This Technical Information Paper describes a method for measuring moisture in rolls of containerboard using a hand held moisture meter, one that is capable of measuring changes in the dielectric constant of the containerboard due to the presence of moisture.
As the dielectric constant is also affected to a large degree by the density of the roll of containerboards, it is necessary to compensate for density when using a hand held moisture meter (see appendix).
Measurements can be made on static or rotating rolls of containerboard, but as the instrument measures the moisture content of the outer 50 mm of the roll, this amount should be removed before a reading is taken.
Measurements are significantly affected by roll temperature, with elevated temperatures (fresh rolls) yielding high results and cold rolls (outside storage) yielding low results. If it is necessary to measure the moisture content of hot or cold rolls, calibration curves can be prepared, and used in conjunction with a temperature sensing device.
By moving a hand held moisture meter across a roll, and recording the moisture content at specific locations, it is possible to obtain a cross direction moisture profile.
By measuring the moisture at specific times as the roll unwinds, it is possible to obtain a machine direction moisture profile.
| Number of Pages : | 3 |
| Published : | 01/01/2003 |
