Company news

Moisture meter for drywall and other sheet materials on conveyors

December 5, 2022

FIZEPR-SW100.15.1 is a moisture meter designed for non-contact measurements of moisture content in drywall, fiberboard, chipboard, medium density fiberboard plates and other sheet materials on a conveyor line. This moisture meter can also be used to measure moisture content in timber.

The moisture meter sensor has an operating temperature of +180ºС, so it can be used in drying chambers.

The sensor contains stainless steel plates. These plates are secured on frames on the bottom and top of the controlled sheet, and gaps between the plates and the sheet must not exceed 1...2 mm.

Moisture meter operation is based on the dielcometric measurement principle, i.e. the capacitance of the capacitor formed by metal plates is actually measured. However, this solution has a significant feature: sensor cables connected to capacitor plates do not affect the capacitance measured.  

The second feature of the moisture meter developed is the volumetric measurement with the determination of the total water content in the controlled volume, i.e. the measurement result is equally affected by moisture concentrated in both sheets of paper (cardboard) applied on the front and rear parts of the panel and moisture concentrated in the gypsum core.

Since cardboard and gypsum have absolutely different water absorbing and electrical properties, then the volumetric measurement only can provide reliable actual moisture values.

Industrial drywall moisture measurements are made using five moisture meter types:

  1. Electric-resistance moisture meters with electrodes pressed against the drywall surface on one side of the drywall sheet
  2. Inductive moisture meters that also measure conductivity with the exciting coil pressed against the surface on one side of the drywall sheet
  3. Dielectric moisture meters containing planar electrodes that are also pressed on one side of the drywall sheet
  4. Optical (infrared) moisture meters that measure moisture content by the light reflected from the drywall sheet surface
  5. SHF (microwave) moisture meters with transmitting and receiving antennas placed on the opposite sides of the drywall sheet.

For moisture meters 1, 2, 3 and 4 with the one-side sheet probing, the above-mentioned factors lead to higher measurement error. 

Moreover, measurement results of moisture meters 1 - 3 are greatly affected by the size of the gap between the sensor and the sheet surface, so these moisture meters are not used for the automatic control of sheet materials on a conveyor line.

Moisture meter 5 (microwave moisture meter), at first glance, probes the drywall sheet through the entire thickness, but the reflected microwave signal is formed by the sheet surface near the transmitting antenna only. In addition, the boundary of transition from cardboard to this antenna also affects the signal coming to the receiving antenna, so moisture in cardboard affects measurement results to a greater extent than moisture in gypsum.

The figure shows an example of moisture meter installation in the drywall production line.

The electronic unit of moisture meter is located several meters away from the sensor.  Measurement results are transmitted to external indication and control devices via RS-485 MODBUS RTU interface with 4-20 mA current to distances of up to 1 km.

© Design Bureau Fizelektronpribor, Ltd., 2022.12.05

Measurement of moisture in crude oil with a high gas volume content

October 18, 2020

For all existing crude oil moisture meters, the metering error increases when gas appears in oil. For most of them, when gas volume content exceeds  2 - 5%, the metering error becomes unacceptable.

A solution has been found specifically for FIZEPR-SW100 series in-line moisture meters to ensure accurate crude oil moisture measurement even with a high gas volume content. The solution is shown in the figure.

This solution has become possible due to a large volume measured in the FIZEPR-SW100 sensors at a time. For example, the material volume controlled in FIZEPR-SW100.20.12 (DN80, PN63) sensors at once is more than 2 liters. Crude oil consisting of poorly mixed water and hydrocarbons is measured as a homogeneous mixture when such a large volume is analyzed.

This feature of moisture meters ensures a solution based on a sharp drop of the flow speed when the pipeline section is expanded. When the flow speed drops abruptly (the figure shows a version with a 30 times speed drop), the gas is separated: it is separated from the liquid and passes through a separate channel outside the moisture meter. It means that the crude oil flowing through the moisture meter is also stratified, but as shown above, this stratification has little effect on measurement results.

The proposed design is welded from standard pipe fittings: tees according to GOST 17376-2001 or TU 1469-001-82932963-2009 specifications, adapters according to GOST 17378-2001 and bends according to GOST 30753-2001. The total costs of the tees, adapters and bends made of 09G2S steel shown in the drawing do not exceed 68 thousand rubles.


March 15, 2019

The new series analyzers designed for measuring concentrations of salt, acid and alkali solutions is put into production. Analyzers can also be used as moisture meters, but they can also measure materials with high electrical conductivity, such as anthracite, sewage sludge, ion-exchange resins (ion-exchange polymer), etc. Analyzers are used for in-line control of materials as well as for measurements in tanks and laboratory studies.

Sensors of analyzers in the in-line version are made for working pressures PN up to 160 bar and nominal bore DN from 50 to 150 mm. 

FIZEPR-SW100.27.6 (DN80, PN16) analyzer

Concentration sensors shown in photos are the development of FIZEPR-SW100.20.х moisture analyzer series and made as a pipe with flanges. But these sensors can be manufactured in any version in which FIZEPR-SW100 moisture meters are made.

For example, the FIZEPR-SW100.11.6 analyzer can be used to measure concentrations of liquid and paste-like materials in tanks. The sensor of this analyzer contains a probe made as two parallel rods.  FIZEPR-SW100.11.6 and 11.41 sensors 



This sensor has a housing diameter of 48 mm and it can be used to control liquids in the measuring cylinder.

This sensor has a sealed design and can be secured on the pipe rod with the G1 straight pipe thread coupling. This sensor version can be used to control liquids in tanks including applications where wastewater sludge concentration measurements are required. Below is the calibration characteristic of a moisture meter for measuring sewage sludge. 


The FIZEPR-SW100.30.26 analyzer version replicates the laboratory version of the FIZEPR-SW100.30.2 moisture analyzer. The sensor is made as a measuring cell and can be used to analyze the composition of liquid, paste-like and bulk materials featuring high conductivity.

FIZEPR-SW100.30.26 analyzer









The operating principle of concentration meters manufactured by other companies is primarily based on measuring conductivity of the controlled material. However, instruments using this principle (conductivity meters) are not suitable for measurements at high conductivity. For example, the usable range of caustic solution (NaOH - sodium hydroxide) concentration standard for VALMET concentration sensors is limited by a value of 20%.

FIZEPR-SW100 analyzers have a substantially greater range of measurements. As shown in the chart, sodium hydroxide measurements are provided in the range up to 40% at temperatures over 100ºС.

Similarly to all FIZEPR-SW100 series moisture meters produced, new instruments have a radio wave measurement principle based on electromagnetic velocity measurement. Deceleration factor k of the electromagnetic wave also called refractive index is determined during measurement. This factor is calculated as a ratio of wave velocity in air (speed of light) to the speed of electromagnetic wave distribution in the controlled material. For ordinary materials (with low conductivity) this factor is equal to the square root of permittivity and ranges between 1 and 10. For high-conductivity materials deceleration factor rises sharply and can reach values as high as hundreds of units. 

Sensors of analyzers FIZEPR-SW100.27.6 and FIZEPR-SW100.27.14     FIZEPR-SW100 concentration meters can be used for in-line concentration control of sulfuric acid and other acids as well as alkali solutions and for measuring salt content in salt slurry. 

     It is possible to use these analyzers to control the water content in ion-exchange resins. For example, in the technological processes of recovery of spent ion-exchange resins to control the removal of excess water.   Another new application is gelatin moisture control in digesters.

    It should be noted that due to the high electrical conductivity of ion-exchange resins (as well as anthracite, gelatin, etc.), the use of conventional moisture meters on such materials is impossible.

            The test of the new measurement principle was performed on an ion-exchange resin of the brand Dowex HCR-S/S. The measurements were performed with two types of moisture meters: FIZEPR-SW100.30.26 and FIZEPR-SW100.11.6.       

Ion-exchange resin, sensor FIZEPR-SW100.30.26 Ion-exchange resin, sensor FIZEPR-SW100.11.6




  Below is a graph of the calibration dependence of the ion-exchange resin moisture meter. Devices provide reliable measurements of moisture content and can be used both in production and in technological processes using ion-exchange resins, as well as in the process of resin regeneration.

 The developed measurement principle is protected by patents.

A new patent for an invention

May 31, 2018

Together with our colleagues from PCE Deutschland GmbH, the patent of the European Patent Office for invention was obtained:

Moisture meter for bulk solids. European patent specification EP2921848 B1


December 7, 2017

We have manufactured the first batch of FIZEPR-SW100.10.16 moisture meters designed to measure moisture content in coal (anthracite), iron ore concentrate and NaCl salt.

These meters can also be used to control other high-conductivity bulk materials e.g. as potash, soda, aluminum hydroxide, ore, potassium salts, etc. FIZEPR-SW100.10.16 is also applicable when measuring moisture content in iron-ore concentrate and other magnetic materials.

The FIZEPR-SW100.10.16 coal moisture sensor is similar to the widely used FIZEPR-SW100.10.6 bulk material sensor in its design and installation in hoppers and on belt conveyors.

FIZEPR-SW100.10.16 moisture meter (explosion-proof version)

As opposite to the FIZEPR-SW100.10.6 version used on conductive materials with a probe-covering dielectric case (tube) only, the new moisture meter ensures measurements at virtually any conductivity of a material measured, and without any dielectric layer between the probe and the material. The solution designed improves significantly sensor reliability when operated on abrasive and lump materials.




The FIZEPR-SW100.10.16 sensor is made entirely of AISI 321 abrasion-resistant steel. On request, the sensor can be made of AISI 420 spring stainless steel hardened to 58… 60 HRC featuring exceptional strength and abrasion resistance.

In its other parameters the FIZEPR-SW100.10.16 coal moisture meter is equivalent to the well-known FIZEPR-SW100.10.6 version and similarly uses the dielectric measurement method.

The measured volume of a material to be controlled is 10…20 liters. Such a high volume of a simultaneously measured material eliminates any effect of inhomogeneous moisture distribution in the material and loose material-to-sensor contact while enabling measurements of materials with a size grade up to 30…40 mm.


FIZEPR-SW100.10.16 moisture meter and control cabinet


The moisture meter is available in explosion-proof version to control moisture content in coal and other explosive materials.

The new moisture meter is available in the 10.162 version (see figure enclosed) for measurements at temperatures up to 200ºС.

FIZEPR-SW100.10.162 sensor for high temperatures






The FIZEPR-SW100.10.16 moisture meter was originally designed to measure moisture content in sodium chloride (NaCl) in a hopper or conveyor belt flow. The moisture measurement range is 0 to 100%.

 The FIZEPR-SW100.10.16 moisture meter was designed in parallel with FIZEPR-SW100.27.х moisture meters similar to it in their operating principle intended to control the composition of sodium chloride slurry and other high-conductivity liquid materials in pipelines.

FIZEPR-SW100.27.x sensor


FIZEPR-SW100.27.х sensors are the result of FIZEPR-SW100.20.х series development and similarly made as a pipe with flanges. Working pressures (PN) are up to 160 bar, nominal bores (DN) are 50 to 100 mm. FIZEPR-SW100.27.х moisture meters are applicable in slurry control at cement production, measurements of coal-water slurry (CWS) fuel composition and salt slurry composition control (solid-to-liquid ratio measurement in a slurry flow).



Concentrate, W=10%FIZEPR-SW100.10.16 moisture meters were tested on iron-ore concentrate at Karelsky Concentrate, W=13%Okatysh and Evraztekhnika plants. The instrument ensures iron-ore concentrate moisture measurement in the range from 0 to 15%, i.e. from the dry material to the liquid slurry where concentrate is under the water layer as shown in the photo enclosed.

Concentrate, W=15,7%

Measuring Dryness Fraction of Steam. Control of Catalyst Activity in Reactors

May 1, 2016

The FIZEPR-SW100 dielectric moisture meter is modified for process media control at extreme temperatures. 


  • measuring of steam-water mixture composition (steam dryness fraction and moisture) in turbines and boilers at temperatures up to 374 ºC and pressures up to 220 bar and over;
  • control of media phase state and composition in high-temperature chemical reactors;
  • measuring parameters of powder and granular catalysts, control of their activity, coke formation monitoring;
  • measuring the cryogenic liquid level in Dewar vessels.


An engineering solution implemented in the new design enables measurements of media featuring extreme temperatures and pressures without any changes in accuracy. Refer to Patent No.  RU2576552 for description of the new analyzer design and measurement method:

Summary of the invention: the microwave signal receiver and transmitter are made as individual units connected by a uniform transmission line, e.g. by a cable. A primary transducer – probe – is connected to the middle section of the cable. It bypasses signal transmission by the cable when the transducer resonates.

This enables resonance frequency monitoring at a distance from the measurement area with extreme conditions. The working range of sensor temperatures is now determined by allowable ceramics and probe metal temperatures only. The introduced update has virtually no any impact on the permittivity measurement accuracy εr. The accuracy of measurement is up to 4 significant digits.

This solution makes it possible to not only measure material compositions remotely, but also monitor liquid media levels at a distance, e.g. coolant level at nuclear power plants or liquid level in vessels under pressures of several hundred atmospheres. The patent on the moisture meter for extreme conditions is available at:

The photos show a steam dryness fraction meter made based on the referenced patents. The steam dryness fraction meter is used in the steam-generating plant operated at the high-viscosity oil field. Working pressure is 22bar, working temperature is about 220ºС, and dryness fraction of steam is about  90%.

 Steam-water mixture in the pipe was quite stable as seen from the given spectrum. The record was made during 10 minutes and spectra recorded at 1-minute intervals were nearly coincident.


Refer to an example below displaying the FIZEPR-SW100 analyzer application in catalyst activity control with the results of measuring four samples of KDM-M chromia-alumina powder catalyst used in synthetic rubber production. The samples were taken from the existing unit for dehydrogenation of isobutane to isobutylene. Only reference numbers of the samples were marked on the sample labels before testing.

Measuring involves scanning a spectrum – frequency response of the sensor placed inside the material to be analyzed. The curves below show the measured spectra of Samples No. 1-4:

The FIZEPR-SW100 analyzer uses the spectra to identify dielectric parameters. The table below shows the results of measuring the catalyst dielectric parameters:

It appears that as the coke contaminates the catalyst, both its permittivity and dielectric loss tangent increase respectively.

Permittivity is increased by a factor of two (i.e. by 100 %); it is a dramatic change considering that the analyzer sensitivity is not worse than 0.06 % of the controlled parameter value.

Dielectric loss tangent of the samples changes by more than a factor of 50.

It should be noted that all types of catalysts based on aluminum and silicon oxides will produce the same results. The possibility to control the coke content is determined by the fact that the permittivity of coal and coke particles is significantly higher than the same of aluminum oxides and far higher than of silicon oxides, while the coal conductivity is greater than the conductivity of the materials specified by a number of times.

The FIZEPR-SW100 analyzer converts the dielectric parameters into the carbon ratio (or other value, e.g. the catalyst activity ratio) based on the calibration tables loaded in its memory. The calibration tables are compiled according to the results of catalyst sample measurements in a chemical laboratory.

Therefore, the FIZEPR-SW100 dielectric analyzer ensures a reliable monitoring of catalyst quality and activity directly in reactors at temperatures up to 800 ºС and higher.

Sawdust moisture control in the pellet production

April 3, 2014

Finally the comon problem has been solved - now it is possible to control the moisture of wood and saw waste materials. The water meter FIZEPR-SW100 is installed in the box above the conveyor belt. The material is poured from the top and output at the bottom from under the sensor by means of belt movement. It provides constant material renewal and stabilization of its density around the sensor. 

Level alarm for silos with cement

March 12, 2014

The range of bulk materials level alarms was completed with a new modification: SIUR-03В2.4.

This version as well as the SIUR-03В2.3 is designed for use under the gauge pressure in cement silos, but differs by the cable connection: sealed lead-ins are used instead of bolt connectors.

Desined and supported by Formatix Labs

Desined and supported by Formatix Labs

Website is translated by Lingvo-Prof translation agency

Website is translated by Lingvo-Prof translation agency