Chemical industry, process automation

Automatic height adjustment for material analysis

Laser-induced breakdown spectroscopy (LIBS) performs precise analysis of the atomic composition of different materials. The measurement objects involved are mostly mineral or metallic parts whose surfaces have different gloss levels and which are sometimes extremely tilted.

SECOPTA analytics GmbH uses the ILD1320-100 sensors from Micro-Epsilon in this application to automatically readjust the height of the LIBS sensor head. Particularly with metal samples whose surfaces have different textures such as oxidized spots, the ILD1320 with the ATC feature is a reliable sensor.

Sensor technology applied

On-line inspection of sealing compound in covering lid

After injection of the sealing compound in the covering lid, curing takes place in the tunnel furnace. Here, fault points and faulty thicknesses of compound must be acquired and faulty lids must be sorted out in the production process. A laser-based optical displacement measurement system samples the compound surface of the rotating lid for a quality inspection. The monitoring of the thickness contour within the permissible tolerance limits and the sorting of the faulty lids occurs with the aid of the PLC that is employed.

Sensor technology applied

Extruder bore diameter

The idiamCONTROL system has been developed for checking the wear of extruder bores. The measuring cylinder is inserted in the case bore and pushed as far as the upper end. During retraction of the cylinder, several capacitive sensors measure the case diameter on several tracks. Specially for double worm extruders, the measuring cylinder has two metal pins which run along the saddle of both bores and in this way prevent rotation of the cylinder.

Sensor technology applied

Absolute and continuous filling-level measurement

Continuous acquisition of the level must be ensured for high precision monitoring of filling levels. These requirements can be obtained with a MICROEPSILON vipSENSOR element whereby the actual sensor is integrated into a specified housing. The specified length of immersed tube can be optimally used as the measurement range due to the compact design and the very short installed length of the sensor element. This ensures a highly accurate, continuous filling level measurement from completely filled to completely empty.

Sensor technology applied

Control and monitoring of the production sequence in a refinery

In the refinery crude oil is cracked by distillation to give petroleum, kerosene and diesel oil. In the fractional distillation column the crude oil is heated with superheated steam. The vapors and liquids released collect in the various stages of this column. To control and block the flow of gases and liquids the spindle drives of the numerous flow control valves are fitted with long-stroke sensors. An aluminum tube is used here as the measurement object which is moved concentrically over the sensor coil rod without making physical contact. A displacement signal in the range 4 to 20 mA is provided for the aluminum tube position or for the valve position.

Sensor technology applied

Layer thickness measurement (non contacting)

Layer thickness measurement belongs to the group of one-sided, non-contact thickness measurement. Basically, only the layer thickness of electrical insulators can be measured for opaque objects. An eddy current sensor penetrates the insulating layer without damage and measures the distance to a layer underneath it. At the same time, a second sensor, a laser triangulator measures the insulating layer. The layer thickness is obtained by offsetting both signals. This method of measuring with two sensors using different principles is called the dual sensor technique by Micro-Epsilon. A second possibility is the layer thickness measurement of transparent materials using confocal measurement technology. The emitted white light penetrates the measuring object and provides a peak in the signal graph at every material transition. For example, the film thickness between two glass panes can be easily measured in this way.

Sensor technology applied

Filling level

A filling level measurement situation can arise with a liquid substance as well as with dry, bulky goods. The precise measurement of liquid levels is difficult to achieve, nevertheless, the confocal measuring technique is a suitable solution for this problem. Light is also reflected on the surface of liquids and thus provides a reliable result. Filling levels of dry bulk materials are easier to measure due to the surfaces. The ILR Time-of-Flight sensors are suitable for deep containers. Laser sensors from the optoNCDT group are available for shorter sections.

Sensor technology applied

Active damping of liquid-cooled centrifuges

At certain configurations of speed, filling level and design parameters, liquid-filled industrial centrifuges tend to produce unstable running characteristics which can lead to failure of the centrifuge. The instability, which arises due to interaction between the fluid and the centrifuge, cannot be rectified by passive means (dampers), so therefore the instability is corrected actively with the aid of a magnetic bearing and suitable closed-loop controllers. The deflection of the rotor, which is acquired with two eddy-current sensors orientated at 90° to one another, is used as input information for the controller.

Sensor technology applied