Rod Style - Vapor Quality Sensor

Technical data: HBX-DX-R & HBX-CR-R

HB products has developed the unique vapor quality sensor, which is the only sensor able to directly measure the liquid content of liquid in the evaporator output. The sensor works both in pump circulated and DX systems and can optimize the efficiency and capacity to a new level.

Evaporator control
The optimal evaporator is not filled with liquid refrigerant like you often have in pump circulated refrigerant systems with circulation ratios above 1.5. The optimal evaporator is not dry like a lot of superheat-controlled evaporators.
By measuring the liquid content in the evaporator output and using this measurement to control the liquid feed.

Most refrigeration systems operate most of the time in part load and especially during part load the efficiency is typically rather poor and can be optimized significantly. Pump circulated systems fills the evaporator with liquid which reduce heat transfer by 50 % and increases the pressure loss which increase energy consumption. For pump circulated systems an energy saving of minimum 20% is typical for optimized systems, and much more on systems without circulation control.

In DX systems a larger part of the evaporator is used for superheating and the superheat is increased which reduce capacity and increase the power consumption dramatically. We have documentation showing an energy saving of 20% during full load and 50% during part load for a DX ammonia system. Link to the documentation.

Rod style version
The rod style sensor has been on the market for several years and works well if it is installed correctly. This sensor only measures the liquid inside the sensor element itself, and not like the other types between the inner element and the pipe walls. This means the sensor must be installed where the liquid flows at the bottom of a horizontal pipe. The sensor must be installed in an elbow with the sensor element located at the bottom of a horizontal pipe.

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
Able to control an expansion valve directly with simultaneously analog 4-20mA output to a PLC
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


Rod style sensor mounted in an elbow:

Rod style sensor mounted in an elbow


Rod style installation:

Rodstyle installation


Connection Diagram

HBX connection diagram


Thread: 1" BSP(G)HBX Rod 1" Ø28mm

Thread: 3/4" BSP(G) & NPT
Length: 190 mmHBX Rod 3/4" Ø22mm L190mm

Thread: 3/4" BSP(G) & NPT
Length: 300 mmHBX Rod 3/4" Ø22mm L300mm

Power supply
Voltage24 V AC/DC
Current consumptionMax 600 mA
Electronic connectionM12, 5 pins
Analog output4-20 mA
LED indicationGreen, yellow, and red
Environmental conditions
Ambient temperature-30...+50°C
Refrigerant temperature-60...+80°C
Max. pressure100 bar
Degree of protectionIP65
Vibrations IEC 60068-2-6 (4g)
Mechanical specifications
Material - mechanical partsAISI 304 / PTFE
Material - electronic partsNylon 6 (PA)
DimensionsSee drawing
EMC testEN 61000-2
Cable specification (power supply)
Cable size5 m - 5 x 0.34 mm2
Cable glandsPG7 / M8
Cable resistance500 Ohm/Km
Configuration HB Tool
Tool to be used HBX software
Valve control (Modulating valve)
Signal to valve4-20 mA
Valve regulationPI-regulation
Valve control (PWM)
Signal to valve24V AC/DC
PWM period0-120 s (default 6 s.)
Valve control (Stepper motor)
Stepper motor steps25-5000 steps
Stepper motor speed2-40 m/s
Stepper motor phase current0-750 mA
Stepper motor holding current0-250 mA
Cable specification (valve control)
Length3 m (118”)
Cable size3 x 0.75 mm2
Cable glandsPG7 / M8

Ordering code

Insert lengthConnectionDirect valve control - CableOrdering code
HBX-DXbasic version4…20 mA outputfor NH3 DX-systems
190 mm3/4" NPTNAHBX-DX-R-2-2
190 mm3/4" BSPPNAHBX-DX-R-2-6
300 mm3/4" NPTNAHBX-DX-R-3-2
300 mm3/4" BSPPNAHBX-DX-R-3-6
300 mm1" BSPPNAHBX-DX-R-3-8
300 mm1" NPTNAHBX-DX-R-3-8
Electronic Part for HBX-DX sensor Must be calibrated on-siteHBX-DX-EL
HBX-CRbasic version4…20 mA outputfor use in overfeed systems
190 mm3/4" NPTNAHBX-CR-R-2-2
190 mm3/4" BSPPNAHBX-CR-R-2-6
300 mm3/4" NPTNAHBX-CR-R-3-2
300 mm3/4" BSPPNAHBX-CR-R-3-6
300 mm1" BSPPNAHBX-CR-R-3-8
300 mm1" NPTNAHBX-CR-R-3-8
Electronic Part for HBX-CR sensor Must be calibrated on-siteHBX-CR-EL
HBX-DX/CControl version4…20 mA outputfor NH3 DX-systems
190 mm3/4" NPTModulating ValveHBX-DX/C-R-2-2
190 mm3/4" BSPPModulating ValveHBX-DX/C-R-2-6
300 mm3/4" NPTModulating ValveHBX-DX/C-R-3-2
300 mm3/4" BSPPModulating ValveHBX-DX/C-R-3-6
300 mm1" BSPPModulating ValveHBX-DX/C-R-3-8
300 mm1" NPTModulating ValveHBX-DX/C-R-3-8
Electronic Part for HBX-DX/C sensor Must be calibrated on-siteHBX-DX/C-EL
HBX-CR/CControl version4…20 mA outputfor use in overfeed systems
190 mm3/4" NPTModulating ValveHBX-CR/C-R-2-2
190 mm3/4" BSPPModulating ValveHBX-CR/C-R-2-6
300 mm3/4" NPTModulating ValveHBX-CR/C-R-3-2
300 mm3/4" BSPPModulating ValveHBX-CR/C-R-3-6
300 mm1" BSPPModulating ValveHBX-CR/C-R-3-8
300 mm1" NPTModulating ValveHBX-CR/C-R-3-8
Electronic Part for HBX-CR/C sensor Must be calibrated on-siteHBX-CR/C-EL
HBX-DX/PWMControl version4…20 mA outputfor NH3 DX-systems
190 mm3/4" NPTPulse Width Modulation ValveHBX-DX/PWM-R-2-2
190 mm3/4" BSPPPulse Width Modulation ValveHBX-DX/PWM-R-2-6
300 mm3/4" NPTPulse Width Modulation ValveHBX-DX/PWM-R-3-2
300 mm3/4" BSPPPulse Width Modulation ValveHBX-DX/PWM-R-3-6
300 mm1" BSPPPulse Width Modulation ValveHBX-DX/PWM-R-3-8
300 mm1" NPTPulse Width Modulation ValveHBX-DX/PWM-R-3-8
Electronic Part for HBX-DX/PWM sensor Must be calibrated on-siteHBX-DX/PWM-EL
HBX-CR/PWMControl version4…20 mA outputfor use in overfeed systems
190 mm3/4" NPTPulse Width Modulation ValveHBX-CR/PWM-R-2-2
190 mm3/4" BSPPPulse Width Modulation ValveHBX-CR/PWM-R-2-6
300 mm3/4" NPTPulse Width Modulation ValveHBX-CR/PWM-R-3-2
300 mm3/4" BSPPPulse Width Modulation ValveHBX-CR/PWM-R-3-6
300 mm1" BSPPPulse Width Modulation ValveHBX-CR/PWM-R-3-8
300 mm1" NPTPulse Width Modulation ValveHBX-CR/PWM-R-3-8
Electronic Part for HBX-CR/PWM sensor Must be calibrated on-siteHBX-CR/PWM-EL
HBX-DX/SControl version4…20 mA outputfor NH3 DX-systems
190 mm3/4" NPTStepper Motor ValveHBX-DX/S-R-2-2
190 mm3/4" BSPPStepper Motor ValveHBX-DX/S-R-2-6
300 mm3/4" NPTStepper Motor ValveHBX-DX/S-R-3-2
300 mm3/4" BSPPStepper Motor ValveHBX-DX/S-R-3-6
300 mm1" BSPPStepper Motor ValveHBX-DX/S-R-3-8
300 mm1" NPTStepper Motor ValveHBX-DX/S-R-3-8
Electronic Part for HBX-DX/S sensor Must be calibrated on-siteHBX-DX/S-EL
HBX-CR/SControl version4…20 mA outputfor use in overfeed systems
190 mm3/4" NPTStepper Motor ValveHBX-CR/S-R-2-2
190 mm3/4" BSPPStepper Motor ValveHBX-CR/S-R-2-6
300 mm3/4" NPTStepper Motor ValveHBX-CR/S-R-3-2
300 mm3/4" BSPPStepper Motor ValveHBX-CR/S-R-3-6
300 mm1" BSPPStepper Motor ValveHBX-CR/S-R-3-8
300 mm1" NPTStepper Motor ValveHBX-CR/S-R-3-8
Electronic Part for HBX-CR/S sensor Must be calibrated on-siteHBX-CR/S-EL
AccessoriesUSB programming cable HBxC-USB