Moisture meter FIZEPR-SW100.17.X for concrete-mixing machines

Main feature of microwave moisture meters of the FIZEPR‑SW100.17 series is that the sensor has no protruding elements, which makes these moisture meters indispensable for measurements in mixers. Also, FIZEPR‑SW100.17 moisture meters are widely used for measuring materials on belt conveyors, scraper conveyors, and screw conveyors.

Videos demonstrating the use of moisture meters in industry can be viewed here: YouTube. The general catalogue of moisture meters for bulk and paste‑like materials, including moisture meters for concrete mixers, is available here: Catalogue

Moisture sensors for concrete mixers are manufactured in two main versions, differing in the design of the measuring head.

In sensors of the first version (modifications FIZEPR‑SW100.17.1, -17.2, -17.8, -17.85), the measuring head is made of cemented carbide, which is resistant to abrasive wear and also corrosion‑resistant. An undeniable advantage of this version is its resistance to mechanical impacts, which can be difficult to avoid during mechanical cleaning of mixers from hardened concrete. The measuring head of such sensors is replaceable and can be easily replaced when worn.

Sensor of FIZEPR-SW100.17.8 moisture meter in assembly with an electronic module   FIZEPR-SW100.17.85 moisture meter in assembly with an electronic module

Among this group, special mention should be made of moisture meters of modification FIZEPR‑SW100.17.85, which are designed for use in twin‑shaft mixers. The surface of the measuring head of these sensors is rounded with a radius that matches the radius of the mixer wear plate. (specified by the customer when ordering the moisture meter).

The use of cemented carbide ensures operation of sensors of modification 17.8x for at least 1 year under average mixer load, but in many cases the need to replace the head due to wear occurs much less frequently, for example, once every 4 years. Replacement of the replaceable head is carried out on site, quickly and without problems. Prices for replacement heads are low and are given in the Catalogue.

In sensors of the second version (modifications FIZEPR‑SW100.17.12 and 17.15), the measuring head is protected by a wear‑resistant ceramic disc. The discs are made either of silicon nitride.

FIZEPR-SW100.17.12 with mounting fittings  Microwave moisture meters FIZEPR-SW100.17.12 series with ceramic disk made of silicon nitride 

Ceramics, unlike hardened steel, are less susceptible to abrasive wear. Ceramic discs can be easily replaced if broken; detailed instructions for replacing the ceramic disc are given in the Operation Manual.

Measurement Data Processing & Display

Moisture meters FIZEPR‑SW100.17.x contain a microprocessor that performs mathematical processing of sensor signals. Modern digital filtering algorithms increase measurement reliability and eliminate interference signals caused by the passage of mixer blades near the sensor surface. This is clearly visible in the graph of a concrete production cycle below.

Recording at the recorder of the cycle of preparation of concrete

Measurements are performed with a period of 0.2 seconds. To transmit measurement results, the moisture meter is equipped with two output communication channels: digital (RS‑485 MODBUS RTU) and analogue (4‑20 mA). This solution allows the moisture meters to be integrated into automatic control systems for concrete mixing plants.

For process monitoring, it is recommended to display the information on a graphic recorder or computer, allowing the operator to track the process in real time, which helps reduce the concrete mixing cycle and improve its quality.

Design and Modifications

All moisture meters of the FIZEPR‑SW100.17 series are equipped with identical electronic units, and the sensors contain virtually no electronics; the sensors functionally serve only for emitting and receiving the microwave signal.

This design, where the electronic components are housed in a separate electronic unit, ensures ease of maintenance and increases the reliability of the moisture meters.

In addition to the microwave emitter, the sensor housing of the FIZEPR‑SW100.17.x moisture meters contains thermistors that allow monitoring the temperature of the measured material. The temperature value of the material is taken into account when determining its moisture content.

The design of FIZEPR‑SW100 moisture meters, the measurement method, and the mathematical processing methods are protected by more than 20 patents, both domestic and foreign. Descriptions of the inventions can be found here: https://fizepr.ru/patenty

All sensors of the FIZEPR‑SW100.17 series are supplied with a mounting kit, which includes a clamp (two clamping half‑rings) and a base ring that is welded to the outside of the mixer wall. The mounting kit allows easy adjustment of the depth to which the sensor is inserted into the mixer (the sensor surface should be flush with the wear plate or protrude no more than 1 mm beyond it).

FIZEPR SW100.17.8 sensor in a mixer

Sensors of the FIZEPR‑SW100.17 series can be divided into three groups according to body diameter:

• sensors FIZEPR‑SW100.17.8, FIZEPR‑SW100.17.85 and FIZEPR‑SW100.17.12 – body diameter 108 mm;
• sensors FIZEPR‑SW100.17.1 and FIZEPR‑SW100.17.2 – body diameter 80 mm;
• sensors FIZEPR‑SW100.17.15 and FIZEPR‑SW100.17.16 – body diameter 75 mm.

FIZEPR SW100.17.8 (Ø108mm) and FIZEPR SW100.17.1 (Ø80mm) with mounting kit

Sensors of the FIZEPR‑SW100.17.15 version are sealed (designed for operation at an overpressure of at least 6 kgf/cm²), and the operating temperature of the sensors is at least 150°C. These sensors are used in digesters. A skirt with a diameter of 126 mm is welded to the sensor body, which allows sealing the sensor mounting on the digester. The measuring head of the sensor is covered with a wear‑resistant ceramic disc.

FIZEPR SW100.17.15 sensor with mounting kit for installation in a digester

Based on the FIZEPR‑SW100.17.15 sensor, a new modification of moisture meters has been prepared for production – the microwave moisture meter FIZEPR‑SW100.17.16. This moisture meter largely replicates the design of the FIZEPR‑SW100.17.15, but is intended for use in digesters and mixers.

The delivery set includes a sealing device that ensures tightness when installing the sensor in mixers and digesters.

Explosion proof FIZEPR SW100.17.8 moisture meter

The new sensor has no skirt, and the mounting kit includes retaining rings similar to those used in FIZEPR‑SW100.17.12 sensors. This modification also uses a replaceable ceramic disc. The FIZEPR‑SW100.17.16 moisture meter is designed to replace Western‑made moisture meters with a body diameter of 75 mm.