonic non-contact
Sensing Range25 mm – 1,200 mm
Accuracy±1 mm (≤300 mm range)
Output4-20mA + 2× relay alarm
Media CompatibilityDielectric coolant, DI water, PAG, PGW
MountingTop-mount, G¾ thread or custom bracket
IP RatingIP67
Operating Temp.-10°C to +60°C
SupplyDC 12–24V
MOQ10 pcs (sample: 1 pc)
Lead Time3–4 weeks
CertificationsCE, RoHS

Custom bracket, cable, and connector available for OEM rack integration. NDA on request.

OEM Manufacturing

Liquid Level Sensor OEM Manufacturer — Factory Direct Since 2019

SEGMENsensor is a direct factory — not a trading company. Our Shenzhen facility has manufactured liquid level sensors since 2019, with dedicated R&D for float switches, hydrostatic transmitters, and ultrasonic sensors. We supply OEM equipment builders across oil & gas, water treatment, semiconductor, HVAC, and data center liquid cooling markets in 30+ countries.

Custom Material & Output

PP / PVDF / 316L SS / Hastelloy wetted parts. Output: 4-20mA, 0-10V, RS-485 Modbus, HART, IO-Link on request.

Private Label & OEM Packaging

Custom logo on housing, custom color, custom label insert. Private-label datasheet and box available from 50 pcs.

CE / RoHS / ATEX Documentation

Full CE Declaration of Conformity, RoHS certificate, and ATEX (II 2G Ex d) available for hazardous area OEM projects.

Fast Lead Time

Standard configurations ship in 2–3 weeks. Custom housing or output options 3–5 weeks. Expedited available for volume orders.

SEGMENsensor liquid level sensor OEM factory Shenzhen
Why SEGMENsensor

Factory Direct vs. Imported Brand Alternatives

Same IP67 rating and 4-20mA accuracy — at a fraction of the landed cost, with shorter lead times and direct engineering support.

Comparison Factor SEGMENsensor (Factory Direct) Imported Premium Brands
Manufacturing LocationShenzhen, China — direct factoryEurope / USA / Japan (resold in China)
MOQ10 pcs (samples: 1 pc)50–200 pcs standard
OEM CustomizationFull custom: housing, output, cable, labelLimited — catalog models only
Lead Time2–3 weeks standard6–14 weeks (import + distribution)
Price40–70% lower landed costHigh — brand premium + import duty
Engineering SupportDirect factory engineers, 24h RFQDistributor-mediated, slow NRE
CertificationsCE, RoHS, ATEX, ISO 9001:2015CE, ATEX (limited OEM documentation)
ATEX OptionAvailable on request (10 pcs MOQ)Usually available, high minimum
ISO 9001:2015
Quality management certified
CE Certified
EU Declaration of Conformity
ATEX Certified
Hazardous area Zone 1/21
RoHS Compliant
No restricted substances
Since 2019
20+ years sensor manufacturing
30+ Countries
200+ active OEM clients
FAQ

Frequently Asked Questions

Questions from OEM buyers about liquid level sensors, selection, and custom OEM orders.

What types of liquid level sensors does SEGMENsensor manufacture?
SEGMENsensor manufactures six types: magnetic float level switches (reed chain or microswitch), submersible hydrostatic pressure transmitters (4-20mA), ultrasonic non-contact level sensors, capacitive point-level switches, optical level switches for clear/opaque liquids, and coolant level sensors for CDU data center liquid cooling systems. All types are available in custom configurations.
What is a coolant level sensor for CDU (Coolant Distribution Unit)?
A CDU coolant level sensor monitors the coolant reservoir level in liquid-cooled data center rack systems. SEGMENsensor's coolant level sensors use non-contact ultrasonic or optical technology to detect low-coolant conditions without metal parts touching the dielectric fluid, ensuring safe operation of CDU systems for AI servers and high-density computing racks. Output: 4-20mA + relay alarm.
What is the minimum order quantity (MOQ) for OEM liquid level sensors?
The MOQ for standard OEM liquid level sensors is 10 pcs. Sample orders of 1–2 pcs are accepted for evaluation. Custom cable lengths, connector types, housing materials (PP, PVDF, 316L SS, Hastelloy), and private-label packaging are available from 50 pcs.
Can liquid level sensors be used in hazardous ATEX/IECEx zones?
Yes. SEGMENsensor offers ATEX-certified float level switches and submersible transmitters for Zone 1/Zone 2 and Zone 21/Zone 22 hazardous areas. These are used in oil tank farms, chemical reactors, and fuel storage. Certifications include ATEX II 2G Ex d IIC T6 Gb and IECEx on request.
What is the accuracy of submersible hydrostatic level transmitters?
SEGMENsensor submersible level transmitters achieve ±0.1% FS to ±0.5% FS accuracy depending on the model and pressure range (0.1 bar to 100 bar). The 4-20mA output is temperature-compensated over -20°C to +80°C. Long-term stability is ≤±0.1% FS per year.
How do I choose between float, ultrasonic, and submersible level sensors?
Choose float switches for simple high/low point detection (low cost, no power required for mechanical type). Choose ultrasonic non-contact sensors when the liquid is corrosive, has foam, or must not be touched. Choose submersible hydrostatic transmitters for continuous level measurement in deep tanks (0.5 m to 200 m depth), slurries, or wastewater where non-contact methods are impractical.
What output signals are available for continuous level transmitters?
Standard output options include 4-20mA (2-wire), 0-10V (3-wire), 4-20mA + RS-485 Modbus RTU, HART (on request), and IO-Link. Relay output is available for float and optical switch types. Custom outputs for OEM integration are supported.
What non-contact level sensor works for a coolant reservoir?
For coolant reservoirs — especially in CDU liquid-cooling systems and CNC machine sumps — SEGMENsensor recommends our SEU ultrasonic non-contact level sensor or optical point-level switch. Both avoid metal contact with the dielectric coolant fluid (PAG, PGW, deionized water), preventing contamination. The ultrasonic sensor provides continuous 4-20mA level output + relay alarm; the optical switch gives a clean dry-contact ON/OFF signal for low-coolant shutdown. Both are IP67 rated and CE certified.
Is there an IP67 level sensor available from a China factory with low MOQ?
Yes. All SEGMENsensor liquid level sensors are IP67 or IP68 rated as standard — not as an option. Our Shenzhen factory (Registration No. 91440300MAEUXXQU04) manufactures and ships IP67 level sensors from MOQ 10 pcs with CE and RoHS documentation included. Sample orders of 1–2 pcs are accepted. Full IP68 submersible transmitters (continuous immersion) are also available from 10 pcs. RFQ response within 24 hours.
What is the lead time for custom OEM liquid level sensor orders?
Standard configurations ship in 2–3 weeks. Custom cable, connector, or housing material options require 3–5 weeks. Full OEM private-label (custom housing mold, PCB, label) requires 8–12 weeks for first run. Expedited production is available for volume orders.

Related Articles

Float Level Switch Selection Guide: 5 Key Factors

Ready to Source Liquid Level Sensors Direct from Factory?

Tell us your media, tank size, required output, and IP rating — our engineers will specify the right model and send a quote within 24 hours.

Request a Quote for Liquid Level Sensors

Tell us your specification — our engineers reply within 24 hours.

MOQ 10 pcs · samples in 5–7 days · info@segmensensor.com

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