On-Line Moisture Measurement

On-Line vs. Other Types of Moisture Measurement

On-Line moisture measurement is the measurement of choice for many industries for very good reasons. While it may not be the best choice in all instances, understanding how On-Line works in comparison with other moisture measurement methods quickly shed light on why it is, often, the best method for accurate measurement.

When making a laboratory moisture measurement you must first assign laboratory personnel to periodically visit the process line to gather product samples. The personnel must be fully clothed in the necessary PPE, collect samples in approved sample containers, seal properly, and transport back to the lab for the test to begin. The test itself often looks like: Tare-weigh sample container, weigh sample and container carefully on 4-place digital scale, place in hot oven (usually 100 deg. C) for an appropriate drying time (usually 2-6 hours), remove the dried sample from oven and place in a desiccator to cool to room temperature, reweigh sample and container, subtract container weight, calculate moisture percentage via formula (wet weight minus dry weight divided by wet weight x 100. Be sure that sample size, oven temperature, and drying time are appropriate for each product or formulation

After the test is completed, the moisture percentage is then communicated to the process operator so the appropriate temperature/line speed changes can be made to achieve the target moisture level. The above process then must be repeated every 15 to 30 minutes for the duration of every shift.

Take that process in comparison with a handheld moisture measurement which requires the training and assignment of plant personnel to use the portable moisture meter. Then, clothed in appropriate PPE, they must visit the process line periodically and place the correctly-calibrated, handheld moisture meter on the processed product. From there, the moisture content measured must be reported to the process operator so the necessary changes can be made. Similar to lab measurements, the process must be repeated every 15-30 minutes to assure that the moisture limits are being achieved. Furthermore, records must be maintained of each test for production reports.

Bring in the On-Line Meters

Now, let’s compare those first two measurement methods to utilizing an On-Line moisture meter to receive and adjust in real-time.

First, you must calibrate the on-line, continuous NIR moisture meter. The calibration only needs to happen once. Then, you place the readout console or digital display where the operator can see continuous moisture results. Adjustments can be made as soon as an unwanted change in the process line occurs, and the built-in reporting package with Finna Sensors NIR solutions creates and maintains production records for you.

There’s no need for lab or process personnel to gather samples, vastly decreasing risk of staff injury. No need for expensive lab equipment or chemicals, no utility costs for eating ovens to high temperatures for extended periods of time. All of these things save on operating costs and overall budget, but these advantages only skim the surface.

Revolutionize Your Operation

The real benefit of on-line moisture meters comes from eliminating the possibility of out of spec product occurring between lab samples. A constant, controlled, set-point moisture measurement improved product quality across the board. It reduces or eliminates scrap, recycle, landfill transport, cleanup, downtime, possible operator overtime, utility costs for redo, regulatory plant emissions, and possibly even late customer shipments.

To put it simply, NIR, on-line moisture measurement can revolutionize your entire operation.