AB Lorentzen & Wettre Felt Permeability Meter

AB Lorentzen & Wettre Felt Permeability Meter

There is a lot we can do to optimize the production

L&W Felt Permeability Meter is a new instrument from Lorentzen & Wettre which, provides you with the best possible knowledge about the condition of the press felts. This enable you to optimize dewatering and reduce costs significantly.

L&W Felt Permeability Meter quickly and accurately measures the water permeability of press felts during operation. By measuring the water permeability of the felts, clogging and wear are easily discovered and the potential to optimize the pressing with regards to paper quality and dewatering is made possible. The instrument also measures felt length as well as giving measurement positions in relation to the machine width. The instrument can be used to optimize the conditioning system as well as for quick troubleshooting. L&W Permeability Meter is both smaller and lighter than its predecessor and includes position detection of both MD and CD, 2- and 3-dimensional images of the felt permeability as well as a frequency analysis conducted on all measurement results. Regular measurements with L&W Felt Permeability Meter lead to optimized use of cleaning chemicals, increased felt life, efficient dewatering, high and uniform product quality and reduced machine downtim.



  • A more consistent operation
  • Reduced energy consumption
  • A more balanced chemical usage
  • Reduced emissions
  • Reduced wear and maintenance requirements
  • Increased production


L&W Felt Permeability Meter – Code 891
L&W Felt Permeability Meter, L&W Position Reference, battery charger with power cable, 12V cable for car, USB cable, calibration check nozzle, software CD for PC, user manual, carrying case


50–3000 ml/min
Resolution [H2O]
1 ml/min


Colour 320 × 240 Pixels
Measurement Rate
100 values/s
Measuring area
2.5 or 4 mm diam. (0.1 or 0.16 in)
Measuring series
max 50
Measuring time/series
max 30 minutes
Battery type
Li-Ion ( capacity min 2200 mAh)
Battery time
approx. 2.5 h
Charging time
max 6 h
128 MB
Input voltage
11–24 V DC


Measurement values
- Flow  ml/min
- Pressure Bar, kPa, Psi


USB 2.0

Installation requirements

Operating temperature
15°C–60°C (60°F–140°F)
Operating humidity
max 100% RH


0.28 × 0.26 × 0.12 m
11.6 × 10.4 × 4.9 in
0.025 m³
0.9 ft³

L&W Position Reference
0.21 × 0.12 × 0.09 m
8 × 5 × 4 in

Aluminum carrying case
0.42 × 0.18 × 0.32 m
16 × 7 × 13 in

Net weight
3.3 kg
7.3 lb
Weight incl.
9.9 kg
21.8 lb


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