Are the electromagnetic waves produced by radar sensors dangerous?
According to the latest scientific research, the electromagnetic waves from VEGA radar level sensors are harmless. The sensors operate with a peak power output of under 0.5 mW, whereas a mobile telephone operates with 1 to 2 W of transmitting power!

What is the difference between C-Band radar level sensors and K-Band radar level sensors?
C-Band radar level sensors operate in a waveband of 5-6 GHz. The implemented horn antennas have a diameter of 150 mm or more. K-Band radar level sensors operate in a waveband of 25-26GHz. Here, the implemented horn antennas have a diameter of 40 mm or more.

Does the sensor antenna have to project into the container or can it remain within the mounting socket?
The active surface of the antenna (antenna edge) should project into the container and not remain in the mounting socket. If however the mounting socket cannot be shortened, antenna extensions or K-Band sensors can be used.

What is the polarisation of a radar sensor?
The polarisation of radar level sensors defines the spatial orientation of the electrical and magnetic components of the emitted microwaves.
VEGA radar sensors are linearly polarised, thus the electrical vectors are linear in space.
The polarisation of a VEGA radar sensor represents the direction of the electrical vector and is indicated by a marking on the process fitting.

How does the polarization of the radar wave influence the measuring result?
The emitted microwave of a radar sensor consists of a magnetic and an electrical component. Both components (also called fields) are at an angle of 90° to each other. The reflective properties of the electrical and the magnetic field are different. As a result, the wanted signal can be reinforced, or interfering signals attenuated, by turning the antenna system of the radar sensor on its longitudinal axis.

What is the difference between the pulse radar method and the FMCW radar method?
A pulse radar sensor sends out a very short pulse which is reflected by the measured product and received back at the antenna. The time between emission and reception, which is proportional to the travelled distance and thus to the filling level in the vessel, is measured. An FMCW radar sensor sends out a continuous frequency-modulated signal. This signal is also reflected by the measured product and received back at the antenna. Because of the time the signal requires to travel the measuring distance, the sensor receives a different frequency than the one it sends out. The difference between these frequencies, which is also proportional to the travelled distance and thus to the level in the vessel, is measured.

What is the difference between contactless level measurement with radar and contactless level measurement with ultrasound?
Radar waves (electromagnetic waves) propagate without a supporting medium, i.e. they also travel in a vacuum! Therefore, the velocity of propagation is virtually unaffected by gases, no matter what their temperature or pressure. The measuring result is thus completely independent of these process factors! Ultrasonic waves need a medium to travel in, which is in most cases the surrounding air. The propagation velocity of the ultrasonic wave can vary greatly depending on the type of gas, as well as its temperature and pressure. The measuring result is thus directly dependent on these influencing factors!

Recommendations for ammonia applications
The best results with applications in ammonia were achieved with instruments with a ceramic/graphite seal, because this material is diffusion-proof. Sensors in which elastomer seals are used are not suitable for these applications: