WATER LEVEL METER LB-810W

functions: water level meter wide scope of work temperatures measurement and registry signaling the alarm states output for cooperation with a meteorological station LB-741

DESCRIPTION

Level meter LB-810W is designed for constant water level (state) measurement in the reservoirs and rivers using the echo sounder rule (measurement of the echo ultrasound return time). Additionally if the measurement is made over a river (a channel, a cannel with a tube, a channel with an overfall etc.) and if the dependency characteristics of the water flow intensity compared to its level are known then the device can count the actual water flow. The microprocessor used in the device counts the obtained distance measurement result (damming up of water H) to the amount of flow (Q) basing on the set characteristics (Q=f(H)). During installation one can introduce to the device's nonvolatile memory (using cooperating with the flow meter programmer LB-811) characteristics that were known earlier (maximum 19 measurement points). It should be stressed that introducing the measurement characteristic table to the device's memory is not final and can be performed many times. After programming the flow meter LB-810W the programmer LB-811 is disconnected, what secures the flow meter from any accidental reprogramming it by the user

A different way in which the meter can be used is the measurement of snow layer thickness.

The level meter was equipped with 2 transmitters, that can be started when the earlier set levels of the measured water are exceeded. The signals from the transmitters can start i.e. the pumps or the alarm signals in dangerous situations.

The analog outputs (4..20 mA and 0...10V) transmit the chosen measurement results (water level or flow intensity) allowing on attaching an analog register or any other executive device of a proportional work.

Digital output S300 LAB-EL provides current information concerning water level measurement results and can be attached (without any additional indirect devices) to one of the inputs in a field meteorological station LB-741, which also allows on connecting many other meteorological sensors and simultaneous registry as well as radio transmission of all measurement data to base (i.e. crisis management center). Other devices produced by LAB-EL company also cooperate with the digital output, i.e. universal reading panel LB-724 (allowing on simultaneous reading of the measurement results in remote places), converter LB-486 (allowing on i.e. creating an internet meteorological station). The output through a converter LB-371 can be attached directly to a PC computer. In order to connect the meter LB-810W with the mentioned above devices a two wire cable needs to be used. The cable's length can reach up to 500 meters (using a telephone cable 2x0,5 mm).

The meter consists of two parts: a probe (in version A, B or C) - assembled on an extension arm above the water surface and a servo - assembled in a closed place or in an additional metal casing in case of installation in the open space. Both parts of the meter are connected by a four wire cable with a screen and its length amounts to 30 meters. Power supply is led to the servo (the probe is powered from the servo).

Meter functions

• showing water level,
• controlling the executive devices depending on set level (transmitters),
• showing the moment flow values (LED screen),
• showing cumulated flow (24 hours),
• storing 28 last 24 hours flows in a nonvolatile memory (or the maximum water levels),
• showing the emergency work conditions,
• possibility of work with the meteorological and hydrological station automatic systems,
• possibility of work with the automatic systems (current outputs, voltage outputs),
• possibility of programming by user many work parameters (programmer LB-811),
• possibility of work with any river, channel, overfall or tube shape,
• automatic compensation of the changes in the ultrasound waves propagation speed caused by the changes in the center parameter (temperature, pressure, impurities) using distance measurement from a reference bar.

TECHNICAL DATA

• Measurement converter: piezoelectric ultrasound probe produced by SIEMENS
• Probe type from the liquid mirror can stay in the distance (various probe types):
• probe type A: 0,4 .. 1,3 m,
• probe type B: 0,7 .. 3,0 m,
• probe type C: 1,0 .. 6,0 m.
• Distance measurement error:
• probe type A: +/- 0,5 mm,
• probe type B: +/- 1 mm,
• probe type C: +/- 2 mm.
• Scope of work temperatures:
• probe -25.. +60 °C,
• servo -40 .. +60 °C.
• Analog outputs:
• current loop 4 .. 20 mA,
• voltage output 0 .. 10 V.
• Transmitter outputs signaling exceeding set level: fuse rating 230V / 2A.
• Digital interface: S300, speed transmission 300 bods, 7 data bits, 1 stop bit.
• Flow registry: flow meter registers in a nonvolatile memory the values and registry dates of the 28 last values of
  cumulated flow or water level in the period of 24 hours.
• Power supply: 230V / 50 Hz / 30 VA
• Overall dimensions:
• probe: 80 x 80 x 150 mm,
• servo: (width x height x depth): 280 x 220 x 145 mm (plastic casing).
• Degree of casing protection:
• probe IP67,
• servo IP64.

The picture shows an example measurement station equipped with the meter LB-810W

Produced by: LAB-EL Laboratory Electronics 68b, Bodycha Str., 02-495 Warsaw tel: (022) 667 71 18, 0601 209656, fax: (022) 867 53 32 e mail: info@label.com.pl home page: http://www.label.com.pl internet meteorological station: http://www.meteo.waw.pl meteorological station on a mobile phone: wap.meteo.waw.pl Last updated: 09.05.2004