The main problems between ultrasonic and mechanical type: 1. Service life: Mechanical type is affected by water quality and will cause blockage, generally no more than 2 heating seasons; ultrasonic type is also affected by water quality, if there are no large particles in the pipeline And the flow rate is not large, the service life will be longer, and there may be a power outage. 2. Test results show that the current error stability of ultrasonic is not as good as mechanical, because the formal research and development of ultrasonic has only been 3 or 4 years. 3. Of course it’s the cost. Ultrasonic ones are more expensive than mechanical ones.