Inline monitoring of pickling processes (Dynamic Acid Control)

Improved pickling: With sound velocity for the optimal concentration.

When it comes to industrial metal pickling processes, the desired consistently high product quality and the system productivity significantly depend on one important criterion: a consistently optimised setting of the acid concentration in the pickling bath. Manual concentration monitoring requires a lot of material and personnel, yet delivers deficient and inaccurate results, so the required adjustment are also unable to lead to a consistently optimal concentration.

The clever solution is called DynAcid (Dynamic Acid Control), a continuous inline concentration measurement. The solution involves installing a bypass with the DynAcid system on the pickling bath. The sensors then continuously measure four areas: temperature, sound velocity, conductivity and refractive index. Based on these four values, DynAcid determines the acid concentration and presents it in real time for automatic process control. The benefits are obvious: a steady, improved product quality and reduced acid use, time savings and savings with regard to cost-intensive chemical analysis.


Technical data:


Pickling bath temperature: up to 98 °C
Ambient temperature: up to 40 °C
Concentration of free acid: up to 240 g/l
Concentration of salts (as Fe2): up to 200 g/l

Test method and accuracies:


Temperature: +/- 0.1 K
Ultrasonic velocity: +/- 0.1 m/sec
Electric conductivity: +/- 0.001 S/cm
Concentration of free acid: +/- 10 g/l
Concentration of salts (as Fe2): +/- 5 g/l

BFI solution Brochure Request information material

The DynAcid system is based on a measurement principle developed by the institute for scientific research, VDEh-Betriebsforschungsinstitut (BFI, Düsseldorf). Production and distribution under DEh-Betriebsforschungsinstitut licence