Methods in measuring moisture content for drying

Weight reduction (primary method)

Electrical characteristics (secondary method)

Oven method

IR balance

Capacitive MC meter

Resistance MC meter

Principle

Evaporation of water at high temperature. Calculation of moisture from initial weight and dry matter weight

Detection of weight loss by heating and drying

Grain is filled in between two plates of a capacitor. Water contents affects dialectical properties

Electrical resistance of crushed grains

Water affects resistance.

Advantage

Most exact method

More accurate than quick moisture meters (0.1%)

Covers full range (0-100%MC)

Automatic operation

More accurate than resistance type MC meters (0.2-0.5%)

Portable

Fast readings.

Very portable

Affordable

Rugged

Small sample size

Constraint

Expensive oven with temperature control needed

Long process time

Relatively long process time (10-30 minutes)

Sensitive mechanics

More expensive than resistance type MC meters

Larger sample sizes

Lowest accuracy (typically 0.5%)

Limited MC range

Application

Reference in research

Laboratory

Research

Laboratory and field

Field and laboratory, grain industry