Measuring glass level at the feeder channel

Graphic glass production at the feeder channel

Reliable glass level measurement and control at the beginning of the feeder channel is necessary for a streamlined and efficient glass production as well as consistent glass quality.
Online glass level measurements offer non-contacting, continuous glass level readings with an increase in accuracy, reliability, and a reduced feedback loop that allows for improved response time. With this, process upsets such as low or high batch bin level or glass pull runaway can be assessed in seconds rather than in hours. Such an online measurement can be performed with a radiometric based level measurement. The principle of this measurement is based on the attentuation of radiation when penetrating matter.


  • Non-contacting measurement
  • Not exposed to the harsh process conditions
  • Removement of only some of the refractory bricks is necessary
  • Simple and precise adjustment of the calibration position via slider


Customer benefits

  • Online level measurement
  • Good repeatability of the measurements
  • Resistant to dust and gas



Technical features

  • Measuring range:
    typically 0...5 mm to 0...30 mm
  • Accuracy:
    +/- 0.5 % of the measuring range
  • Achivable resolution 0.05 mm (0.002 in)



Reliable glass level measurement arrangement and control

Due to the absorption of gamma energy it is common with nuclear glass level measurements to remove some, but not all of the sidewall refractory bricks on either side of the width of the feeder channel furnace. Using the laws of physics and statistics, as well as sophisticated software, the success of any nuclear-based measurement is almost granted. However, correct and exact application information is imperative for the design of an accurate and reproducible measurement.

Alignment and calibration

Typically, calibration points are taken at the maximum and minimum glass level operating condition. Calibration points are taken with glass flow remaining steady at the designed furnace glass level. A precise method to raise and lower the source shield and detector in lockstep to each calibration point can be achieved using a detector/shield mount that incorporates precision adjustable linear slide rails.
Glass melt furnaces require high resolution and repeatable level control of the feeder channel to ensure stable charging, flow, and glass pull. Accurate alignment and calibration of any glass level measurement system is critical to the performance of the measurement.

Berthold's measurement solution

DuoSeries LB 470

Radiometric level measurement DuoSeries LB 470 in true 2-wire technology


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