For further information on our newest thickness measurement system please check our flyer alpha.ti 2.0.
Contactless online thickness measurement - alpha.ti
The manufacturing of strip-like products requires the measuring of the thickness to keep specified tolerances while guiding the manufacturing process securely. nokra offers measuring systems to be integrated in a production line for a contactless online thickness measurement. These systems measure the thickness continuously without any delay providing the decisive information to improve the manufacturing process and to achieve an efficient quality assurance.
The laser measurement is based on the principle of laser triangulation. The laser measuring systems of nokra are specified and inspected on the basis of established national and international standards as well as on the guideline „Measurement System Analysis“ of the international car manufacturer and supplier industry.
The key component of a thickness measuring system are laser triangulation sensors for the measurement of distances. The thickness is determined using the synchronously measured distance values from the top and bottom side of the strip-like product.
Material independent measurement
Laser thickness measurement is capable to measure various kinds of materials, such as metal, foam, plastics, mineral rock wool, nonwoven fabrics, elastomers, wood, paper. Thereby, the properties of these materials vary in a wide range: from metallic glossy surfaces to surfaces with scale layers, from white to black, from smooth to rough, from cold to red-hot, from opaque to translucent. The laser measures the thickness of the material independent from the specific material density. This is valid for red-hot steel as well as for porous foam. A knowledge about the composition of the material is not necessary.
The laser sensors of nokra applied for thickness measurements offer a significantly improved precision in comparison to conventional sensors. nokra laser sensors are based on a new method gaining an enlarged information from the measuring radiation.
|Feature||Laser measurement||Tactile probe||Radiometric measurement|
|Fast reaction on thickness changes||+||-||-|
|Small measuring spot||+||+||-|
|Low maintenance effort||+||-||-|
|Harsh operating conditions||+||+||+|
|Measuring object||Laser measurement||Tactile probe||Radiometric measurement|
|Independent to density variations||+||+||-|
|Independent to changes of the material composition||+||+||-|
|Measuring principle||laser triangulation||laser triangulation|
|Measuring range of upper sensor/distance to passline||25 mm/115 mm||80 mm/265 mm|
|Measuring range of lower sensor/distance to passline||8 mm/35 mm||8mm/35 mm|
|Thickness of measured material||max. 6 mm||max. 12 mm|
|Diameter of measuring spot||0,05 mm||0,1 mm|
|Velocity of material to be inspected||5-2000 m/min||5-2000 m/min|
|Surface/Material properties||no restrictions, examples: metallic glossy, scale layers, dark, porous, coloured||no restrictions, examples: metallic glossy, scale layers, dark, porous, coloured|
|Sample frequency||up to 50 Hz||up to 50 Hz|
|Integration time||1-1000 ms||1-1000 ms|
|Accuracy of thickness measurement||+/- 0,001 mm||+/- 0,003 mm|
|Adjustment||automatic adjustment procedure||automatic adjustment procedure|
|Window protection system||An aerodynamically optimized air wipe unit keeps the sensor's optical window free of dust and rolling oil||An aerodynamically optimized air wipe unit keeps the sensor's optical window free of dust and rolling oil|
|Laser class||1 to 3 R||1 to 3 R|
|Ambient temperature for measuring operation||-5 to +60° C (if ambient temperature is > +45° C, external cooling is needed)||-5 to +60° C (if ambient temperature is > +45° C, external cooling is needed)|
|Humidity||not condensing||not condensing|
|Output signals||analog, profibus, profinet, TCP protocol, output frequenzy adjustable||analog, profibus, profinet, TCP protocol, output frequenzy adjustable|
|Input signals||incremental encoder, trigger signals, profibus, profinet, ethernet (TCP/IP protocol)||incremental encoder, trigger signals, profibus, profinet, ethernet (TCP/IP protocol)|
|Protection class of C-frame||IP 65||IP 65|
|Life time of laser modules||MTBF=80.000 hours||MTBF=80.000 hours|
|B=400-1250 mm||B=400-1250 mm|
|C=150 mm||C=350 mm|
|D=mind. 190 mm||D=mind. 190 mm|