1 measurement principle
Guided wave radar material level meter is based on the time domain reflectometry (TDR) based radar material level meter, radar material level meter electromagnetic pulse at the speed of light along the wire or probe propagation, when encountered the measured dielectric surface, radar material level meter part pulse is reflected form echo and along the same path to return to the pulse transmitting device, transmitting device and the measured distance from the surface of the medium with the pulse propagation time in the meantime is proportional to, by calculating the height of the liquid level.
Guided wave radar material level meter
2 installation guide
The following installation guide is suitable for measuring solid particle and liquid objects by cable type and rod probe. The coaxial tube probe is only suitable for liquid objects.
Try to stay away from the mouth and feed.
The metal cans and plastic bottles, not in the whole range of the wall. If it is a metal pot, the meter is not installed in the middle of the tank.
Recommended installation at 1/4 diameter silo.
The minimum distance between the cable type probe and the rod probe is not less than 30 cm.
Bottom of the probe is about 30mm.
The probe from the tank obstacle minimum distance of not less than 200mm.
If the container at the bottom of the cone type, the sensor can be installed
The top of the tank, which can be measured at the bottom of the tank.
Reflection of the pulse signal along the cable transmission to instrument electronic circuits and microprocessor this signal processing to identify microwave pulse echo reflected by the material surface. The correct echo signal recognition by the intelligent software is completed, the distance from the material surface of the distance D and the pulse of the time travel T is proportional to:
D=C x T/2
Missile radar level gauge 
C is the speed of light
Because the distance of the empty tank is known, the L is E:
Through the input air tank height e = (zero), Canful height f (= full scale) and some applications of the parameters to set, application parameters will automatically make the instrument to measure the environment. Corresponding to the 4 - 20mA with output.
3 range of measurement
H---- measurement range
B---- top blind
The minimum distance between the E---- probe to the tank wall
The top area refers to the minimum distance between the highest level of material and measurement reference point.
The bottom area refers to the bottom near the cable can not be accurately measured by a distance.
The effective distance between the top and the bottom of the blind area is measured.
Only when the material is in the top of the blind area and the blind spot of the blind spot, can be used to ensure the reliable measurement of the material level in the tank.
4 guide wave radar measurement of the installation of liquid
The following installation guide is applicable to the guide wave radar level meter of the rod and cable type probe, which is independent of the measurement and installation method.
The distance from the L distance to the tank wall is suggested to 1/4 1/6 (at least 300mm, concrete can at least 400mm).
L don't fit in the metal pot
L don't put in the bottom of the feed.
L select the length of the probe, the bottom of the probe is about more than 30mm
L pay attention to the medium temperature
L installation of the probe distance barrier at least 200mm
L interference echo suppression: software can achieve the suppression of interference echo, so as to achieve the desired results
L bypass pipe and guide wave tube (only for liquid) for viscosity does not hit 500cst, can be used to bypass pipe, guided wave tube or tube to avoid interference.
Liquid standard installation
The viscosity of less than 500cst and not easy to produce adhesion medium, tube type probe is the best solution, its features are as follows:
L excellent reliability
L can be used for any medium, which is more than 1.4 of the dielectric constant.
The barriers and the short size of the L tank does not affect the measurement
L is higher than the lateral pressure which can be subjected to the rod probe.
L for high viscosity of the medium, the proposed use of rod probe
Installation of instrument in horizontal and vertical tank
L tube probe and rod type probe can be 6 meters to 6 meters for measuring distance of the tank, can choose 8mm cable type probe
Measurement of L installation and fixed mode with solid powder silo
L no limit to the distance from the tank wall, as long as the probe can be avoided.
L if the tank obstacles more or too close to the probe, please use the tube type probe
Corrosive medium measurement
L if the measurement of corrosive medium, can be used to measure the guide wave radar material level meter with a rod probe
5. The technical parameters of the guide wave radar
Reference number: working frequency: 100MHZ-1.8GHZ
Measurement range: cable type: 0-30m; rod type, coaxial type: 0-6m
Sampling 55 times /s
Response speed: >0.2S (depending on the specific use of the situation)
Output current signal: 4-20mA
Communication interface: HART protocol
Process connection: G1-1/2
DN50, DN80, DN100, DN150
Process pressure: -1-40bar
Source: 24VDC (10%), ripple voltage: 1Vpp
Power consumption: 22.5mA Max
Environmental conditions: temperature -40 ~ +80
Shell protection class: IP68
Explosion protection class: EXiaIICT6
Two wire connection: common instrument power supply and signal output to a two core shielded cable
Cable entry: 2 M20 * 1.5 (cable diameter 5--9mm)