+ Submit your article here

Types of Level Gauges

10/16/2013 8:15:10 AM | by Anonymous

Level Gauges

Level gauges are type of level measurement devices that are mainly employed in the industrial instrumentation field to detect the level of fluids or liquid which is contained by a storage tank or process vessel. These levels of sensing devices are considered very simple and fast to inspect the level gauges. They can also be detected by any type of vapor leakage.


Level gauges are is available in various types of different materials like plate glass, glass tube or reflex plate glass depending upon the use. They can be prepared from the glass tubes as they are employed for boiler applications. Some of the major types of level gauges may include magnetic level gauges, transparent level gauges, reflex level gauges and bi-color gauges.


There are many different types of level gauges exist in the industry; however they are depended upon the types of liquids such as oil, diesel and water by the level gauges. Some different types of gauges level are mentioned below.


Magnetic level gauge is used for toxic liquids or highly hazardous where the gauge glasses are susceptible to attack by the process medium. This type of gauges has a maximum working temperature and pressure ranges at 220 bars and 4000C respectively. The uses of these devices are mainly recommended for risky, combustible and corrosive fluids. They are also capable for inter-phase level detection.


Liquids can also be measured by gauges that involved in extremely high temperature and pressure. They can be installed in underground storage tanks too. However, this type of level sensors works upon two principles which are Archimedes and phenomena principles. Archimedes principle is sealed as any object that submerged in a fluid tends to experience the same buoyant force as the weight of the liquid is lighter. The other principle of phenomena is repulsion between the opposite similar poles of the permanent magnets respectively.


Reflex level gauge is employed for detection of level in a vessel. Its working pressure and temperature is range up to 400 bars and 4000C respectively. It is used for construction which includes stainless steel and carbon steel. Its operating principle is depended upon the dissimilarity in the index of reflection between vapors and fluids. The liquid column is contain within the liquid chamber behind the sight glass such that a transparent tube is clamped to the gauge body whereas the sight glass has a right angled that is facing the side of the vapor and liquid space. The presence of vapor and liquid area has external light waves coming towards the reflex gauge level that will undergo either reflection or absorption.


Transparent gauge level is a functional pressure and temperature range that is similar to reflex gauge levels. The constructional materials and features of transparent level gauge used are almost the same too. This level control gauge consists of two transparent glasses which are integrated with the liquid cavities of both sides. The level of liquid can be detected depending upon the dissimilarity in the transparent characteristics of the two glasses. In case of steam and water applications, an illuminator can be employed at the back end of the gauge to simplify the viewing of the liquid level by the observer. The light rays can be emitted by the illuminators that are directed in an upward direction towards the water column which the surface of the liquid gets illuminated. Light radiations will tend to fall upon the divided surface between steam and water then finally reflect back to the eye of the viewer.


Bi-color level gauges are the most appropriate for measurement of level in boilers since the glasses are used in the construction and they are carefully guarded against the wet steam which is generated by a boiler drum. The detection of level in bi-color gauges are depended upon on the index of reflection between the water and steam. They are both workable with temperatures at 120kg/cm2 and are well-suited for saturated steam applications.


They are transparent gauges with the liquid chamber in a wedge shape section and are usually fitted on a rear side with an illuminator. They are in red and green color filters that are positioned directly facing the light source in the illuminator hence the name is called bi-color gauge. In some cases, if the red color light radiations hit the water, they will get averted to one side and absorbed when they encounter the steam region but they tends to pass through without any constrictions. On the other hand, the reverse action will take place if the light radiation passes the green filters.

Are you sourcing for a product or service?

Do you need a quotation?