AB Lorentzen & Wettre Paper TSO Tester

L&W TSO Tester

Rapid analysis of twist and runnability

L&W TSO Tester is an ultrasonic instrument for measuring Tensile Stiffness Index (TSI) and the Tensile Stiffness Orientation (TSO) properties on sheets and cross machine paper samples. In the QC shift laboratory the results are used to predict the performance of paper, in a sheeting process, multicolour printing process, laser copying machines, and corrugated board manufacture. It is also an ideal tool for process optimization, as it allows you to take early action in the headbox, press and dryer, saving raw material, as well as time. Correlation to strength properties such as RCT and SCT can also be performed.


L&W TSO Tester measures TSI and TSO properties on sheets and cross-machine paper samples. The acquired measurement data are used for optimizing the performance of important stages of the machine process, such as headbox, press section and dryer.

A typical cross-directional measurement is usually performed within five minutes, and provides complete information on the full web width, including edges. Thus, the TSI and TSO profiles can be determined at every reel change. Early action can be taken against possible deviations in the following reel, keeping the TSI and TSO values as well as any calculated strength properties within pre-determined limits.

L&W TSO Tester is also an ideal instrument for troubleshooting of head-box problems such as pressure pulsations or a deviating pressure profile.

With the help of correlation data the TSI value can also be used for calculating strength properties such as SCT and RCT.

In the laboratory, L&W TSO Tester is a flexible tool for reliable predictions of the runnability of a paper in applications like copying, printing or board conversion.

Easy to use

L&W TSO Tester is easy to use. The test strip is quickly cut from the reel, using the profile sample cutter from Lorentzen & Wettre.

The strip is then attached to the instrument’s feeder, and the measurement sequence is automatically performed at the push of a button. The measurement speed is about six seconds per measuring point. Thus, the total time required for a complete profiling sequence, will depend on the length of the sample and the distance between measuring points.

This distance can be 10–2 000 mm. Large intervals are used in measuring test strips cut in the machine direction. Test strips can be several hundred metres long. All measurements are stored in a database, from which they can be displayed on a computer screen or printed as profile graphs for TSIMD, TSICD, TSIMD/CD, TSIAREA, TSOANGLE or other machine-specific characteristics. Once all the measurements have been made they can be either archived in a special area of the database or transferred as XLS or HTML files to other systems via e-mail or FTP. The measuring program can display superimposed or three-dimensional graphs that make the measurements easier to understand. L&W TSO Tester consists of a table-top ultrasonic measuring unit with feeder attachment and a PC with printer and software.

The complete measuring station can be placed either in the machine control room or in the laboratory. All results can be stored for further analysis or for transfer to other computers. TSO and TSI properties can also be measured in the automatic L&W Autoline 300 (see page 81).

  • Measures with the ultrasonic technique
  • Automatic measurement of cross directional and machine directional TSI and TSO profiles
  • Rapid measurement – six seconds per test point
  • Additional values can easily be entered by operator, to determine correlations between TSI and other properties
  • Shows result as a polar diagram or profile, including statistics and grade limits
  • Results are stored as data files for further computer processing
L&W TSO Tester – Code 150
PC, printer, software and test film


Ultrasound propagation speed in the plane of the sheet
Measuring time
6 s per test point

Distance between measuring points

10–2000 mm


30–500 g/m²

Instrument and program

 Measurement values
- calculated properties
Graphical reports
- Polar diagram and profile graphs on the screen and printer
- mean value
- max. and min. value
- standard deviation/coefficient of variation
- number of values

Targets, grade targets, alarm limits

Installation requirements
900 W
Instrument air
0,6 MPa
Air consumption
0.3 l/min NTP for 10 measurements per min

L&W Profile Sample Cutter (code 148) and L&W Sample Trimmer (code 149)




L&W TSO Tester

0.6 × 0.6 × 0.4 m
24 × 24 × 16 ín

0.31 m³
11 ft³

0.5 × 0.7 × 0.4 m
20 × 27 × 16 in
0.6 m³
21 ft³
0.4 × 0.4 × 0.3 m
16 × 16 × 12 in

Net weight

Gross weight
L&W TSO Tester
38 kg
84 lb
58 kg
128 lb
PC and printer
41 kg
90 lb
62 kg
137 lb


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