Question

Which of the following method is used to measure liquid level with the help of Geiger-Muller counter?

• A. Variable area method
• B. Inductive method
• C. Gamma rays method
• D. Capacitive voltage divider method

Hint:

This is often called "Nucleonic Level Measurement." It is the most expensive level-sensing technology but is sometimes the only option for extreme industrial environments where internal sensors would melt or corrode.

Answer 1

The Correct Option is C

1. The Radioactive Source: This method utilizes a radioactive isotope (typically Cesium-137 or Cobalt-60) placed on one side of the tank. This source emits high-energy Gamma rays.

2. Role of the Geiger-Muller (GM) Counter: A GM counter is placed on the opposite side of the tank to detect the intensity of the radiation passing through.

• If the liquid level is low, the radiation passes through the air/gas space and reaches the detector with high intensity.

• If the liquid level rises and blocks the path, the dense liquid absorbs much of the radiation. The GM counter then records a significantly lower count.

3. Benefits: Because Gamma rays can penetrate thick steel walls, the entire measurement system is external. This means the liquid never touches the sensors, making it ideal for corrosive, toxic, or extremely hot materials.