Measure build-up of hydrocarbons on water.

ID-225 Oil thickness sensor

mitigate risk of water pollution
minimal maintenance
early detection

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The LEAKWISE ID-225 Oil Thickness Sensor measures the thickness and monitors the buildup of hydrocarbons and other organic solvents on water.

There are two sub-models ID-225/100 & ID-225/200 for different maximum measured oil layer thicknesses: the ID-225 detects sheens as low as 1.0 mm and measures hydrocarbon thickness from 1-200 mm.

Many petroleum and power companies use the ID-225 for early detection, warning, and control of oil leaks and spills in the following applications:

  • Remediation control
    • Monitoring oil thickness changes over time in groundwater wells to enable effective oil removal methods
    • Monitoring effectiveness of remediation techniques
    • Implementing automatic on/off control
  • Skim tanks — The ID-225 is inserted into a tank through an inspection hatch, enabling automatic starting and stopping of skimming operation with pre-set thickness parameters.
  • Monitoring oil/water separators — An ID-225 can monitor oil layer thickness build up in the separator without human intervention.
  • Wastewater sewer monitoring — Installing an ID-225 in the sewer near the process area will detect and control hydrocarbon leaks at the source, reducing the load from the treatment plant and preventing spills.

The ID-225 Oil Thickness Sensor is used in conjunction with one of three controllers, depending on the application.

  • The PS-220 Controller is an analog signal processor and power supply in a NEMA 4 enclosure, and supports a single ID-220 Leakwise sensor.
  • The SLC-220 Digital Signal Processor for Multiple (2 / 4 standard, more in a network) ID-220 Series sensor support, with various output options, including relay, lights, 4-20 mA, LCD, Modbus in RS-232 and RS-485 communication, and cellular remote connectivity.
  • The WSP-220 Wireless communication – Point-to-Point data radio.



1 mm (0.04 in) 

Water level variation

Minimum: 30 cm (~12 in) (33 cm for ID-225/200) above well/tank/sump bottom

Maximum: 45 m (~150 ft)

Water lateral velocity

~20 cm/sec (~8 in/sec) when installed in a stilling well

Water temperature

0 to 70 °C (32 to 158° F); no freezing

Air temperature

-10 to 80° C (14 to 176° F)


Hydrocarbon resistant polymers, 316 stainless steel;

Integral cable

10 m (~33 ft.) supplied with sensor, additional length to order up to 50 m (164 ft) total




Oil monitoring range   

1 to 100 mm (0.4 to 4.0 in)

1 to 200 mm (0.4 to 8.0 in)


Ø 87 mm (3.43 in), height 150 mm (5.9 inch)

Ø 87 mm (3.43 in), height 300 mm (11.8 in)


ATEX Intrinsically Safe: II1G Ex ia IIC T4 Ga -40 °C to +70 °C. Also: IECEx and CETLUS

Combined with PS220/N4, approved for operation in hazardous location.


EPA - Conforms to Spill Prevention, Control and Countermeasure (SPCC) - Oil Pollution
Prevention regulation (40 CFR part 112), and EPA/530/UST-90/009 - Leak Detection Methods
TÜV - Type approval in accordance with WHG (Water Resources Law) § 19 h


ISO 9001:2015 Certified


Stilling well in 1 m & 2 m long sections, which can be assembled to any length 


Specifications vary for other sub-models - please enquire