Although the ceramic ultrasonic and thermal sensors of Arenal PCS can be applied in any liquid in the world, it is mainly designed for abrasive slurries and pastes, which can be found in Mineral and Metal processing plants, dredging and tunneling. Arenal is actively involved in industrial slurries, like in CMP, pigment and catalysts slurries and battery pastes and potato starch slurries.

The optimal slurry for measuring density, flow and massflow is a homogene turbulent slurry in a pipe or vessel, with a large concentration of particles below 1 mm.

Hydrochloric acid is a solution of hydrogen chloride in water:


HCl + H2O is in equilibrium with H3O+ + Cl


Some points of use in the industry

  • Vinyl chloride for PVC
  • MDI/TDI for polyurethane
  • Production of cleaning agent
  • Many other applications




The technology of Ultrasonic Density is explained here.


Our probes

Arenal offers a variety of probes to measure HCl concentrations online:


  1. If a general indication of the concentration is required, our torroidal (electrodeless) conductivity sensor is suitable for the full range 0-36 wt%, except for the range 16-22 wt% or Baumé (Bé). In this small range, the conductivity curve bends and the accuracy of the sensor is too low to determine small variations. We can offer PP, PVC, PVDF torroidal probes. Interested? Fill in the questionnaire and request the QP025-TCP-INL probe.
  2. If highest accuracy is required, the ultrasonic spectroscopy sensor is the best choice. The speed of sound graph gives a similar signal as the the conductivity, and is more accurate, which makes the sensor ideal for use in a broad range and for determining its concentrations on 4 digits over the full range. The materials used are PP or PVDF and zirconiumoxide (ZrO2): only the extractive analysis embodiment is possible at the moment.



When choosing ultrasonic spectroscopy sensors, we herewith help you selecting the correct products. Arenal offers solutions for applications with a variety of embodiments. Actually in most cases only the probe size, body shape, body material and sensor material changes, while the transmitter and Analysers keeps the same.


Embodiment type 
Extractive analysis in teflon QB Blocks
Sanitary probes
Submersible probes
Wafer cells between flanges of pipes
Inline analysis in pipe lines
(Trans)portable probes
Laboratory probes