Problems and solutions of precession vortex flowmeter

Today, I will talk about the problems that will occur during the installation and use of the precession vortex flowmeter and how to deal with the solutions. The editor has compiled an overview for everyone. It seems to see if you have ever appeared? In order to solve problems later.

1. The current problems of the precession vortex flowmeter

    1. Setting of cut-off frequency: The user determines the starting flow of the instrument according to the production changes at the measurement site. If the cut-off frequency is set too high, the starting flow of the instrument will increase accordingly. It may cause the leakage of the flow to occur. If the cut-off frequency is set too low, the sensitivity of the meter will increase accordingly, and some weak external vibrations or stray signals may cause the meter to start to operate without the measured medium passing, so the phenomenon of multimeter flow is inevitable.

    2. Sensitive to interference signals such as noise or vibration: If there is a strong magnetic field near the measuring instrument or there is obvious noise disturbance upstream of the measuring end of the instrument, the operation of the instrument will be affected to a certain extent.

    3. The wide voltage adaptability and stability problems of the two-wire system output: Reversed power supply, overvoltage, and surge are common problems of the power supply and should be effectively overcome. And stability is the first issue that should be considered in the instrument design, because the actual industrial scene is mostly in harsh environments, and the reliability and stability requirements are very high.

    Two, the solution

    The cut-off frequency setting problem can be solved by the reasonable setting of the turndown ratio, and the noise interference problem can be solved in the following two ways:

(1) The installation position of the instrument should be selected as far as possible without pipeline vibration or small vibration, and the vibration acceleration should not be greater than 2g. If the vibration is large, vibration reduction measures should be taken;

(2) There must be enough straight pipes upstream and downstream of the sensor, and in view of the wide voltage adaptability and stability of the two-wire output, a 4-20mA current loop output circuit through serial input is designed. After digital-to-analog conversion, it is output in the form of 4-20mA current. It is very suitable for the design of smart transmitters. 4-20mA analog communication and digital signal communication under the HART protocol can be simultaneously realized between the main control device and the smart transmitter.

       Features of precession vortex flowmeter:

    (1) With frequency compensation characteristics (typical value): ± input offset voltage is 1 mV;

    (2) Input voltage range (typical value): When a wide input offset current is ±20 nA, no blocking will occur;

    (3) With 80 nA input bias current bias adjustment (typical value);

    (4) It has a built-in output short-circuit protection circuit;

    (5) Reverse connection of voltage can cause damage;

    (6) The input voltage range added to the input terminal cannot exceed the rated value, even in a short state;

(7) The normal operation input voltage range of the operational amplifier: +2V～+5±0.5V (typical value).

The above information and materials hope that the editor can help everyone here. Welcome to consult customer service online at any time to answer all your questions! What else you want to know, please tell me online, call 400-0117-885.