Gas flow meter
is an instrument for measuring the flow of gas. It is installed in pipes for recording the gas flow. It can measure gas, nitrogen, acetylene, phosgene, hydrogen, natural gas, nitrogen, liquefied petroleum gas, hydrogen peroxide, flue gases, methane, butane, chlorine, fuel gas, marsh gas, carbon dioxide, oxygen, compressed air, argon, methylbenzene, benzene, dimethylbenzene, hydrogen sulfide, sulfur dioxide and ammonia gas.
Thermal gas mass flowmeter utilizes the principle of thermal diffusion, while thermal diffusion is a kind of technology with good performance and high reliability even in harsh conditions. Its typical sensing elements include thermal resistance (platinum RTD): one is speed transmitter, and the other is temperature transmitter that can compensate temperature changes automatically. When the two RTD are exposed in mediums, the speed transmitter is heated to a constant temperature which is above the temperature of environment, while the temperature transmitter is used for measuring the temperature of mediums. The mass of gas that flows through speed transmitter is calculated by the heat transfer quantity of the sensing elements. When the flow rate of gas increases, more heat of medium will be taken and the temperature of sensor will accordingly decrease. In order to keep the constancy of temperature, the working current of sensor must be increased, the part of which should be proportional to the flow rate of the medium.