Dry matter

Determination of the dry matter of a starting material (here: chopped maize ) for energy generation in a biogas plant

The dry mass or dry matter (DM) is that part of a substance that is left of the water contained after deducting the crowd: ${\displaystyle m_{T}}$

${\displaystyle {\begin{alignedat}{2}&m_{T}&&=m_{\mathrm {ges} }-m_{W}\\\Leftrightarrow \,&m_{T}+m_{W}&&=m_{\mathrm {ges} }\end{alignedat}}}$

Are in it

• ${\displaystyle m_{T}}$ the mass of dry matter
• ${\displaystyle m_{\mathrm {ges} }}$ the total mass of the sample
• ${\displaystyle m_{W}}$ the mass of the water.

In relation to the total mass results:

${\displaystyle \Leftrightarrow TS+W=1=100\,\%}$

d. H. Dry matter content and water content complement each other 100 percent, with

• ${\displaystyle TS={\frac {m_{T}}{m_{\mathrm {ges} }}}={\frac {m_{T}}{m_{\mathrm {ges} }}}\cdot 100\,\%}$( Mass fraction of dry matter = dry matter)
• ${\displaystyle W={\frac {m_{W}}{m_{\mathrm {ges} }}}={\frac {m_{W}}{m_{\mathrm {ges} }}}\cdot 100\,\%}$(Mass fraction of the water = water content ).

The dry matter content is used in different areas:

• In the Waste Management , especially for organic waste and residual waste , the TS is often next to the fresh mass than of interpretation size as well as criteria for deposition on landfills used
• In the wood industry for wood moisture (also in a different definition)
• In the case of cheese , the fat content for the consumer is often given as a percentage of fat in the dry matter ( fat in dry matter ) - in Germany, Austria and Switzerland, this information is required by ordinance . Sometimes in addition to this, and also in other countries (for example in France), the information related to the total weight can also be found.
• In food and feed analysis , the dry matter is usually determined gravimetrically by drying a sample in a drying cabinet at just over 100 ° C. The importance of dry matter results from the fact that all other content information is usually based on it.
• For cocoa and other oil fruits, the information for the press cake after cold or warm oil removal applies.
• In the sugar industry , the dry matter content is an important control variable for crystallization and is now often measured in real time using microwave measuring devices.

See also

• Sludge index # dry matter content

proof

1. ↑ Michael S. Hand: Clinical dietetics for small animals . Schlütersche, 2002, ISBN 3-87706-893-6 , p. 12 ( limited preview in Google Book search).
2. ^ Michael Wächter: Chemielabor - Introduction to Laboratory Practice , Wiley-VCH Verlag, Weinheim, 1st edition, 2011, p. 63, ISBN 978-3-527-32996-0 .
3. ↑ Microwave measuring device ( Memento of the original from October 18, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.