Digicolor DFM-3 Residual Moisture Analyzer

The DFM-3 is a measuring instrument used to determine the amount of residual moisture in solids and especially in plastic granulate. It is robust and compact in construction and portable: instead of sending the sample to a laboratory, you can take the instrument to the production floor.

How does it measure?

The instrument determines the amount of water by a chemical route. The sample is heated in a reactor, and the moist hot gas given off passes to the upper part of the reactor. There a reagent converts the water to hydrogen and a sensor measures the hydrogen concentration. Unlike weighing-based moisture balances, this patented measuring method measures only water; volatile additives do not inflate the result.

The measurement is run by a PC program. Because the program guides the user step by step, the chance of an operating error is low and every measurement is recorded.

Where is it used?

• Incoming quality control: does the moisture of the incoming batch meet the specification
• Monitoring and optimizing drying: is the dryer really reaching the target
• Sampling from the feed zone: the moisture of the material entering the machine
• Laboratory measurement

Residual moisture tolerances are set by the material manufacturer; the measurement standard is DIN EN ISO 15512. We explain the difference between dew point and residual moisture in our moisture and dew point measurement article: dew point measures the air, residual moisture measures the granule, and one does not replace the other.