NYRD703 1.8GHz Guided Wave Radar Level Meter Level Transmitter
Measurement Of Low Dielectric Constant Media
NYRD703 1.8GHz Guided Wave Radar Level Meter
The guided wave radar level meter is a level meter based on the
principle of time domain reflection (TDR). The electromagnetic
pulse of the radar level gauge propagates along the steel cable or
probe at the speed of light. Part of the pulse of the level meter
is reflected to form an echo and return to the pulse transmitter
along the same path. The distance between the transmitter and the
surface of the measured medium is proportional to the propagation
time of the pulse during that period, and the liquid level height
is calculated.
Radar Level Meter Technical Parameter
| Parameters | Frequency: 100MHZ-1.8GHZ Measuring range:-cable :0-30m; rod, coaxial :0-6m Repeatability: ± 3mm Resolution: 1mm Sampling: echo 55 samples / s Response speed: 0.2S (depending on the actual usage) Output current signal :4-20mA Accuracy: <0.1% |
| Communication Interface | HART communication protocol |
| Process connection | G1-1/2 Flange DN50, DN80, DN100, DN150 |
| Process pressure | -1 ~ 40bar |
| Power | Power: 24VDC (± 10%), ripple voltage: 1Vpp Power consumption: max 22.5mA |
| Environmental conditions | temperature -40 ℃ ~ +80 ℃ |
| Housing protection grade | IP68 |
| Explosion levels | EXiaIICT6 |
| Instrumentation power supply and signal output wire connection | Sharing a two-core shielded cable Cable entry: 2 M20 × 1.5 (the cables diameter of 5 - 9mm) |
※ Note: Products can be customized according to the specific requirements of users!
Radar Level Meter Operating Principle
Guided Wave Radar is the kind of measuring instrument that is based
on the principle of time travel. The radar wave travels at the
speed of light, and its running time can be converted into a level
signal by the electronic components. The probe emits high-frequency
pulses which spread along the cable, and the pulses are reflected
back when they encounter the material surface and received by the
receiver inside the meter. The distance signal is then converted to
the level signal.
Radar Level Meter Installation requirements
Measurement Range
The blind area refers to the minimum distance between the highest
level of the material surface and the measurement reference point.
The bottom blind area refers to the distance near the cable bottom
that cannot be precisely measured.
The effective distance is the one between the top blind area and
the bottom blind area.
Note: Only when the material level is at between the top and bottom
blind areas can a reliable measurement of the material level be
guaranteed.
Installation Guide
The following installation guide is suitable for that of cable and
rod probes for measurement of solid particles and liquid. The
coaxial tubular probe is applied only to the liquid object.
Installation position:
Try to stay away from the outlet and inlet.
The meter should not touch the tank internal wall for metal tanks
and plastic tanks. If it is a metal tank, the material level meter
should not be installed at the center of the tank.
It is proposed to install at 1/4 of the silo diameter.
Probes of cable or rod types should keep a distance away from the
tank wall not less than 30cm.
The probe bottom should be about 30mm to the tank bottom.
The probe should keep a distance not less than 200mm from the
obstacles within the tank.
The sensor can be installed at the center of the tank top, if the
bottom of the container is a cone, so the measurement can be taken
to the tank bottom.
The picture on the right shows the rod-type radar installation
diagram, mainly used for liquid level measurement.
The down-pulling force applied to the cable
When charging and discharging, the material will generate
down-pulling force to the cable, which is determined by the
following factors:
- cable length
- material density
- tank diameter
- cable diameter
Installation guide for liquid measurement
The installation guide below applies to rod- and cable-type probes.
The tubular probe measurement is not related with the installation
method.
Installation position
- Distance to the tank wall is suggested as the 1/6 ~ 1/4 of tank
diameter (300mm at least, 400mm at least for concrete tank)
- Do not install at the metal tank center
- Do not install at the outlet
- Remember the probe bottom should keep a distance greater than 30mm
when select the probe length.
- Pay attention to the medium temperature.
Obstacles within tank
- Probe should keep a distance not less than 200mm away from the
obstacles.
Interference removal
- Interference suppression: The software could suppress the
interference echo, so as to achieve the ideal effect of
measurement.
- Bypass, wave guide pipes or tubes could be used to suppress the
interference when the viscosity is not greater than 500cst.
