Switches Indicators & Gauges

What are Gas Bubbler Systems?

One type of basic gas bubbler system is a glass bulb containing a small amount of fluid, with the inlet to the bulb connected to a ground glass joint and the outlet vented to the air. They are used in laboratories to exclude air from a reaction, or to prevent air contaminating a system. In the first case, the gas bubbler is fitted on the condenser of the reaction set-up. In the latter, an oil bubbler is installed at the end of the inert gas manifold on a Schlenk line. The schlenk line is a chemistry apparatus used for manipulating air sensitive compounds. Gas bubblers act as a one-way valve, where gasa bubble through the fluid before being vented. In this way, if there is a lack of pressure some fluid is sucked intoa sump to equalise it rather than air.

In a purge gas pressure monitoring system, a piezometer tube runs from a pressure measuring instrument into a medium to be monitored. A piezometer is an instrument for measuring pressure, especially very high pressure, or for measuring the compressibility of materials under pressure. Purge gas is carried to the tube to escape as bubbles as the end of the tube are submnerged in the medium. The pressure of gas escaping from the tube relates to the pressure of the medium into which it is bubbled. This is then measured and the data is send to a data recorder.

WATERLOG® H-355 ‘Smart-Gas’ System

The Waterlog ‘Smart-Gas’ system is a reliable, light weight and low power unit suitable for use in the most remote locations. The automatic bubbler system can replace nitrogen tanks, oil sight feeds, flow regulators and leaky manifolds that are heavy and dangerous.

This systems is a complete single unit replacement that can be used at a depth of up to 115ft, uses no mercury with selectable flow rates, and controlled or automatic purge functions.

The Development of Tools

The basic definition of a tool is an object that creates more effective action of one thing upon another. Simple machines are based on what type of action this involves, whether a lever, wheel and axle, pulley, inclined plane, wedge or screw. These basic categories were defined by Renaissance scientists, and are the basis of complex machines. Although multiple species utilise tools, including monkeys, apes and sea otters, what is unique about humans is that we are the only species that uses tools to create other tools. There are called machine tools.

A machine tool is a powered mechanical device, usually used to fabricate metal components, thus removing the human element in the physical production of tools. After the Industrial Revolution and the development of the steam engine, machine tools were able to be powered by steam. Today most are powered by electricity, and can be operated manually or automatically. Examples of machine tools include the drill press, gear shaper, lathe, hobbing machine, shaper, planer, broaching machine and grinder.

Machine Tools and Mass Production

The invention of machine tools led to the development of mass production. David Hounshell states: “The new manufacturing technology spread first to the production of a new consumer durable, the sewing machine, and eventually it diffused into such areas as typewriters, bicycles, and eventually automobiles.” (1984, p4) It took off from the small arms industry such as Colt’s Patent Firearms Manufacturing Co. As manufacturers worked with the makers of machine tools, they overcame problems related to the cutting, planing, boring and shaping of metal parts.

This ” technological convergence” would lead to the Fordist system of manufacturing and labour division. This system, named after Henry Ford, was based on mass production to lower the price of the product, and simultaneously raising workers’ wages to feed massive consumption. The system emphasised synchronisation, precision and specialisation, and would lead to the economic dominance of the United States from the 1940s onwards.

Level Sensors

Level sensors are used to detect levels of substances that naturally flow to become level in whatever physical boundaries constrain it. This can include substances such as liquids, semi-liquids (e.g. slurries), or solids (e.g. granules or powders). Level sensors can detect continuous levels, measuring within a specified range to determine the specific amount of substance in a certain place. They can also measure at specific points, generally whether the substance is above or below the sensing point (excessively high or low).

Continuous measurement of liquids can use magnetostrictive level sensors, resistive chain level sensors, hydrostatic pressure level sensors and air bubbler level measurement systems. Sensors for point-level measurement of solids include vibrating sensors, rotating paddle sensors, mechanical sensors, microwave sensors, capacitance sensors, optical sensors and ultrasonic sensors. Sensors that can detect both point-level or continuous-level measurements of solids and liquids include capacitance sensors, optical interface level sensors, ultrasonic level sensors and microwave/radar sensors. The type of sensor used depends on the type of substance (i.e. liquid, semi-liquid, or solid), agitation or vibration, density, whether it must detect measurements in a vacuum or under pressure, the temperature, the type of container, the chemical composition of the substance, noise and so on.

Submersible level sensors

Hydrostatic submersible level sensors are used for measuring the level of corrosive liquids in deep tanks, such as the NivoPress NP that Semrad Pty Ltd offers. This level sensor consists of a probe and a breathing cable containting a capillary pipe (i.e. with a ver small diameter) and a stress resistant inlet. The probe is a stainless steel cartridge, suitable for clean or faintly chemically tainted liquids (whether in tanks or water reservoirs). Its main purpose is to monitor submerged pumps, as it is capable of fully functioning while immersed in water. Hydrostatic level sensors basically sense increasing pressure with depth (calibrated to the specific substance).