Differing production conditions make the use of special measuring systems for controlling flow velocities and volume flows a necessity. The measuring technique is pushed to its limit when measuring in contaminated airflow. Höntzsch Waiblingen manufactures exceptionally corrosion resistant vortex flow sensors especially for this purpose. Their exact measuring data is the prerequisite for an optimum temperature control in modern soldering works. The vortex flow sensors are also used by Miele & Cie GmbH & Co, Gütersloh, where they contribute to the smooth running of manufacture.

The temperature of the solder bath is a sensitive criterion in the industrial layout of solder baths for electronic boards. The electronic elements which run through the solder bath on boards can be destroyed by excessive heat. This applies especially to boards which are equipped with modern SMD semiconductors.

Special deaerators are used to bring the temperature into exacting ranges of tolerance. These enable the necessary solder temperature to be maintained and also ensure that the sensitive components are protected. The exact measurement and control of the air volume or air velocity respectively is crucial for the optimum operatability of the deaerators.

As resinous outgoing-air arises from solder baths, not only the vane wheel and thermal flow sensors, but also the sensors that work with the differential pressure measuring system, are put out of action and another measuring method must be chosen. With the vortex flow sensors air flow with high exposure time and precision can be measured even in resinous mediums. The vortex principle of measurement is derived from the Karman phenomenon of vortex shedding. It is based on vortices being shed when a flowing medium reaches an obstruction, whereby the vortex shedding frequency is a dimension for the flow velocity.

For this application the evaluation unit with keypad and display is additionally combined with a printer. The keypad enables the requisite input of the relevant design information and sensor data as well as the configuration of the analog output and the printer. Moreover the display permits the visual control of the measuring data.

The analog ouput can be used for the continuous recording of the measured value or otherwise as instantaneous value input for regulators. The ventilator rotational speed and consequently the air velocity or the volume flow can be set via the regulator.

The Höntzsch vortex flow sensors play an important role in the temperature control of modern soldering works. Their operatability is not impaired by the resinous outgoing air to be measured.