Oil Level Sensor

Technical data: HBLC-OIL 

HBLC-OIL capacitive liquid level sensors are used to measure oil levels in industrial systems. The sensor transmits a current signal from 4 to 20 mA (4 mA when the transmitter does not register liquid - and 20 mA when the entire transmitter is surrounded by liquid).HBLC-OIL capacitive liquid level sensors are used to measure liquid levels in tanks and vessels. 

The sensor is designed in stainless steel and can be used in corrosive environments. The sensor must be supplied with 24 V DC through an Ex-barrier, which must be an approved and certifided galvanically isolated interface barrier placed outside the hazardous area. The sensor is a 2-wire design with analog output with 4 mA (empti tank) and 20 mA (full tank). The analog output shall be connected to the Ex-barrier. The Ex-barrier is not sccope of supply.  

The sensor can be set-up for liquid type in the HB-Tool which can be downloaded from our web-page. See HB-Tool. Diagnostic is as well a possibility with the tool. The programming must be carried out in an non hazardous area. 

The sensor range include sensors for zone 0 and 1 according to ATEX/IECEx. The sensors can be used in device category 1G and temperature class T1...T6.   

A 5 m cable with M12 plug type IEC61076-2-101 is included. 


Product features

  • Temperature range: -40...+70°C.
  • Max pressure: 150 bar
  • ATEX / IECEx: Ex ia  IIC T1…T6 Ga (Ta = -40°C to +70°C) 
  • Excellent liquid and gas compatibility 
  • Cost effective alternative to ultrasonic & radar sensor technologies 
  • Works with reflective liquids 
  • Will not fail due to vapor 
  • No galvanic corrosion
  • Split design which makes it easy to install and make diagnostic. 



  • Process plants
  • Storage tanks

Intrinsically Safe design:

Intrinsically Safe (IS) sensors are designed and wired to work on such a low current and voltage that it cannot possibly ignite flammable material. By limiting the energy available within the defined hazardous area, electrical equipment can operate safely even amid hazardous mixtures of gasses.

The HBLC sensor is designed for many kinds of liquidsbased on the dielectric constant. The liquid type is selected in the HB-Tool. 

The measuring principle and the influence of the dielectric constant:

Capacitors are designed with minimum two conductors, where one of them is electric isolated. The dielectric constant are key for operation of capacitors, the capacity size is measured in pF.

Dielectric constant (Relative permittivity) is a unique value on a scale of 1 to 100. The value can be seen as a media’s DNA, because it`s unique and related to the molecular structure and polarization.

The Dielectric Constant is always greater than or equal to 1. The larger the dielectric constant, the more charge can be stored (like a battery).

The dielectric constant changes with temperature and pressure, the sensor comes with automatic temperature compensation calibrated/adapted to the measured media.

Type of sensors:

Sensor type                Liquid type                                                                                                   Dielectric constant

HBLC-CO2                CO2(R744), Butane (R600), Isobutane (R600A), Propane (R290)             1.5-2.0
HBLC-OIL                  PAO oil, Mineral oil, POE oil, PAG oil                                                          2.0-4.0
HBLC-HFC                R507, R410a, R407c, R404a, R22, R32, R134a, R1234yf, R1234ze         4.0-10.0
HBLT-A2                    NH3, Water, R717, R718, Alchohol                                                             10.0-80.0



Connection diagram

Diagram sensor



Thread: 1" BSPP

HBLT A2 ex

Thread: 3/4" NPT

 HBLT A2U ex

Power supply
Voltage12-28 V DC two wire
Max. current consumption Max 20 mA
Plug connectionsM12, 5 pins - DIN 0627
Signal output 4...20 mA (AO)
Mechanical specifications
Material liquid partsAISI 304 / PTFE
Material electronic partsNylon 6 (PA)
Environmental conditions
Max pressure150 bar
Protection degreeIP66
VibrationsIEC 60068-2-6 (4g)
EMCEN 61000
Ex area
IECEx classificationEx ia IIC T1…T6 Ga
Device category1G for Zone 0 & 1
Type of protectionia
Gas resp. gas groupIIC
Temperature classT1….T6
Ambient temperature-40...+50°C/+70°C
When used in Ex-area the installation has to be carried out according to standards in force for the country in question.
The Equipment must be installed via an approved and certified galvanically interface barrier placed outside the hazardous area.

Ordering code

LengthThread typeATEX/IECEx approvalOrdering code
200 mm3/4” NPTZone 0 & 1HBLC-OIL-2-2-EX
200 mm3/4” BSPPZone 0 & 1HBLC-OIL-2-6-EX
300 mm3/4” NPTZone 0 & 1HBLC-OIL-3-2-EX
300 mm3/4” BSPPZone 0 & 1HBLC-OIL-3-6-EX
400 mm3/4” NPTZone 0 & 1HBLC-OIL-4-2-EX
400 mm3/4” BSPPZone 0 & 1HBLC-OIL-4-6-EX
500 mm3/4” NPTZone 0 & 1HBLC-OIL-5-2-EX
500 mm3/4” BSPPZone 0 & 1HBLC-OIL-5-6-EX
600 mm3/4” NPTZone 0 & 1HBLC-OIL-6-2-EX
600 mm3/4” BSPPZone 0 & 1HBLC-OIL-6-6-EX
700 mm3/4” NPTZone 0 & 1HBLC-OIL-7-2-EX
700 mm3/4” BSPPZone 0 & 1HBLC-OIL-7-6-EX
800 mm3/4” NPTZone 0 & 1HBLC-OIL-8-2-EX
800 mm3/4” BSPPZone 0 & 1HBLC-OIL-8-6-EX
900 mm3/4” NPTZone 0 & 1HBLC-OIL-9-2-EX
900 mm3/4” BSPPZone 0 & 1HBLC-OIL-9-6-EX
1000 mm3/4” NPTZone 0 & 1HBLC-OIL-10-2-EX
1000 mm3/4” BSPPZone 0 & 1HBLC-OIL-10-6-EX
1100 mm3/4” NPTZone 0 & 1HBLC-OIL-11-2-EX
1100 mm3/4” BSPPZone 0 & 1HBLC-OIL-11-6-EX
1200 mm3/4” NPTZone 0 & 1HBLC-OIL-12-2-EX
1200 mm3/4” BSPPZone 0 & 1HBLC-OIL-12-6-EX
1300 mm3/4” NPTZone 0 & 1HBLC-OIL-13-2-EX
1300 mm3/4” BSPPZone 0 & 1HBLC-OIL-13-6-EX
1400 mm3/4” NPTZone 0 & 1HBLC-OIL-14-2-EX
1400 mm3/4” BSPPZone 0 & 1HBLC-OIL-14-6-EX
1500 mm3/4” NPTZone 0 & 1HBLC-OIL-15-2-EX
1500 mm3/4” BSPPZone 0 & 1HBLC-OIL-15-6-EX
1700 mm3/4” NPTZone 0 & 1HBLC-OIL-17-2-EX
1700 mm3/4” BSPPZone 0 & 1HBLC-OIL-17-6-EX
2000 mm3/4” NPTZone 0 & 1HBLC-OIL-20-2-EX
2000 mm3/4” BSPPZone 0 & 1HBLC-OIL-20-6-EX
2500 mm3/4” NPTZone 0 & 1HBLC-OIL-25-2-EX
2500 mm3/4” BSPPZone 0 & 1HBLC-OIL-25-6-EX
3000 mm3/4” NPTZone 0 & 1HBLC-OIL-30-2-EX
3000 mm3/4” BSPPZone 0 & 1HBLC-OIL-30-6-EX