What is the principle operation of moisture microwave measurement?

Microwave moisture measurement is based on the dielectric properties of the material we wish to measure, and the significant difference in these properties between the material and the water within it. A material inserted into an electromagnetic field causes a change in the field parameters according to its dielectric parameters. Thus a connection can be found between the material moisture level and the field parameters such as amplitude and phase and empirically calculate the moisture level.
The transmitter and receiver are used to create the electromagnetic field and measure its parameters. Parameters translation into a moisture result is performed in the system's software.

How can small antennas measure moisture in large packages?
The microwaves radiated from the Transmitter Unit antenna are spread out and pass through the bales, and the Receiver Unit antenna collects them. This ensures that the majority of the volume of the bale is scanned.

Is the microwave radiation which the system produces dangerous?
Microwave radiation is dangerous to humans only if it crosses a certain intensity and exposure time. International standardization organizations have defined the approved radiation level according to experiments and research. Radiating Systems and instruments are required to pass radiation safety tests.
MALCAM's systems have passed safety radiation tests by the Israeli Standard Institute according to ANSI/IEEE C95.1-1992 and ICNIRP Guidelines (1998) standards. These tests proved that the radiation level of MALCAM's systems is only 25% from the approved level when touching the transmitter, and drops to 10% of the approved level when standing 50 meter apart from the transmitter.

Is the system sensitive to the color of the scanned material?
A moisture measurement system which is based on microwave technology is not sensitive to the scanned material color at all. (As opposed to other moisture measurement systems based on IR technology).

Is the system sensitive to the scanned material temperature?
Microwaves are directly influenced by material temperature. The higher the material temperature is the higher moisture the system will measure. In order to cope with this influence – the system automatically compensates the deviation in temperature. The operator has to provide the system with the scanned material current temperature.

How does material density influence the moisture measurement?
Density is defined as the amount of material in a certain volume. Thus changing the amount of material in a given volume will change the amount of water in the same volume. In order to compensate the influence of density on the results, we can define different material types for each density in the system, or we can perform automatic compensation according to the package weight, a parameter which can be

Is the system capable of measuring moisture in different size/weight packages?
The system handles different sizes/weight packages in the following manner:
In cases where the size of the package is fixed and the weight varies, then if the various weights are known and fixed – each weight is defined as a different type of material in the system, with different calibration parameters. If the various weights are un-known and not fixed at all – the system has to receive the weight parameter, directly or indirectly from the scale.
In cases where the size of the package varies significantly, Malcam has different systems that are designed to measure different sized packages by fitting the measuring channel to the scanned package size.

Do ambient conditions such as temperature, moisture etc., influence the measurement results?
No. The measurement principle is based on comparing the measurement results with and without the material, thus ambient conditions are already compensated.

What is the measurement accuracy we can expect to receive?
The accuracy depends on the type of material. However in general we can expect accuracy of around 3% of the measured moisture. For example, for a moisture level of 15%, the accuracy will be 0.45%