A differential pressure density meter is a type of instrument that measures the density of a fluid based on the difference in pressure across a sensor. It operates on the principle that the density of a fluid can be determined by measuring the pressure difference between two points in the fluid. This type of density meter is commonly used in industries such as oil and gas, chemical, and food and beverage for applications such as quality control, process optimization, and custody transfer.
Maintenance of Differential Pressure Density meter #
- During the use of the density meter, attention should be paid to shockproof, waterproof and anti-corrosion, and the electrical plug should be tightened and sealed. If corrosive liquid or gas is sprayed on the density meter, protective measures should be installed on the density meter shell.
- For viscous or crystalline media, when the pipeline or tank is emptied, the pressure-sensitive diaphragm of the density meter needs to be flushed in time to prevent the medium from adhering to the diaphragm, resulting in inaccurate measurement in the next operation. For diaphragm flushing, flushing water can be pumped into the pipeline, or the upper and lower plugs of the density meter can be removed, and the flushing hole can be cleaned with a water pipe.
Differential Pressure Density meter location selection and installation features #
To control the flow rate, first consider the bypass installation, so that it is convenient to choose a density meter with a small diameter and save money. When the density meter can only be installed in the main pipeline, we will select the appropriate density meter pipe diameter after calculating the flow rate according to the actual flow rate, and reduce the flow rate to the optimum value. The fluid flowing through the density meter will undergo the process of expanding and shrinking the pipe. , which should avoid the phenomenon of eddy currents. There is a wide enough distance between the measuring chamber of the density meter and the diaphragm, and the horn-shaped fox-shaped welding is used. Or the measurement error caused by the accumulation of bubbles.
How to deal with the zero-point drift of Differential Pressure Density Meter? #
When the differential pressure regulator density meter differential pressure transmitter appears the phenomenon that the density measurement drift is calculated to be zero, it can be dealt with from the following aspects:
1. First, check whether there is a density measurement drift calculation in the pipeline, whether the instrument is powered normally, then check whether there is a reverse polarity of the power supply, and finally check the electronic circuit board, pressure-sensitive membrane head, transmitter power supply voltage, etc.
2. No response to reading
If the density measurement drift calculation does not respond, check whether the valve of the pressure pipe is normal, whether the jumper switch of the transmitter protection function is normal, whether the pressure pipe is blocked, check the zero point and range of the white feeder, and replace the sensing membrane head.
3. Density measurement drift Calculate drift reading deviation
When the differential pressure regulator density meter differential pressure transmitter has the phenomenon that the density measurement drift calculation reading is obviously high or low, first check whether there is leakage in the pressure taking pipe, and then check the valve on the pressure taking pipe. Make fine adjustments, and if there is still a problem, replace the sensor head with a new one.
4. Density measurement drift calculation variable reading is unstable
This problem can be solved by isolating the source of external interference, checking whether the pressure guiding pipe is leaking, whether there is any debris in the pipe, whether there is clothing or deformation when checking the isolation diaphragm, and checking the pressure-sensitive diaphragm head.
However, some zero point changes are allowed, such as the zero point output value change caused by the difference between the installation position of the differential pressure regulator density meter differential pressure transmitter and the adjustment position. When the meter is calibrated, the measuring diaphragm is perpendicular to the ground, but the field installation When the measuring diaphragm is parallel to the ground or inclined to the ground, the zero point change caused by the deviation of the measuring diaphragm from the center position due to the self-weight of the diaphragm is a normal phenomenon. The smaller the measuring range of the differential pressure regulator density meter differential pressure transmitter, the greater the change value. Just set the changed zero output value back to zero by the zero adjustment
The reason for the zero drift is that the parameters of the transistor are affected by temperature. The most effective measure to solve the zero drift is to use a differential circuit.
How is the zero drift of the differential pressure regulator density meter differential pressure transmitter formed: The operational amplifiers are all directly coupled. We know that the Q points of all levels of the direct coupled amplifier circuit affect each other. The amplification effect of the first stage will make a large change in the output stage.
