There are many models of wood moisture meters on the market. Their cost varies widely. In any case, the costs of purchasing a device are not commensurate with the risk of losing time, money and nerves from purchasing low-quality building materials or raw materials. If you are planning a construction project or starting your own business related to woodworking, you must stock up on a hygrometer!
Rating of the TOP 5 best moisture meters for wood: types, characteristics, reviews
In the production of products from wood material, it is important to take into account the moisture level of the raw materials, which can be determined by a special device - a moisture meter. Such compact devices use a non-contact operating principle.
They give a significant error when measuring hot materials and areas with a resinous surface. To make it easier for you to navigate this area, we have compiled a rating of the TOP 5 best moisture meters for wood: types, characteristics, reviews will be discussed in the article below.
The market for such devices is large: from small compact moisture meters to huge devices with many different functions. Let's look at the two most popular types.
- Needle (contact) Designed for extremely accurate measurement of the moisture level of various lumber and wood products. Determination of humidity occurs by measuring and converting the electrical resistance of the material under study into a percentage using the conductometric method.
- Contactless. Designed for high-precision determination of the moisture level of wood products using the dielcometric method. The measurement takes place in several stages: the type of species is set on the device, it is leaned against the surface of the wood, a button is pressed and the measurement result is displayed on the indicator.
Needle moisture meter
The conductometric measurement method is used - the device measures the current flowing between electrode needles embedded in the wood. The circuit of the device is simple, it includes: a power source, pointed electrodes, the current in the circuit is measured with a microammeter. Electrode needles have sizes from 15 to 25 mm, are made of hard metal, and are covered with a protective cover when not in use. The distance between the electrodes is determined by the device developers.
"ADA ZHT 125"
The device determines the moisture content as a percentage, the result is reflected on the display and does not require recalculation. The duration of one change does not exceed 5 seconds. A feature of contact models is their limited range of application: maximum accuracy is achieved at humidity from 7 to 30%; at higher values, the error increases significantly. The accuracy of measurements using needle moisture meters is influenced by the type of wood. It is recommended to use for measurements on wood that has not been subjected to chemical treatment.
"SEM DT-125H"
The rules for determining the moisture content of lumber using conductometric moisture meters are established by GOST 16588-91 and are consistent with the ISO system of international standards. Measurements are taken in different places of the workpiece: the first - at a distance of 0.5 m from the end, the subsequent ones - every linear meter. The needles are inserted vertically over their entire length; the line connecting the needles must be parallel or perpendicular to the wood fibers. The device is widely used when working with lumber: boards, beams, block houses, which do not lose their presentation after piercing.
The TOP 3 popular models include:
- "MEGEON 20502", Russia,
- "ADA ZHT 125", Hong Kong,
- "SEM DT-125H", China.
Rating TOP 5 best moisture meters for wood
Having analyzed the entire market of available goods, we have compiled the following rating:
Let's consider each model separately.
CONDTROL Hydro Pro
Microprocessor model of a moisture meter designed for measuring temperature and humidity in rooms, as well as monitoring wood moisture content in accordance with GOST. This compact model contains the functions of three different devices, while all sensors are built into the body. The device has two measurement modes: HOLD - fixing a single value, SCAN - for continuous scanning and detection of areas of high moisture content. In addition to measuring wood moisture, the device is suitable for concrete, mortar screed, plaster and brick.
| Error | 2.5% |
| Operating temperatures | from -5 to +40°С |
| Weight | 200 g |
Price: from 13,900 to 15,999 rubles.
- three operating modes (AUTO, HOLD, SCAN);
- small dimensions (145x60x35 mm);
- wide angle of object capture (up to 110°).
- not detected.
I decided to get into the wood trade and purchased this model to avoid various unpleasant situations. The package included a device passport, a humidity equivalent and a portable bag (convenient and practical). There is an automatic shutdown system, which allows you to significantly save electrical charge and prolong the operation of the equipment. I can’t highlight anything else. Simple, outstanding design, compact size. Overall I'm happy with the purchase.
CONDTROL Hydro-Tec
The model is designed for operational measurements of the moisture level of wood and other building materials. The principle of its operation is based on the correlation dependence of the dielectric constant of a material on its moisture content at positive temperatures. This makes it possible to perfectly accurately determine the moisture content in wood ranging from 2% to 65% at a depth of up to 20 mm. Despite its small size, the device contains a library that includes twenty types of wood: spruce, poplar, aspen, pine, cedar, linden, walnut, elm, maple, beech, pear, oak, cherry and others.
| Error | 2% |
| Operating temperatures | from -5 to +40°С |
| Weight | 75 g |
| View | contactless |
Price: from 4,300 to 5,990 rubles.
- about twenty lumber are stored in memory (oak, birch, maple, etc.);
- optimal error value (up to 2%);
- large display (5.5x12.3 cm).
- inconvenient housing (rubber braided).
As a person who often works with wood, it is important for me that the source material has a moisture content of no more than 10%. This is required, since this parameter cannot be determined by touch, and if you place a raw workpiece, the turned glass or bowl will inevitably crack and become irreparably damaged. This device allows you to quickly and accurately determine the level of moisture content in wood of various types of wood (aspen, linden and others). I'm happy.
TESTO 606-1
TESTO 606-1 is capable of determining the moisture level of almost any material, including wood. The device displays the obtained values as a percentage by weight, using characteristic curves for different types of wood and building materials. The HOLD function allows you to easily read the measured results from the device display. The model itself is compact, fits comfortably in the hand and looks quite original. There are two “antennas” on top, and in the center there are three buttons: a switch, the mode used, and backlight control.
| Weight | 230 g |
| Error | 1% |
| View | contact |
| Operating temperatures | from -40 to +70°С |
Price: from 8,390 to 9,500 rubles.
- bright display backlight;
- minor error (1%);
- withstands various temperature fluctuations (from -40 to +70°C).
- not found.
I recently came across this amazing device. It’s good that I managed to buy it quickly, since there were already less than nine of them left in the store. The unit runs on alkaline batteries with a maximum service life of up to two hundred hours. All measurement data is displayed on a liquid crystal screen with blue backlighting and high resolution. The device itself is lightweight, compact (fits in your pocket), but it has simply enormous functionality and even has built-in memory.
CEM DT-125H/G
This model of moisture meter is used to carry out operational measurements of the moisture content of building materials such as wood and concrete. Despite its compact dimensions, the device has a large menu containing twenty different types of wood. It has proven itself to be the best among carpenters, furniture makers, door and window manufacturers. The level of absolute error of the device does not go beyond the bar of 0.5%. Long battery life of the device (up to 10 hours) is provided by three AAA batteries. A convenient display and ergonomic push-button control distinguish this product from the rest.
| View | contact |
| Error | 0.5% |
| Operating temperatures | from -20 to +40°С |
| Weight | 172 g |
Price: from 4,520 to 5,120 rubles.
- long battery life (up to 10 hours);
- optimal LCD display size (4.4x12.2 cm);
- high measurement accuracy (up to 0.5%).
- not found.
The CEM DT-125H hygrometer does not require specific batteries: install three AAA batteries and use it actively for more than half a day. The device is compact, fits comfortably in the hand, and does not stand out in appearance. The measurement error is extremely low - no more than 1%. You can also measure the air temperature. All actions are carried out using the contact method, since this is the most accurate and reliable method.
GMH 3830
GMH 3830 is a universal probe meter with an electronic GSG 91 sensor. It is used to measure moisture in lumber and concrete at a depth of up to 50 mm. The device’s memory is already loaded with 16 different types of wood: beech, oak, spruce, cedar, maple, linden, walnut, aspen, fir and others. There are two high-precision measurement channels: humidity and temperature. Three levels of situation assessment: wet, damp, dry. The GSG 91 sensor has a plastic shockproof handle. Compatible with metal probes of 20, 30, 40, 60 mm.
| Weight | 170 g |
| Error | 2% |
| View | contact |
| Operating temperatures | from -25 to +50°С |
Price: from 27,800 to 37,200 rubles.
- light weight (170 g);
- large screen (7x5.8 cm).
- not found.
I purchased 30 of these devices for my small company on sale. They were purchased three years ago, but still function perfectly to this day. The delivery set included: the device itself with sensors, a connecting cable, replacement needles, a tube with conductive liquid, a packaging case and a manual for use. It’s not difficult to master working with it; a couple of minutes will be enough. The appearance is simple, similar to a cash register. There is a special antenna on top, trademarks on the bottom, and control buttons in the center.
How to independently determine the moisture content of wood, or 10 models of household moisture meters
With the onset of spring, many will resume construction of houses, including frame and wooden ones. Over the long winter, the natural material could become damp, and this is fraught with warping and cracks. A portable moisture meter will help determine the condition of wood.
During the times of “historical materialism”, the moisture level of wood was determined according to GOST. This was a long and laborious process that required strict adherence to all research algorithms. But with the advent of portable moisture meters (hygrometers), the problem was solved. Now the condition of the wood can be determined in a few seconds.
The optimal moisture content of wood for construction is on average 6-14%. It is better not to use damper material: when drying, it will warp
A moisture meter is a small device in a plastic case. The device determines the moisture content of wood indirectly, based on its electrical resistivity. This indicator varies depending on the amount of water in the body of the material. Special sensors record readings obtained upon contact with wood, and a microprocessor processes them and displays the data on the display. The device does not depend on the electrical network - batteries or an accumulator are enough to provide energy.
In addition to their main function, improved moisture meters can also determine air humidity and temperature, which makes it possible to assess the storage conditions of lumber. Of course, such a device is more expensive than a regular one, but the costs are worth it. After all, if you notice in time high humidity or sharp temperature fluctuations in a warehouse where expensive wood is stored, you can prevent its damage.
The latest models of moisture meters can transmit information wirelessly to a computer
It is important to note that even the most advanced moisture meters operate with a certain error (from 0.5 to 4%). There are several reasons for this. First of all, this is the locality of measurements. The tree trunk is unevenly saturated with moisture, which means that the board cut from it will have more or less wet areas. Also, the inaccuracy of measurements is due to the fact that different species have different densities: the denser the wood, the drier it is. High resin content can also affect the readings of the device.
However, the error of household moisture meters is completely insignificant. Their reliability is quite enough to work with wood at the household level. And high-precision (and very expensive) devices are used mainly in woodworking factories.
Features of choice
An important characteristic of a moisture meter is its measurement range. Some models are capable of detecting humidity on a scale from 0 to 100%. But devices with a narrow range are more accurate and productive, as they are designed for less data processing. In addition, a wide measurement range is more important in the professional field. For a simple user, readings in the range of 1–50% are sufficient.
When choosing a device, it is useful to consider a set of additional functions. Often, even relatively inexpensive household moisture meters can save data into memory, keep measurement statistics, automatically turn off in case of long inactivity, etc.
And of course, the buyer needs to understand the types of devices. There are two main types of moisture meters. Let's start with the most common one.
Contact (needle) moisture meters
Devices of this kind are equipped with needles (probes), which are inserted into the wood during measurement. The device passes current between them, determines the resistance of the medium and displays the readings on the screen.
The moisture meter spikes can be located on the body or on a separate “plug” connected via a wire. When measuring, it is stuck into the body of the board. This provides more accurate readings (after all, the wood is drier on the outside than on the inside). Although such devices are more expensive than conventional ones.
Thanks to the remote sensor, wood moisture measurements can be taken in hard-to-reach places
Contact moisture meters are structurally simple, so they rarely fail. With intensive use, the needles may break, but they are easy to replace. Some manufacturers include several spare pairs with their devices.
Continuing the conversation about the advantages of needle moisture meters, it is worth noting their compactness, fairly high measurement accuracy, ease of use and affordable price (on average 1000-5000 rubles). Of course, this does not apply to professional models - their price is tens of thousands of rubles.
Well, the main disadvantage of needle moisture meters is that when measuring, they still damage the material, albeit a little. This is especially unpleasant if you need to determine the condition of expensive valuable wood or a finished product.
However, for carpentry, plumbing and turning work at the household level, a contact moisture meter is almost ideal. Let's give a few examples of what the market offers us.
#yad#Simple and compact moisture meter KWB 0121-00
will cost the user only 2100 rubles. The device determines wood moisture content in the range from 0 to 30%. After 30 sec. After inactivity, it automatically turns off to save battery.
Another budget model - MEGEON 20610
. Its price is also 2100 rubles. But there are several more possibilities than the moisture meter described above. It is able to detect temperature and humidity. The display has additional backlighting, which allows you to work in relatively dark rooms. But the main distinctive feature of the device is the ability to configure it for 4 types of wood species.
Device MD814
for 3000 rub. measures wood moisture content in the range from 5 to 40%. The error is 1%, the step is 1%. The measurement operation time is only 2 seconds. The device operates smoothly at temperatures from 0 to 40 °C.
More expensive (about 5,000 rubles) professional moisture meter CEM DT-129
480229 is equipped with an external probe. The eight-digit calibration scale allows you to accurately measure the condition of wood from 150 species. When inactive, the device automatically turns off after 5 minutes.
Professional wood moisture meter HygroLiner MWP-70
(RUB 8,000) with an external sensor effectively measures wood in four groups, based on the individual characteristics of the species.
The maximum humidity level is automatically recorded in the device memory. In addition to humidity, the device can measure sample temperature in the range from −10°C to +60°C with a resolution of 1°C and an error of no more than ±2°C.
And the list of examples of needle devices TESTO 606-1
worth 8,000 rubles. The device is designed to assess humidity at a depth of up to 2 cm. Humidity measurement range: for wood - 7–54.8%, for building materials 0–22%. Autonomous operation from up to 200 hours. The scale for 7 groups of building materials allows you to achieve the most accurate readings of the device.
If the moisture meter needle is damaged, the fragment must be pulled out of the wood. Otherwise, during further mechanical processing of lumber, expensive tools and equipment can be damaged.
Non-contact (dielkometric) moisture meter
A less common type of moisture meter is the non-contact one. However, this name is not entirely correct. When measuring, touching the wooden surface is still necessary. Only the working part of the device is not needles, but special sensors that do not damage the wood. They are usually located on the rear panel of the device, but there are also models with a remote measuring cylinder.
Some models of non-contact moisture meters provide scanning at a depth of up to 50 mm
Non-contact moisture meters are very useful when working with valuable types of wood, and in other cases when damage to the material is unacceptable. But at the same time, they usually cost more than needle ones. In addition, these devices are characterized by a rather large measurement error, especially on resinous wood. Finally, they require a smooth surface on the test piece. They cannot properly measure an unplaned board.
Still, non-contact moisture meters are popular and occupy a fairly large market segment. Here are some interesting models.
Humidity meter and thermometer ZHT 60
used both in everyday life and in the professional sphere. It allows you to measure the relative humidity of wood and other materials in the range from 0% to 100%, as well as temperature from 0 ° C to 60 ° C. The received data can be saved in the device memory. Its price is 2500 rubles.
ADA
ZHT 100 6 in 1 A00400
. This is a compact, simple and relatively cheap (about 3,400 rubles) model that measures the humidity and temperature of various materials and air and is extremely easy to operate. Equipped with a backlit LCD display. To save batteries when inactive for more than 10 seconds. The backlight turns off automatically, and after 20 minutes. - the device itself.
Moisture meter CEM DT-128M
costs more than 5,000 rubles, but its capabilities are wider. It is capable of storing the received readings, as well as displaying the minimum and maximum values. The device has a charge indicator. The depth of measurements varies in the range of 20-40mm
The even more expensive (about 6,000 rubles) CONDTROL
Hydro- Tec
has many more useful options. This professional moisture meter is capable of measuring the moisture content of 23 types of wood with different characteristics, as well as other materials - brick, plaster, concrete, etc. The maximum measurement depth on wood is 20 mm.
Concluding the topic, we note that for the most accurate moisture meter readings, it is advisable to take several measurements and calculate the arithmetic average. Some devices can do this automatically.
Comparison table of characteristics
For a more clear comparison of the models presented above, we have compiled a comparison table.
| Model | View | Accuracy (%) | Operating temperatures (°C) | Weight, kg) | Price, rub) |
| CONDTROL Hydro Pro | contact | 2.5 | from -5 to +40 | 200 g | from 13,900 to 15,999 |
| CONDTROL Hydro-Tec | contactless | 2 | from -5 to +40 | 75 | from 4,300 to 5,990 |
| TESTO 606-1 | contact | 1 | from -40 to +70 | 230 | from 8,390 to 9,500 |
| CEM DT-125H/G | contact | 0.5 | from -20 to + 40 | 172 | from 4,520 to 5,120 |
| GMH 3830 | contact | 2 | from -25 to +50 | 170 | from 27,800 to 37,200 |
How to use it correctly?
Despite the fact that these devices always come with instructions for proper use, some people cannot always correctly interpret the information described in the instructions for use. Now we will explain everything clearly to you.
Let's say you need to determine the moisture level of a parquet board. In this example, it is better to use a non-contact model; it will not harm the finished product. So, the measurement process goes like this:
- The board itself is prepared (cleaned of debris, it is advisable to ensure a flat surface).
- The device turns on (the button on the device itself).
- The calibration is set (according to the table in the instructions).
- The moisture meter is brought with the sensor side to the surface of the board or inserted into it.
- The display shows the measurement results we need.
What to look for when choosing
Let's consider what criteria should be taken into account in order to make a successful purchase.
- When choosing a moisture meter, the main criterion is the type of unit. There are two types: contact and non-contact.
- Contact (needle). Equipped with small metal needles, which must be immersed in specially prepared holes in the product. After this, the device will begin to create electrical resistance between the needles and the material. Working with this type is quite simple, but the product being tested suffers.
- Non-contact (dielcometric). Created on the basis of a radio frequency generator, which allows you to get a fairly accurate result. The device does not affect the quality of the product being tested.
- Cost of the device. Don't buy an overly expensive model. Their work follows the same principle, which means it makes no sense to overpay for a model whose manufacturers are simply luring buyers.
- Size. The comfort of use depends on the size of the device. Pay attention to the medium-sized model so that it fits easily in your hand. Otherwise, what is the use of a device if it cannot be used?
Needle meters
The contact method of deep humidity measurement is carried out using needle devices, the action of which is based on the conductometric determination of the electrical conductivity of the object of study.
Rigid thin metal needles are introduced into lumber and wood raw materials, which record the value of electrical resistance. The value is converted into a humidity indicator, which can be immediately seen on the display.
To obtain completely reliable information, the result must be checked with the special attached tables that take into account the influence of the medium temperature on the measurement accuracy.
Note! Needles cause minor damage to the object, so this moisture meter should not be used for veneer or finished wood products.
To examine wooden boards, moisture meters with short needles are often used, which allows some marketers to present the devices as surface devices. In fact, they are not, because the defining elements are the needles inserted into the wood. The depth of surface damage when taking measurements with such a device is less than when using a conventional needle device.
Conductometric determinations make it possible to record moisture concentrations whose values are greater than 5%. To study objects with a lower concentration of water molecules, you need a high voltage source with characteristics from 500 to 1500 volts, which is impossible to achieve when using portable moisture meters.
Introduction
Why do you need to choose a meter at all? Well, I bought the first one I came across for the tree and that’s it! But no, friends, that won’t work. Some moisture meters give a large error on warm or hot lumber, others are very bulky and heavy, and others can only measure the surface of the board without measuring the moisture content inside.
As you understand from the above, each type of meters has its own task. And based on the functions you need, you need to choose a moisture meter. Now I will describe the functions, and it’s up to you to decide on choosing one or another meter.
Challenges for measurers
In addition to different raw materials, these devices also perform different tasks, let's look at the most common tasks:
- Quick approximate moisture check on boards without mechanical damage to the material;
- Qualitative inspection of lumber;
- Continuous monitoring of the drying process in drying chambers;
- Inspection of hot lumber;
- Quickly check the water content of hot and cold chips;
- Flow control of hot chips;
- In-line precise control of cooled chips.
And this is not the full range of products and tasks that measurers face. That is why there are so many different types of moisture meters and modifications. I propose now to consider all types of moisture meters and the tasks that each type performs.
Types of humidity measuring instruments
For all of the above tasks, manufacturers began to make the following devices.
Laboratory
Such instruments are used to test the water content of shredded wood. Their accuracy is quite high, which is facilitated by very precise scales (up to 0.001 g). Such devices in Russia are manufactured under the EVLAS brand in the city of Novosibirsk. We had their device in our laboratory.
It shows good results for the first six months, and then it needs to be repaired, and so on every year.
Therefore, I will not recommend it to my readers.
Contactless portable
Used to check moisture without damaging wood. The disadvantage is that they are quite unstable to measuring hot materials and there is a large error in measurements.
In addition, areas with increased resin content of boards after drying are measured poorly. They are used in the production of molded products and spliced products, in places where damage to the material is unacceptable.
Needle portable
Portable moisture meters can be of several types:
- For boards, compact pocket ones with a short needle. Their advantage is mobility; the master can always carry it in his pocket. Flaws, moisture checks on the surface of the board and small marks remaining on the finished product. Judging by the reviews and taking into account my experience, we can say that these are the optimal devices for measuring boards. They are compact and precise;
- Less compact and more bulky depth measuring devices with a mechanism for driving needles into thick boards. In my opinion, these devices are the most accurate, since they can measure humidity in the central part of the board. The disadvantage is that the needles in the board often break; this is unpleasant, especially in cases of unfair use of the device. For example, they measured the humidity, broke the needle and did not pull it out of the board. Then very expensive tools break down on a four-sided machine.
Portable for bulk materials
Here you can find two types of meters:
- Contactless, like their other counterparts, have measurement errors;
- Needle deep. These are quite good for measuring the moisture content of wood chips in piles.
Non-contact in-line stationary for chopped wood
Non-contact flow meters are more commonly used to measure chip moisture. Used in the production of particle boards, MDF, OSB. Installed above chip conveyors.
They are divided into:
- Ultraviolet. They provide maximum measurement accuracy, but show negative results with warm or hot chips;
- Microwave. Less accurate than ultraviolet, but more resistant to changes in chip moisture.
Needle stationary
Such devices are used in drying chambers. They differ from portable ones in that they are used constantly. Based on their readings, the stages of the drying process in the drying chamber are switched.
Additional features
Some meters have a function for measuring air humidity. This parameter can be used to check the water content in the environment in the raw material storage warehouse, drying chamber, workshop and finished goods warehouse. A device with such bells and whistles may cost more, but often the function justifies itself.
Another function is to determine the ambient temperature and air temperature. Useful for monitoring the process in the drying chamber.
Function for calculating the average value. As a rule, to accurately measure the presence of water in wood, you need to take several measurements and calculate the average value. Some manufacturers have introduced a function for calculating average humidity for their devices.
DIY psychrometer and moisture meter for wood
When equipping a carpentry workshop, it is necessary to know the air humidity in the room and be able to control the quality of raw materials. You can make devices to monitor these parameters with your own hands.
The simplest psychrometer is a device for determining air humidity, which can be made within 30 minutes. To do this, you need two ordinary room alcohol thermometers. Thermometers can be placed on the wall or on a special stand. The main condition is that for one thermometer, the expansion flask with alcohol must be wrapped in a damp cloth. Thermometer readings will be different: the drier the surrounding air, the lower the temperature the “wet” thermometer will show. As air humidity increases, the difference in readings will be less. More accurately, the humidity in the workshop can be determined using a special table available on the Internet.
The Internet offers many schemes for making moisture meters with your own hands. If you calculate the cost of components, the cost of homemade products will be comparable to the cost of the simplest industrial designs. Experienced craftsmen do without moisture meters and determine the moisture content of wood by indirect signs: by the color and elasticity of the chips, by sound - when hit with a carpenter's mallet, dry wood makes a characteristic ringing sound, and other signs.
conclusions
As was said, you need to select your own meter for each condition.
My recommendations are to always keep two or even three meters in production to determine moisture in wood, which allows you to keep readings from other moisture meters if one fails.
Many beginners forget about adjusting the moisture meter and choosing the type of wood in it, this leads to an error.
Good luck and see you again, Andrey Noak was with you!
Probes for depth measurements
Moisture meters with probes make it possible to determine the mass fraction of water at great depths in the material at concentrations exceeding 5%. The device generator produces a signal with a frequency of 20 MHz. Sensitive elements record changes in resistance in the material, which makes it possible to determine the dielectric constant of wood at a large distance from the surface. The device is effective for measuring the moisture content in thick products, bulk piles of shavings or sawdust.
We study the tool: moisture meters for wood and the nuances of their use
Wood is an environmentally friendly material, in demand in the construction of various types of objects, at all stages of construction and installation work, as well as in the manufacture of furniture and interior items. To determine the quality of wood, there are special instruments and devices that facilitate the implementation of work on incoming control of raw materials and compliance with production technologies for products and blanks made from wood. Moisture meters for wood - types and descriptions of popular models, how to choose, as well as an overview of prices for the most popular models, this is the topic of this article.
Purpose and types
A moisture meter is an electronic device designed to determine the moisture content as a percentage of the mass of the object being tested.
According to their purpose, such devices are classified as follows: for wood and bulk materials, for soil and soil, as well as other building materials.
For your information! Moisture meters for bulk materials are in demand in the food industry and agriculture, for soil and soil - when optimizing the microclimate in greenhouses and other activities related to various types of agricultural technology. Instruments used in construction make it possible to control the quality of bricks and concrete, as well as compliance with the technology of finishing and installation work.
Moisture meters for wood are used in woodworking and processing enterprises, in furniture and construction industries.
Based on their design, moisture meters are classified as follows:
- needle - have two sharp electrodes that are immersed in a wooden surface, after which a measurement is performed;
- non-contact – they work without immersion in the material being tested; for this, just touching it is enough;
- surface measurement - similar in design to needle models, but differ in that when they are used, the needles of the device are only slightly immersed in the surface of the material being tested;
- depth measurement - massive instruments for professional use, when examining large volumes of lumber, sawdust and products made from them (fuel briquettes, pellets, etc.).
For your information! The operation of a moisture meter is based on measuring the resistivity of the material being tested when an electric current passes through it.
Needle moisture meters for wood
Needle models, called conductometric devices, are calibrated for specific types of wood that differ in their resistivity.
When an electrical pulse passes, the meter compares the readings contained in it for a specific type of wood with the result obtained, which is reflected on the display.
The advantages of devices of this type are the following indicators:
- ease of use;
- high measurement accuracy;
- relatively low cost.
Disadvantages are also present, these include the following indicators, such as:
- during measurements, the surface of the material or product being tested is damaged;
- the measurement limit does not allow measuring humidity when its level is below 4%.
Non-contact moisture meters for wood
Devices operating on a non-contact principle have a radio frequency generator in their design; they are called dielectric moisture meters.
When using devices of this type, it is necessary to apply a special contact surface to the measurement object or move it to a certain distance, which depends on the model of the device and the type of measurements being performed.
The advantages of meters of this type are the following indicators:
- the wood is not damaged during measurements;
- low percentage of error in the results obtained;
- The presence of memory makes it easier to use when taking measurements.
Disadvantages include high cost and the inability to carry out repairs on your own.
Using a dielcometric model when checking the moisture content of board materials (chipboards)
Purpose of moisture meters
A wood moisture meter is used at logging enterprises in the manufacture of wooden products. The quality and value of the raw materials themselves and the products that are made from these raw materials depend on the moisture content.
The level of quality of manufactured wood products, from a chair to a log house, directly depends on the amount of moisture contained in the wood. This parameter is variable and depends on the season of procurement of raw materials, conditions and time of storage. An enterprise whose activities are aimed at supplying, storing and harvesting wood must have special hygrometers to control its humidity. Craftsmen who work with wood will also benefit from such a device.
Accurate determination of wood moisture content is only possible using laboratory analysis. To do this, an “average” sample is taken from a batch of lumber; in the laboratory, pieces of wood are placed in a drying oven and dried to a constant weight. The difference between the initial and final mass is used to determine the percentage of moisture content in a given sample. The advantage of this method is the highest accuracy. There are many more disadvantages of determining humidity according to GOST. First of all, this is the duration of the analysis. The process may take several days. In addition, to measure the moisture content of wood according to the method, you need to separate a piece of wood, so this method is unacceptable for finished products.
You can replace time-consuming analysis in the laboratory with a simple and quick measurement using an electronic moisture meter. The small device provides reliable results instantly. The principle of operation and assessment of water content with a moisture meter is based on measuring the electrical resistivity of wood, which directly depends on the moisture content of the material.
A moisture meter determines the moisture content of wood as a percentage. Measurement using this method has a small error of 2-10%. Such a deviation from the true value can occur for several reasons:
- Local dimension. This error is reduced by increasing the number of measurement points and then calculating the average result.
- The nature of wood. Wood of different tree species has different electrical conductivity, which also introduces error into the measurement.
Advantages
A moisture meter used for wood has many advantages:
- Non-destructive measurement method. There is no need to saw off a piece of lumber or product.
- Easy to use. The measurement does not require any physical force.
- The temperature of the measurement object and the surrounding air do not affect the operation of the device.
- Convenient to use, which is especially important in conditions close to field conditions (sawmill, construction site).
- Low cost with high sensitivity and measurement accuracy.
How to choose a moisture meter for wood
When choosing a specific device model, the main parameter that you should focus on is the range in which measurements can be performed.
For your information! Devices capable of operating in a wide measurement range (from 0 to 100%), as a rule, are able to take measurements with greater accuracy than models operating in a smaller range.
In addition to the main parameter, the selection criteria will be the following indicators:
- to measure the moisture level of wood, what type of device will be used - raw materials, lumber, furniture, etc.;
- nature of use - periodic or regular, which depends on the type of production and its volume;
- instrument error;
- overall dimensions and weight;
- reliability;
- price.
Based on the selection criteria, a specific device model is selected. Fortunately, there are quite a lot of models of domestic and foreign production on the market for such equipment.
Using a surface-type device to measure the moisture content of lumber
Dependence of wood quality on its moisture content
The moisture content of wood and other materials means the percentage of the weight of the moisture they contain to the weight of 100% dry material. A freshly cut tree cut has indicators from 60 to 90%; such fluctuations depend on the month in which the tree was felled. In addition, humidity changes over time depending on the specific tree species. Freshly cut wood is unsuitable for carpentry work due to its high humidity.
For construction work, the wood must be dried to 10-15%, while for the production of high-quality furniture you will need material with indicators of 8-10%. The level of moisture in wood greatly affects its physical and mechanical properties. For example, if the humidity is too low - below 4% - then under the influence of water thin films are formed in the wood structure, as if splitting the tree from the inside. In this state, the lumber becomes brittle and easily crumbles. However, in this state, wood is able to greedily absorb not only moisture, but also various binders and other ingredients used when working with wood. In turn, humidity above 15%, on the contrary, will resist the penetration of those same ingredients into the wood material. Thus, it is best to bring the moisture content of bulk wood waste to average values - around 10%.
Review of popular models
As already written above, the domestic market offers a fairly wide selection of models of moisture meters from Russian and foreign manufacturers. In this section of the article we will talk about some of them.
"Control Hydro Pro"
This model is a Russian development, its main technical characteristics are given in the table below:
| Device type | Measurement limit, % | Weight, gram | Operating temperature range, °C | Measurement error |
| Contactless | 2,0-65,0 | 200 | +4,0 – +40,0 | 1,0 |
The cost of the model according to Yandex.Market as of the third quarter of 2021 is:
"EM4806"
This model is produced (Germany), its main technical characteristics are given in the table below:
| Device type | Measurement limit,% | Weight, gram | Operating temperature range, °C | Measurement error |
| Needle type | 6,0-42,0 | 50 | +0 – +40,0 | 2,0 |
The cost of the model as of the third quarter of 2021 is 1,500 – 2,000 rubles.
"GMH 3830"
The model is produced by GREISINGER electronic GmbH (Germany), its main technical characteristics are given in the table below:
| Device type | Measurement limit, % | Weight, gram | Operating temperature range, °C | Measurement error |
| Electronic, universal | 3,0-100,0 | — | -25,0 – +50,0 | 0,2-2,0 |
The cost of the model according to Yandex.Market as of the third quarter of 2021 is:
"SEM DT-125N"
The moisture meter is made in China, its main technical characteristics are given in the following table:
| Device type | Measurement limit, % | Weight, gram | Operating temperature range, ˚С | Measurement error |
| Electronic, universal | 6,0-99,9 | 0,175 | -35,0 – +85,0 | — |
The cost of the model according to Yandex.Market as of the third quarter of 2021 is:
