The sensor device serves for detecting the absence or presence of a liquid (1) at the outlet (10a) of a feed line (10) through which there can be fed a feed substance which, when exiting from the outlet, has a pressure (p) in the feed line which has a course over time with a first characteristic in the absence of the liquid and has a course over time with a second characteristic in the presence of the liquid. The sensor device includes a sensing instrument (20-23) for sensing the pressure fluctuations in the feed line (10) and evaluator (30) which is designed to assign the sensed pressure fluctuations to the first or second characteristic and to generate a corresponding signal which indicates whether the liquid (1) is absent or present at the feed line outlet (10a).

A chromatography system comprising a mixing circuit or a mixing chamber, a bubble trap, a concentration detector and one or more pumps, characterized in that the bubble trap has a permanent opening at its highest point is described herein. Furthermore, a chromatography system is described, characterized in that it contains two concentration detectors the first of which is located in the mixing circuit or the mixing chamber and the second is located downstream of the main pump.

A measurement system includes a vessel for containing a fluid and at least one solid material and a probe assembly for disposing partially into the fluid within the vessel. The probe assembly includes a hollow tube having an open lower longitudinal end and at least one pressure sensor within the hollow tube, the at least one pressure sensor configured to measure pressures of the fluid within the hollow tube at at least two different elevations. A method of measuring a mass of suspended solids within a fluid the method includes receiving pressure measurements representing two different elevations of the fluid within a hollow tube and substantially free of the suspended solids and based at least partially on the received pressure measurements, determining a mass of the suspended solids.

A chromatography system comprising a mixing circuit or a mixing chamber, a bubble trap, a concentration detector and one or more pumps, characterized in that the bubble trap has a permanent opening at its highest point is described herein. Furthermore, a chromatography system is described, characterized in that it contains two concentration detectors the first of which is located in the mixing circuit or the mixing chamber and the second is located downstream of the main pump.

A triple bubbler system includes a first fluid probe, a second fluid probe, a third fluid probe, a gas source operably coupled to the first fluid probe, the second fluid probe, and the third fluid probe and configured to meter gas through the first fluid probe, the second fluid probe, and the third fluid probe to form bubbles at tips of each of the first fluid probe, the second fluid probe, and the third fluid probe, and a cover member disposed over the tips of the first, second, and third fluid probes and configured to at least partially prevent bubbles formed and escaping the tips of the first, second, and third fluid probes from interfering with other bubbles formed at each other tips. The bubbler system includes a thermocouple having a plurality of junctions disposed along an axis parallel to longitudinal axes of the first, second, and third fluid probes.

A car wash additive measuring system and method use a bubbler which provides a flow of pressurized gas through each bulk container. A pressure of each individual flow of pressurized gas is measured by a pressure transducer to output a signal indicative of the level of additive stored in the container. Flow rates of the respective flow of pressurized gas may be adjusted to accommodate particular additives.

A triple bubbler system includes a first fluid probe, a second fluid probe, a third fluid probe, an gas source operably coupled to the first fluid probe, the second fluid probe, and the third fluid probe and configured to meter gas through the first fluid probe, the second fluid probe, and the third fluid probe to form bubbles at tips of each of the first fluid probe, the second fluid probe, and the third fluid probe, and a cover member disposed over the tips of the first, second, and third fluid probes and configured to at least partially prevent bubbles formed and escaping the tips of the first, second, and third fluid probes from interfering with other bubbles formed at each other tips. The bubbler system includes a thermocouple having a plurality of junctions disposed along an axis parallel to longitudinal axes of the first, second, and third fluid probes.

A pneumatic depth sensor system for remotely reporting on a depth of a body of fluid is provided. The system comprises a regulated source of compressed gas, a first pressure sensor upstream from a normally-closed electronic solenoid valve, a second pressure sensor downstream from the electronic solenoid valve and a bubbler outlet downstream from the second pressure sensor, the bubbler outlet for locating at a bottom of the body of fluid, the depth sensor system under control of a microprocessor, the microprocessor in electronic communication with the first and second pressure sensors and the normally-closed electronic solenoid valve, and configured to instruct the normally-closed electronic solenoid valve to be in a fully open position or a fully closed position and to rapidly change position in response to a pressure reading from the second pressure sensor.

A pneumatic depth sensor system for remotely reporting on a depth of a body of fluid is provided. The system comprises a regulated source of compressed gas, a first pressure sensor upstream from a normally-closed electronic solenoid valve, a second pressure sensor downstream from the electronic solenoid valve and a bubbler outlet downstream from the second pressure sensor, the bubbler outlet for locating at a bottom of the body of fluid, the depth sensor system under control of a microprocessor, the microprocessor in electronic communication with the first and second pressure sensors and the normally-closed electronic solenoid valve, and configured to instruct the normally-closed electronic solenoid valve to be in a fully open position or a fully closed position and to rapidly change position in response to a pressure reading from the second pressure sensor.

A multi-tank indirect liquid level measurement device and method for wastewater tanks in a recreational vehicle may be implemented using a sealable reservoir that holds pressurized air, a manual piston pump that supplies and/or pressurizes the air in the reservoir, a rotary valve that incorporates a selection disk with an axial passage that is rotationally coupled to a connection disk that has a plurality of pipes, each of which connect on their other end to the wastewater tanks to be gaged. A bourdon tube pressure gage displays the pressure difference between the sealable reservoir and atmospheric pressure, which is an indirect reading of the height of the wastewater in the tank being gaged.