Level detection is one of the four parameters in chemical production. As a scale of the internal media capacity of the container, it requires remote transmission and local indication of two types of level meters, just like pressure gauges and bimetal thermometers. Level meters are also factors that must be taken into account during the manufacturing process.

Level detection is the most common liquid level, boundary detection, the site shows the instrument according to whether the container is sealed by the pressure vessel is divided into a variety of forms, which pressure vessel detection is the most commonly used is the principle of connected vessels.

The principle of the communicator is to connect the instrument on the external surface after opening two welding flanges on the vessel wall. The distance between the two ports is the height of the measured medium. The external instrument also has two open connections to the flange of the device. In essence, the detection container of the external instrument is equivalent to the capacity expansion of the device.

The most widely used is the glass level gauge, which can be subdivided into glass tubes and glass plates. The glass plates are mainly used in high temperature and high pressure media detection, but in actual use, due to the measured medium Adsorption causes impurities to be adsorbed on the inner wall of the glass plate, causing reading difficulties, so the most common is the glass tube level gauge.

The glass tube level gauge is designed to be a two-color and three-color liquid level meter for the convenience of reading observation. This set different ribbons on the back of the glass tube realizes different color rendering of the ribbon according to the difference of the refractive index of light on the surface of the medium. It is more convenient to observe at night.

The glass tube level gauge is equivalent to adding a transparent container outside the container, which truly shows the liquid level inside the container. If the temperature difference between the inside and outside of the container is not very large, the density of the medium does not change drastically, but the medium level of the glass tube is The boundary bit shows the real value as the medium in the container. However, it should be corrected in consideration of the safety of boilers and changes in high-pressure water density in high-temperature high-pressure boilers.

The on-site level detection instrument is responsible for the rare input process in the even factory, so in principle, the level instrument fails, the instrument personnel do not need to repair, but in the daily work, the craftman often lazy, rarely or even do not maintain the glass tube level meter. .

As a result, the interior of the glass tube is often caused by the media impurities paste to make it impossible to observe the liquid level, and some glass tube level gauges have communication valves that are necrotic. The sewage discharge pressure valve is blocked, causing the glass tube level gauge to be unable to cut out for maintenance and cleaning. Inspection cannot accurately know the fluid level.

If the remote level instrument fails or suspects inaccuracy, the craftsman does not go to the scene to confirm but directly to find the instrument for repair, the essence of which is to allow the instrument personnel to confirm whether the liquid level in the equipment is accurate, that is, the instrument personnel are not alone. The repair of the table also includes the confirmation of the site level.