Changing and measuring consistency

A measuring device for measuring at least one property of a sample comprising a fibre suspension having at least two consistencies, the measuring device comprising:

• at least one measuring unit;
• and
• at least one mixer structure configured to receive the sample comprising the fibre suspension from at least one process part, the sample having a predetermined consistency, the at least one mixer structure comprising:
• a sample line;
• at least one mixer as part of the sample line;
• a feeding valve configured to feed a feed liquid into the sample line to move the sample forward in the sample line to the measuring unit;
• and
• a mixing valve structure configured to feed a dilution liquid into the sample line;
• and
• wherein:
• the at least one mixer is configured to mix the sample and the dilution liquid together to change the consistency of the sample;
• the measuring unit is configured to:
• measure at least one property of a first part of the mixed sample after the feed liquid has moved the first part of the mixed sample through the at least one mixer and into the measuring unit;
• and
• then measure at least one property of a second part of the mixed sample after the feed liquid has moved the second part of the mixed sample through the at least one mixer and into the measuring unit;
• and
• the at least one property comprises a consistency of the sample comprising the fibre suspension.