Question

Related to ultrasonic flow meter: (i) Give any two types of it (ii) Write any two specifications (iii) Write two advantages over Rotameter.

Answer 1

### (i) Two Types of Ultrasonic Flow Meters:

1. Transit-Time Ultrasonic Flow Meter: This type uses the difference in time taken for an ultrasonic signal to travel downstream and upstream. The time difference is used to calculate the flow rate.
   

1. Doppler Ultrasonic Flow Meter: This type works by measuring the frequency shift of ultrasonic waves reflected off particles or bubbles in the fluid. The frequency shift is proportional to the flow velocity.
   

(ii) Two Specifications of Ultrasonic Flow Meters:

1. Flow Measurement Range: Ultrasonic flow meters can measure flow over a wide range, typically from very low to very high flow rates, depending on the model.
   

1. Accuracy: Ultrasonic flow meters typically offer high accuracy, often within ±1-2% of the actual flow rate, depending on the type and installation conditions.
   

(iii) Two Advantages Over Rotameter:

1. No Moving Parts: Ultrasonic flow meters have no moving parts, which means they require less maintenance compared to Rotameters, which rely on a float and a tapered tube.
   

1. Non-intrusive: Ultrasonic flow meters can be clamped onto the outside of a pipe, making them non-invasive. This allows for easier installation and no disruption to the flow, unlike Rotameters, which need to be integrated into the flow path.