Vapor Quality Sensor - ATEX

Technical data: HBX-CR-IN / HBX-DX-IN 

The Vapor Quality Sensors have a new innovative technology which makes it possible to measure the mix between gas and liquid in a refrigerant from 0% gas to 100 % gas - a measurement no other sensor can provide. It consists of a tube, with metal inserts, where the mix of two phases pass through. The sensor measures the dielectric constant of the fluid, and as two different phases (liquid/gas) has different dielectric constant, the mix between the two, can be calculated. The output of the sensor is the “X” value which has a linear relation to the Volume % of liquid in the gas

The sensor offers very precise measurements and provides instant read-outs of the gas quality, making it useable in most evaporators (plate, pipe, and air evaporators).

All vapor quality sensors are suitable for controlling both DX, semi flooded and flooded operation.

Leakage detection for ammonia CO2 cascade systems
The vapor quality sensor can detect ammonia carbamate which is formed when CO2 leak into ammonia. The sensor can be used for both leakage detection and control an evaporator at the same time or just serve as leakage detector. The alarm can both be provided as a digital alarm and via the analog output. For shell and tube heat exchangers the HBAC is normally used.

The straight version called Inline is available from 1” to 2” and the sensor accepts flow in both directions. The pressure loss in the sensor is very low due to the straight flow and smooth internal design. Mounting can be both horizontal and vertical position. The sensor is made in stainless steel and can be butt welded (TIG) or brazed into the system.

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.

Product selection guide
To find the right part number to purchase please use our selection guide in the shop (link below), product overview under "ordering code" or send our Product Manager Henrik Kudsk a system description and he will guide you to the right part number. Please use the "Product Specification Form" (find it under the "downloads" tab on this product page) and e-mail it to   

Shop image

Product features

Measures the volumetric concentration of gas in a gas/liquid mixture
Balanced evaporator control to achieve semi-flooded operation with high heat transfer
Can be used to optimize and control both DX systems and overfeed systems
Instant measurement and analog output
Can be used for all common refrigerants


HBX DX Inline web


Connection Diagram

 Diagram sensor



Maal HBX Inline



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 degreeIP65
VibrationsIEC 68-2-6 (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

Pipe diameterDesignATEX/IECEx approvalOrdering code
DN 25 DX SystemsZone 0HBX-DX-IN-T-DN25-Z0
DN 40 DX SystemsZone 0HBX-DX-IN-T-DN40-Z0
DN 50 DX SystemsZone 0HBX-DX-IN-T-DN50-Z0
DN 25 Overfeed SystemsZone 0HBX-OVC-IN-T-DN25-Z0
DN 40 Overfeed SystemsZone 0HBX-OVC-IN-T-DN40-Z0
DN 50 Overfeed SystemsZone 0HBX-OVC-IN-T-DN50-Z0
DN 25 DX SystemsZone 1HBX-DX-IN-T-DN25-Z0
DN 40 DX SystemsZone 1HBX-DX-IN-T-DN40-Z0
DN 50 DX SystemsZone 1HBX-DX-IN-T-DN50-Z0
DN 25 Overfeed SystemsZone 1HBX-OVC-IN-T-DN25-Z0
DN 40 Overfeed SystemsZone 1HBX-OVC-IN-T-DN40-Z0
DN 50 Overfeed SystemsZone 1HBX-OVC-IN-T-DN50-Z0


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