What is Real Digital Electronic Water Flow Meter?
Water flow meters are very important devices and often used in daily life and manufacturing. As the standard that whether have moving parts,water flow meters can be divided to mechanical type and electronic type. Digital water flow meters have no standard or official definition. But as usual understanding, it should at least have two important parts:
1).Digital display screen. This is different from traditional mechanical type water flow meters. Traditional flow meters are usually equipped with dial indicating reading, which is not convenient to read.
2).No moving parts. In the past, mechanical water meters are sensing water flow by moving parts, e.g. paddle wheel, etc. This design brings many disadvantages, e.g. short life, poor stability in long term, narrow wide flow range, easily blocked by materials in water, etc. Later as electronic technology development, many electronic digital water flow meters are released. Comparing with mechanical type flow meters, they have many advantages: higher accuracy, no moving parts, no pressure loss, long-term stability, versatile signal output, wide flow velocity range, etc.
4 Main Types Real Digital Electronic Water Flow Meters
From the two rules above, main selling electronic water flow meters have ultrasonic, electromagnetic, vortex, mass, etc on market. Except these types listed, there are also other types for niche requirement,but they are not main items, so don't introduce them.
1.Ultrasonic Water Flow Meter
Ultrasonic water flow meters are developed on the principle of time of flight and have no moving parts. The electronic water flow meters have been one of the main selling items in the area.
Ultrasonic flow meters can support ultra-low power consumption, this feature makes it more reliable to provide battery powered measurement without external DC/AC power supply. This is very useful for many applications where external power is not easy to get.
Ultrasonic water flow meter has 3 kinds of installing ways: clamp on, insertion and inline. Clamp on digital water flow meter doesn't need to cut pipe and easy to use. Inline ultrasonic water meters can support 6-10 years of battery life.
2.Electromagnetic Water Flow Meter
Electromagnetic flow meters are designed on Faraday law of electromagnetic induction. It senses water flow by stainless steel electrode. Magnetic water flow meters are one of the main selling product for water flow test.
It mainly has two structures: insertion and inline type. The inline type mag-flow are main selling models which features high accuracy and long-term reliability. The typical accuracy of inline mag-flow is 0.5 and max accuracy can reach 0.3-0.2.
Magnetic electronic flow meter can also support battery powered measurement, but its power consumption is bigger than ultrasonic flow, especially when pipe size is bigger, its power consumption is much larger. Thus, in order to ensure battery working life, its max pipe size is often limited to DN300mm under battery power.
Comparing with battery powered ultrasonic water meter, magnetic water meter has a much higher price. Thus, it is recommended to select ultrasonic water meters.
3.Vortex Flow Meters-Not Recommendation for Water Flow
Vortex flow meter is made on the technology of Karman Vortex Street.It can be used for gas and liquid,thus water is no exceptional.
But vortex flow meter is not often used for water.
Firstly, comparing with ultrasonic and magnetic flow, its price doesn't have good advantage,even higher.
Secondly,vortex meter is not so stable like magnetic and ultrasonic flow meter.
Thirdly,the performance of Vortex flow meter is easily influenced by strong vibration.
Thus,though vortex flow meter has no moving parts,it is firstly considered for gas flow measurement.
4.Coriolis Mass Flow Meters-Not Recommendation for Water Flow
Coriolis mass flow meters mainly have 2 kinds: thermal mass flow meter and Coriolis mass flow meter. Thermal mass flow meter is developed on two methods: power consumption measurement method and PT temperature measurement method.Coriolis mass flow meter is developed on the basis of modulation effect of fluid mass flow on the oscillation of vibration pipe, that is the phenomenon of Coriolis force. Both of mass flow meters have no moving parts and belong to electronic flow meters.
Thermal mass flow meter is mainly used for gas flow measurement. Coriolis mass flow meter is often used for liquid,thus it can be used for water flow measurement. The mass flow meter has a very high accuracy,but mass flow meter is very expensive, it is not necessary for water flow except project has extreme requirement for accuracy. So for most of applications, mass flow meters are not the first consideration for water flow measurement.
Don't be Misled by False Electronic Flow Meter!
Many companies have made a misleading advertisement to announce their flow meters are electronic water flow meters, but in fact the truth is not so. They just add a display unit to their mechanical water meters and mechanical flow meters. This is not real electronic flow meter and their core flow sensing part still has moving parts.
Thus, when you want to purchase flow device for your project, you should firstly check whether it is real digital electronic flow meters. The judging rule is very simple and just check whether the sensing part is mechanical type with moving parts.
The warm tip is that the first consideration is to select electronic flow meter when you have a requirement. Because false electronic flow meter will improve its cost after some time using, and you won't get benefit from real advanced electronic flow meter.