5 Tips for Measuring Cotton Moisture with a Wood Moisture Meter
Tip #1: Use a moisture meter
When harvesting dozens of acres of cotton (or more), manual testing methods for checking cotton %MC are impractical. A simple touch test does not provide a quantifiable measurement of cotton moisture content.
Oven dry tests, which are highly accurate if done correctly, take too long to complete in order to measure moisture in cotton in time for harvest or ginning. By the time you get a measurement from enough cotton samples to say you know exactly what the moisture content of the cotton is, the rest of the cotton may have seen a significant change in %MC!
Moisture meter cotton, on the other hand, can provide a reliable measurement of your cotton's moisture content in seconds, not hours.
Tip #2: When to measure moisture
Generally, the important time to measure cotton moisture is at harvest, when ginning takes place again. You can also check the moisture of your cotton before you sell it to indicate how much of the cotton's weight comes from moisture.
Checking the moisture before passing the cotton through the gin ensures high quality long fibres by letting you know if the cotton needs to be dry or wet. Checking for moisture during the selling process lets your buyers know they are getting a fair market price and won't be charged for too much water.
Tip #3: Choose the right electrode for the job
Cotton comes in many different forms at different stages of the harvest. From lint and seed cotton to large, fluffy white bales, it's important to have the right measuring equipment for the job.
When you need to test for moisture in lint or seed cotton, a small cup electrode such as the 52-E/C electrode may be the better type of electrode to use. With this electrode, you simply place a sample of cotton into the cup, press it firmly down with your finger (even if the sample still overflows the cup thereafter), and press the read button on the moisture meter.
It is important to remember that tests carried out on seeded cotton may not be as accurate as the lint test. This is due to the presence of seeds in the cotton that may have a higher moisture content than lint, as well as the randomness of the number of seeds in any given sample.
In order to test cotton bales, you need to use an extension electrode to penetrate the inside of the bale in order to test for moisture.The 30-E/C electrode is ideal for this purpose because it has two insulated pins that are 24 cm (9 1/2 in) long. The insulation on the pins allows them to penetrate to the deepest part of the bale and give you a moisture reading at a specific depth, not the surface moisture on the bale.
In particularly tightly packed bales, a heavy-duty electrode made of steel may be needed to penetrate the bale to get a reading.
To measure cotton that has been processed into yarn, shorter electrodes with multiple contact points (e.g., 37-E/C) are more suitable for obtaining reliable readings.
Tip #4: Weighing Cotton Moisture
According to information cited by the U.S. Department of Agriculture, cotton has a moisture content of between 6.5 and 8 per cent when measured prior to ginning. When at that % MC, the quality of yarn processed from the cotton will be higher than when the cotton moisture content is significantly lower.
Cotton that is wetter than 8 per cent MC can easily stick to the machine, causing blockages that can hamper production or even destroy expensive equipment.
Tip #5: Check Meter Calibration
Properly maintained and serviced, well-made hygrometers from reliable manufacturers are tools you can rely on for years to come. However, it is still important to check the calibration of the meter regularly to ensure that you get accurate results.
