Bicolor Level Gauge For Quartz Glass Tube

When the display of a quartz glass tube bicolour level gauge becomes unclear (such as a decrease in the contrast of red and green colors, blurring, or difficulty in distinguishing the dividing line), it is typically caused by the following reasons:

1. Scaling, Dirt Adhesion, or Impurity Sedimentation on the Inner Wall of the Quartz Glass Tube

• Cause: When measuring water, chemical media, or liquids containing suspended solids over a long period, minerals, crystals, oil stains, or impurities in the medium will adhere and deposit on the inner wall of the quartz glass tube.

• Effect: This directly obstructs or scatters internal light, destroying the original optical refraction effect and causing the colors of the vapor phase (green) and liquid phase (red) to become dim, turbid, or confused.

2. Failure or Angular Deviation of External Light Sources (or Built-in/Backlight Sources)

• Cause: Quartz tube bicolour level gauges usually rely on specific optical principles or backlighting (such as LED light sources, reflectors, or natural light incidence angles) to present distinct red and green colors. If the light source is damaged, the brightness is insufficient, the external ambient light is too strong/weak, or the incidence angle of the light source shifts:

• Effect: Light cannot properly penetrate the vapor and liquid phase zones, significantly weakening the bicolour contrast effect.

3. Partial Blockage of Vapor or Liquid Connection Pipes (Stagnant Medium or Minor Vapor Lock)

• Cause: The upper and lower valves are not fully open, or the pipes are blocked by impurities, leading to poor circulation of liquid or gas inside the level gauge.

• Effect: The internal medium remains stationary or marginally retained for a long time, potentially generating micro-bubbles or uneven concentrations locally, which affects the refractive index and results in an unclear display.

4. Changes in the Physical Properties of the Vapor-Liquid Two-Phase Medium Itself

• Cause: If the purity of the measured medium changes (e.g., a liquid that was originally clear and transparent becomes turbid, contains impurities, or darkens in color), its refractive index and light transmittance will change accordingly.

• Effect: A decrease in medium transparency directly weakens the optical bicolour display effect.

Troubleshooting and Handling Recommendations:

1. Flush and Drain: Periodically open the drain valve to flush and remove sediment at the bottom. If the inner wall is severely scaled, isolate the level gauge, disassemble it, and clean the quartz glass tube (taking care to avoid scratching the glass with hard tools during cleaning).

2. Check Lighting and Light Sources: Check whether the supporting light source (if equipped with LED backlighting or illumination lamps) is working properly, and adjust the viewing angle or ambient light.

3. Verify Valve Status: Confirm whether the upper and lower root valves are in the fully open state to ensure smooth medium circulation.