Disdrometers
Thies Laser Precipitation Monitor and Eigenbrodt ODM
The state-of-the-art Laser Precipitation Monitor (LPM) measures the amount, intensity and type of precipitation (ie drizzle, rain, hail etc). It is a highly accurate sensor measuring particles as small as 0.16 mm in diameter and provides excellent value and performance. It is also available as a weather station to measure wind speed, wind direction, temperature and humidity.
Another very good instrument is the Eigenbrodt ODM which is a specialist instrument generally recommended for ship applications as it deals with the particular aspects of obtaining good, accurate measurements with a moving vessel and dealing with sea spray issues.
Please select the model required for more information:
If you wish to measure visibility as well you may be interested in the Biral HSS VPF-730 sensor which is designed to provide visibility measurements first and also provides present weather data as well but not to the accuracy of the Laser Precipitation Monitor.
OPTICAL DISDROMETER ODM 470
Specialist instrument to measure drop size distribution on ships and buoys
The ODM is a specialist instrument for use on ocean vessels and deals with the particular aspect of obtaining high quality and accurate measurements on a moving vessel. The ODM compensates and adjusts orientation to deal with sea spray issues and wind speeds which may easily exceed 45 mph.
Proper measurements are made in any condition due to the design which ensures that the sensor is always properly orientated regardless of wind speed and direction. The sensor can be used for radar calibration.
Features
-
designed for use on moving ships
-
optimised for use in high wind speeds
-
detects droplets from 0.5 mm
-
mains powered
-
seawater-proof housing
-
no wind or sea spray induced errors
-
drop size distribution output with resolution of 0.05 mm
Laser precipitation monitor (Disdrometer)
The new generation of high quality and reliable precipitation identification sensors
The state-of-the-art Laser Precipitation Monitor (LPM) measures the amount, intensity and type of precipitation with great accuracy. The LPM is capable of measuring particles down to 0.16 mm diameter and can provide a drop size distribution with 400 classes. The data output is available in SYNOP, METAR, NWS, and in 4678 and 4680 WMO code. The system calculates intensity, volume (as water equivalent) and the spectrum of precipitation (diameter and velocity), the reduction to visibility in precipitation (MOR) and the radar reflectivity (Z).
FEATURES:
-
measures precipitation amount, intensity, type
-
measures particles down to 0.16 mm diameter
-
maintenance-free
-
mains or battery power
-
best cost / performance ratio
-
for all year round use
-
ability to add additional weather sensors*
OUTPUTS:
-
total precipitation quantity
-
particles speed / diameter
-
intensity mm/h
-
precipitation class (SYNOP/METAR)
-
radar reflectivity (Z/R ration)
-
MOR (Meteorological Optical Range) in rain
*Optional Sensors
wind speed*
wind direction*
temperature*
relative humidity* |
|
|
|
|
For more information on these optional sensors please see the Products page.
The LPM uses reliable laser-optics to detect and discriminate different kinds of precipitation including:
-
drizzle (DZ)
-
freezing drizzle (FZDZ
-
rain (RA)
-
freezing rain (FZRA)
-
hail (GR)
-
snow (SN)
-
snow grains (SG)
-
ice needles (IC)
-
soft hail (GS)
-
ice grains (PL)
With an integrated temperature regulated heater the LPM is suitable for all year round use. The sensor automatically compensates fluctuations of temperature or soiling of the optics. For use in harsh environmental conditions, for example in the mountains, a special model with extended heating is available.
We distribute the Thies Laser Precipitation Monitor (LPM) in several countries for Adolf Thies GmbH & Co Kg (Thies Clima) based in Germany. The LPM has been on the market since mid 2003 and was introduced at the WMO CIMO meeting in Geneva.
The LPM is very cost effective and because of this it really does represent excellent value. Several national weather services are now deploying them in large numbers and several other agencies and individual customers have also bought the sensor for radar calibration or present weather detection network stations.
Top of page
Data Output
With the following configurable digital outputs the LPM can be used as a precipitation monitor or as a tipping bucket type precipitation sensor:
The function of the digital opto-coupler outputs is programmable for example:
Output 1 - could be configured for 0.1 mm or 0.01 resp or 0.005 mm precipitation per pulse corresponding to the cumulatively measured precipitation quantity.
Output 2 - could be configured as a precipitation event monitor or as an additional event output, solid precipitation (snow, snow-grains, soft hail, hail) in conjunction with output 1.
In addition the following optional sensors can be connected to the optional measuring channels:
-
temperature (Pt100, not available for models with extended heating)
-
relative humidity (0-1 V / 0-100% relative humidity)
-
wind speed (frequency 0-630 Hz)
-
wind direction (serial synchronous)
Software
The data can be viewed on a PC via an RS-485 to RS232 connector (not included) using any HyperTerminal emulation, alternatively you can use the optional LNM-view software for easy data acquisition, storage and analysis. With this progressive Client Server architecture it is possible for several users to access the data simultaneously (multi-user ability). The software supports several instruments in parallel, the maximum number being limited only by the PC hardware.
Available models
The sensor can be provided in mains (100-260 VAC) or battery voltages (12-24 VDC) and includes models which can be used to accept additional sensors for wind speed and direction, temperature and humidity as well as models that allow the sensor to act as a tipping bucket rain gauge with pulse output for intensity and a relay for start and stop of rainfall.
The most important decision you need to make when ordering an LPM is to decide whether you need an LPM that has the weather station capability OR you need the additional relay / monitoring / Tipping Bucket Rain Gauge capability. The units cannot be updated to allow a change to the other style later on.
Model |
Description |
5.4110.00 000 |
A disdrometer featuring two digital outputs in addition to the normal output of the drop size distribution information. Both outputs are independent of each other.
The two digital outputs that can be used to either act as relay contacts (rain / no rain) type of switching or to indicate accumulation (similar to a tipping bucket rain gauge pulse output) for connection to an appropriate device to log this....or to indicate a condition (full scale output voltage when condition exists such as a type of precipitation (snow for example) or if a fault exists (no laser output for example...)
Voltages available:
24 VAC /DC or 22..30 VDC
115 VAC
230 VAC
12-24 VDC |
5.4110.01.x00 |
As above but with extended heating (not for VDC model) |
5.4110.10.x00 |
A disdrometer with the ability to add additional weather sensors such as wind speed, wind direction, temperature, humidity sensor to the LPM. The data from the additional sensors is modulated and output as a single weather data string for ease of data collection to a data logger or PC (optional PC software can be used to display and archive the data).
This model can be useful if you wish to mainly record precipitation information but also wish to have the wind speed and direction and temp/RH info as well but do not wish to have a separate logger for this...or wish to understand the precipitation better from the additional weather parameters.
The drop size distribution is still supplied in its entirety but the additional weather info is also included.
Voltages available:
24 VAC /DC or 22..30 VDC
115 VAC
230 VAC
12-24 VDC |
5.4110.11.x00 |
As above but with extended heating (not for DC model) |
Top of page |
