According to AGA's requirements. Report No.9 and the manufacturing level of existing materials and equipment, this standard requires gas ultrasonic flowmeter with ambient temperature of -25 ~ 55℃.
First, install the environment.
1, ambient temperature
Cold and hot environment will not only shorten the service life of the instrument, but also damage the measurement performance of the instrument. Therefore, any measuring instrument will make its own specific provisions on the adaptability of the external environment temperature. According to AGA's requirements. Report No.9 and the manufacturing level of existing materials and equipment, this standard requires gas ultrasonic flowmeter with ambient temperature of -25 ~ 55℃.
In addition, in some special cases (such as large temperature difference between the measured medium and the external environment and low test flow), it is suggested to install rain-proof and sun-proof facilities or take necessary heat insulation measures for the instrument and its upstream and downstream measuring pipelines in order to prevent additional influence of the external environment temperature on the measurement results.
Step 2 shake
Although the ultrasonic flowmeter has undergone strict mechanical vibration test before leaving the factory, as a precision measuring instrument, its measuring performance and life may be seriously affected if it is used near the vibration source or in a vibrating environment for a long time. Therefore, the only way is to stay away from or eliminate the vibration.
3. Electrical noise
As a kind of high-precision measuring equipment based on microelectronics technology, ultrasonic flowmeter has certain ability to resist external electromagnetic and electronic interference, but its installation site is often complex and changeable. If there is no requirement for "electrical noise" in the use environment, it may be inadvertently placed in the electronic interference environment of electromagnetic occasions, such as transformers or fixed wireless communication places, and the measurement accuracy and working reliability of the instrument may be affected.
Second, the pipeline configuration
1. Pipeline configuration for bidirectional flow measurement:
The so-called "two-way flow measurement" refers to the flow measurement when the measured medium is transported forward and backward with the same set of flowmeter. In other words, the upstream of the tool when it loses money in this period is the downstream of the tool when it returns in the next period. At present, underground gas storage or gas storage, which is usually used as peak shaving means in large and medium-sized cities, needs this kind of metering instrument with two-way metering function. This is the uniqueness of ultrasonic flowmeter. Therefore, when the ultrasonic flowmeter is applied to two-way flow measurement, its downstream must be treated equally according to the requirements of the upstream, which is also an important prerequisite for realizing two-way equal precision measurement of the ultrasonic flowmeter.
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