Equipment

The Different Types of Moisture Meters

Several moisture meters are available for solid materials, including bulk solids. Each one measures the moisture content differently, based on different measuring principles. Here are three of the most popular types. Resistance and Pin-type meters measure moisture content in solid materials, while Pinless meters are difficult to use. This article looks at the pros and cons of each type. To learn more, continue reading! We will cover the differences between the two types of meters and discuss their respective uses.

Pin-type meters are more sensitive to chemicals and minerals in the wood.

moisture meterThe resistance and dielectric properties of wood change in proportion to the moisture content. Resistance-type meters express the moisture content in per cent of the oven-dry weight of the wood. The measurement range for resistance-type meters is from the fibre saturation point (25-30%) down to about six per cent. However, readings at lower moisture content can be difficult because it’s difficult to determine the cause of the standing water.

A pin-type moisture meter is more sensitive to wood’s chemical and mineral content because they use two electrodes. These pins are placed in different places within the wood. A pin’s resistance increases with moisture, but it resists the electrical flow as the wood becomes drier. Resistance is measured in ohms, and the reading is converted into X% moisture content. These meters are more accurate than other moisture detectors, and they are the fastest and most accurate way to test wood.

Resistance-type meters express moisture content as a percentage of the oven-dry weight of the wood.

The electrical resistivity of wood varies with its moisture content. The electrical resistance varies from 7 to 30%, depending on the type of wood and its density. The density of wood also varies with different tree species. Therefore, an electric moisture meter’s resistance will vary depending on the temperature and density of the wood. The manufacturer of the instrument will have tables and embedded calculators to calculate the moisture content of the wood.

The electrical resistance of wood increases as it dries but changes as the wood gets closer to the fibre saturation point, usually about 30 per cent. It means that even a small change in the moisture content affects the resistance. Hence, some meters are calibrated to a higher moisture content level, while others have lower accuracy limits. In addition to the temperature, the resistance of some foreign woods is significantly higher than that of most domestic woods.

Pinless meters are difficult to use

Pinless moisture meters are easier to use than pin meters. The probes in pin meters require constant pressure to drive deep into the product. It means that operators tend only to drive the probes as deep as they feel comfortable. However, if you plan to measure large amounts of wood, it is best to use Kett dielectric meters. These meters can measure a large amount of wood in one go and have a large range of measurement accuracy.

The General Tools MM9 Pinless Moisture Meter features a pinless sensor that allows you to pinpoint high moisture areas. It can be very useful if you need to know where to start measuring the moisture content of a large area. The General MM9 moisture meter also features a pin mode for measuring actual moisture content. In addition, it comes with preset ranges for hardwood, cement board, softwood, and drywall. It also comes with a built-in calibration mode.

The microwave method is popular for determining moisture content in bulk materials.

The microwave method is a popular method for determining the moisture content of bulk materials. This method is based on reflection, and the signal’s mass per unit area is a function of moisture content. Hence, it effectively determines the moisture content in materials with a low attenuation factor. However, this method has some limitations. For instance, it is not reliable for materials with a high attenuation factor. Furthermore, this method only penetrates a thin layer of the material.

The measurement is performed by sending a microwave signal through the sample. The signal’s attenuation and phase shift are then measured. This difference in energy is proportional to the difference between the sample and the air. The microwave signal’s attenuation can be compensated by mass measurement, which an ultrasonic level or belt weigher provides. Alternatively, the sample’s density can be measured using a Nuclear Type Density Transmitter.