WCA July 2008

and

(of wires & cables)

Measurement at the top of the draw tower LIS-G instruments (Laser Interferometric Sensors for Glass) from Cersa-MCI are widely used in optical fibre manufacturing for bare diameter measurement and fine airline and glass defect detection. The metrology performance of the LIS-G makes spinning measurement at the top of the draw tower possible using the Non Circularity (NC) of the fibre, even down to 0.05µm of NC.

Graph 1 ❍ ❍ : A modelling of a critical “triangle” shape, with a large amplitude fluctuation and frequency change, with over diameter modulation to test signal computing

Graph 2 ❍ ❍ : A modelling of a constant signal amplitude, constant period, constant frequency, showing a slight shape (width) difference between peaks, one and two

Cersa-MCI’s LIS-G5 offers absolute in-line diameter measurement within ±0.15µm, highly stable, with no need for periodic calibration; repeatability and

stability within ±0.004µm at 50kHz band pass, and independent fibre vibration measurement. LIS-G instruments give an exact view in real time of the dimensional characteristics of the fibre, allowing users to perfect the drawing process, to maintain the fibre at high diameter stability, and to certify the whole production characteristics.

Graph 5 ❍ ❍ : Shows the spinning frequency profile (Spinning evolution) as well as its FFT. The FFT peak shows a 2 Hz frequency, which means one hertz of profile period. The peaks are alternatively directions

Graph 3 ❍ ❍ : The results on a typical real signal recorded by the LIS-G on a draw tower and its display on FiberWin PC software. NC = 0.07µm , 2 peaks per turn (Signature). This is close to the measurement limits

Graph 4 ❍ ❍ : The results on a typical real signal recorded by the LIS-G on a draw tower and its display on FiberWin PC software. NC = 0.24µm , 2 peaks (almost 3) per turn.

At high drawing speed it is challenging to produce fibres of less than 0.05µm of NC. However, with a typical NC of 0.1µm at 125µm, the instrument shows clearly the spinning influence on the diameter fluctuation. As the circumference of the fibre section is not perfectly round, the LIS-G diameter fluctuation shows a ‘one turn signature’. The diameter is recorded at an appropriate time resolution over several spinning periods and then, using signal computing, the ‘signature’ can be recognised. To do that, Cersa-MCI has developed its own correlation function (EATP) to show spinning frequency, peak-to-peak non-circularity amplitude and the spinning frequency profile, even though the spinning frequency changes continuously. The ‘one turn signature’ might be 2 peaks (oval), 3 peaks (triangle) or even 4 peaks (square) due to the NC shape. To validate the signal computing, Cersa-MCI simulated specific limit signals in shapes and amplitudes. Then the in line experimentations gave excellent results. Today more than 20 draw towers benefit from this extended feature.

Cersa-MCI – France Fax : +33 4 42 02 79 79 Email : sale@cersa-mci.com Website : www.cersa-mci.com

For ten years, iiM AG has been developing and producing devices and software for measurement of geometric cable-attributes and corresponding CAQ-systems. The resulting technology, VisioCablePro-series devices, FMC-2 software and ProCable CAQ-system, offer quick and accurate measurement of conductor isolations and sheaths. The newest optical measuring instruments VCP-03 and VCPS-01 are designed for evaluation by optimal coloured video pictures of cable profiles. These devices provide a robust workstation for manual checking in the laboratory or production facility. The very high resolution enables precise measurement of test cables up to 150mm diameter. Solutions for cable producers

FMC-2 software automatically measures and evaluates data and the third system component, the CAQ-system ProCable archives measurement and logistical data and facilitates test planning, data entry and analysis. Using fast, precise measurements and detailed information about material consumption, the VCP-series can make extruder setup and final cable check more efficient and quicker, while maintaining tolerance and quality guidelines.

iiM AG – Germany Fax : +49 369 3885 8511 Email : krapick@iimAG . de Website : www . iimag . de

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Wire & Cable ASIA – July/August 2008