DLT-5500 Dissolved Lignin Transmitter

Accurate inline measurement of dissolved lignin in pulp suspension


  1. Key parameter in fiberline operations control
  2. Improve brown stock washing
  3. Enhanced oxygen delignification and D0 operations
  4. Reduce chemical costs
  5. Lower energy costs in evaporation plant
Creping Excellence - page

DLT-5500: Dissolved lignin

Direct determination of dissolved lignin in pulp slurry

The Dissolved Lignin Transmitter DLT-5500 is a sensor which measures the dissolved lignin concentration in pulp suspensions or filtrates using a unique principle based on optical measurement. The sensor is pre-calibrated and requires only one measurement onsite for the final calibration. The results can be correlated to either a filtrate kappa or chemical oxygen demand (COD).

This sensor is ideal for determining black liquor carry-over into bleach plants and black liquor solids in brown stock washing and oxygen delignification.


Traditional application rate of ClO2 on the D0 stage is determined by measuring the lignin content of washed fibers via a kappa analyzer or laboratory test. The ClO2 is then applied based on the washed fiber kappa. While the lignin in the fiber consumes most of the ClO2, the traditional washed fiber kappa does not account for the dissolved lignin that enters the D0 stage from the brown stock washing area.

The lignin in the black liquor will rapidly consume the ClO2 leaving insufficient ClO2 to delignify the pulp. There are several other methods currently used to warn the operator of black liquor in the pulp.

DLT5500 model image

Moving manufacturing forward

BTG integrates solutions for sustainable gains in business performance across your operations

Best in-class solutions

Leading-edge product application solutions deliver best-in-class solution for manufacturing

Proven cross
Proven cross-mill benefits

An integrated whole-of-mill approach that unlock new levels of process optimization

Trusted at every level

Measurable performance gains that support operational, maintenance and project professionals

Value added services

  • BTG’s Mütek lab devices create cost savings through optimized chemical dosage and reliable, stable operation
  • A new, fast and accurate method to optimize polymer dosage for dewatering processes in ‘ effluent treatment
  • BTG’s Mütek PCD opens up new options for measurement of grain products, raw materials, additives and finished products

Download Resources

Get Access to our marketing materials, installation guides etc,.

Go to top

This content is automatically translated