The OMEGA LVR20 and LVR30 Series continuous liquid level sensors operate on a basic voltage divider network principle. As the float rises, a magnet in the float closes a series of reed switches in sequence which varies the tapped-off portion of the voltage divider resistor network. The LVR20 has the basic voltage divider output the regulated DC voltage input equals the maximum voltage output. The LVR20 has a nominal 1,200 resistance; thus, with a 10 Vdc supply, 8.3 mA of current are required. The OMEGA DPF52 or DP24-E panel meters can be used to power and display the resistance from the LVR20; when relays are required, the DP25E-A meter can be used. For maximum accuracy, the readout device for the LVR20 should be zero and span adjusted after wiring is completed to compensate for any effects due to the resistance of the lead wires. The LVR20 can also be made intrinsically safe when used with OMEGA's intrinsic safety barriers and when properly powered. The LVR30 Series is provided with a signal conditioner to provide a 4-20 mA output when powered by 10-30 Vdc. The LVR30 Series cannot be made intrinsically safe. All LVR30 units are supplied with a J-box with screw terminal connections. All LVR20 units are supplied without a J-box with 24 inches of bare wire coming out of the top of the unit with a 1 /2 " MNPT conduit connection. All LVR20 and LVR30 Series units can be wired for increasing output with either increasing or decreasing height of liquid; standard output is increasing output with increasing height. For other lengths, adaptor systems are available. They consist of two parts: the LVR-C coupling (2 x 2" FNPT) and an LVR-A pipe nipple (2 x 2" MNPT) of various lengths to change the insertion depth of the LVR20 or LVR30 sensor. When using the adaptors, a zero offset is introduced into the output signal which must be compensated for in the readout device (for example, the mA signal will not go down to 4 mA, nor will the voltage output go down to zero). Retaining clip pliers are required to remove the float when using the adaptor system.

The LVU800 Series general purpose 2-wire ultrasonic transmitter provides non-contact level measurement up to 10 m (32'), and is ideally suited for challenging ultrapure, corrosive or waste liquids. Pushbutton calibrated, the transmitter is broadly selected for atmospheric bulk storage, day tank and waste sump applications. Media examples include wastewater and sodium hydroxide.

The LVRD500 Series comprises low-cost radar sensors for continuous level measurement. This series, a logical extension to the ultrasonic sensor series, is designed for applications requiring non-contact liquid level measurement, in which ultrasonic level measurement is not acceptable.
The LVRD500 Series radar technology can be adjusted for variables such as materials to be measured, vessel configuration, and system interface. These sensors are ideal when vapor, dust, or a foaming surface prevents ultrasonic-wave measurements.
LVRD500 Series radar sensors can detect the level under a layer of light dust or airy foam, but if the dust particle size increases, or if the foam or dust gets thick, they will no longer detect the liquid level. Instead, the level of the dust or foam will be measured. Internal piping, deposits on the antenna, multiple reflections, or reflections from the wall can interfere with the proper operation of the radar sensor. Other sources of interference are rat-holing and bridging of solids, as well as angled process material surfaces that can reflect the radar beam away from the receiver.

OMEGA's PX437, PX438 and PX439 Series submersible water level transmitters are designed to meet the rigorous environments of applications including well monitoring, pump tests, lift stations, chemical tank level, ground water and surface water measurement and process control and many others. They provide repeatable, precision depth measurements under the most adverse conditions.These transducers utilize a silicon pressure cell fitted into a stainless steel housing with an integral welded 316 stainless steel barrier diaphragm. The supplied calibration sheet specifies input and output data which reflects the unit's static accuracy and thermal characteristics. Each transducer is shipped with a moisture trap that prevents moisture from entering the vent tube. Replacement moisture traps are available as accessory items.

The three-wire ultrasonic level transmitter is the compact solution for non-contact continuous level measurement in process vessels, storage tanks and open channels. The transmitter also features a built-in 10A relay which can be configured as an alarm on a single set point or latched on two different set points for automatic fill or empty operations. Industrial and municipal liquid examples include sodium hydroxide, wastewater, resin, wax, liquor and bleach. An ultrasonic sound wave is pulsed eight times per second from the base of the transducer. The sound wave reflects against the process medium below and returns to the transducer. The microprocessor based electronics measure the time of flight between the sound generation and receipt, and translates this figure into the distance between the transmitter and process medium below.

The LVU30 Series of RoHS Compliant low-cost ultrasonic sensors that produce detection ranges from as close as 100 mm (4") to greater than 4.5 m (15'). Incorporating state-of-the-art ultrasonic technology, the sensors provide precision non-contact distance measurement for factory automation or industrial process control. The LVU30 series of sensors stand out over all other systems because of their affordability, extraordinary ease of operation, genuinely user-friendly software, versatility in usercontrolled outputs, and the ability to be set up without using a target. They transmit narrow beam sound pulses at a user-selected rate (software triggered), the process returns echoes, and various outputs depending on the position of the target and programming parameters.

The LVU40 series ultrasonic transmitters are advanced ultrasonic level measurement sensors for liquids. These products continue to meet demanding applications.
The microprocessor-based circuits provide a temperaturecompensated signal for improved accuracy. All models have the ability to filter false echoes produced by peripheral obstructions.
Continuous level measurement can be provided in a range of 0.3 to 18.3 m (1.0 to 60') with several power and programmability options. Point level can also be obtained using a PLC (Industrial Programmable Controller) or one of OMEGA's CNI process controllers.