For sonar measurement, the transformer oil conservator tank level is a relatively simple condition, mainly as follows.
1. The diameter of the transformer oil conservator tank is commonly not large, which means that the measuring range of the monitor is relatively small, so the transmitting circuit requires not much power.
2. Transformer oil is pure (no impurities, precipitation, etc.), with good acoustic performance, the signal in the propagation process attenuation is small, so the receiving circuit is without too much gain.
3. The oil level inside the conservator tank is relatively stationary, the oil-gas interface has good reflection performance on the transmitting wave, the echo amplitude is strong, and the time is stable, so the oil level measurement is very reliable.