Verification Regulations for Ultrasonic Flowmeters

『Verification Regulations for Ultrasonic Flowmeters』Related information(clamp on meter|electromagnetic meter|venturi meterrotameter|orifice meter|ultrasonic flow meter|mass flow meter|coriolis mass flow meter|coriolis flow meter|magnetic flow meter|magmeter flow meter|magflow flow meter|mag meter flow meter|electromagnetic flow meter|vortex flow meter|turbine flow meter|thermal mass flow meter|thermal flow meter|rotameter flow meter)

1. What is the calibration regulation for liquid ultrasonic flow meters? The calibration regulation for liquid ultrasonic flow meters in China mainly includes three categories: national general current standards, old versions of national regulations, and local calibration specifications. Specifically, they are as follows:

1. National general current calibration regulation JJG 1030-2020 "Ultrasonic Flow Meter Calibration Regulation" is the current national calibration regulation in China, and the core requirements include:

1. The inner wall of the pipeline should be clean and free of scale, and the installation angle deviation of the sensor should be ≤ ± 1 °;

; 2. Dynamic calibration should be carried out in sections within the flow velocity range of 0.1m/s to 25m/s; The measurement error limit for liquid media is ± 1.0%.

2. The old version of the national calibration regulation JJG 1030-2007 "Ultrasonic Flow Meter" calibration regulation can still be used in some scenarios. This regulation specifies the parameters for different calibration methods.

1. The mass method is applicable to the liquid flow range (1-600) t/h, with an extended uncertainty U_del=0.06%.

; 2. For liquid flow meters with diameters ranging from DN25 to 2000, the applicable flow range when using the standard meter method is (1 to 10000) m ³/h, and the extended uncertain orange blocking degree U_del=0.66%; 3. The simplified ridge cluster standard table method is applicable for liquid flow rates ranging from 1 to 1800 m ³/h in the field difference scenario, with an extended uncertainty U_del=0.26%.

III. Local Calibration Specification JJF (Qiong) 004-2025 "Online Calibration Specification for Ultrasonic Liquid Fl

owmeters Using Standard Meter Method" was released by the Hainan Provincial Administration for Market Regulation and will be officially implemented on July 1, 2025. The scope of application is:

1. Online calibration of ultrasonic flow meters for measuring the volume flow rate of single-phase liquid media installed on circular closed pipelines in a full flow state;

; 2. The diameter of the calibrated equipment should be ≥ DN300; When other caliber ultrasonic liquid flow meters are used for non trade settlement purposes, this specification can be followed.

2. The relationship between the minimum flow rate and the range ratio of 1:400 for ultrasonic flow meters

The core conclusion of the relationship between the minimum flow rate and the range ratio of 1:400 for ultrasonic flow meters is that the range ratio of 1:400 means that the minimum measurable flow rate is 1/400 of the full-scale flow rate, which directly reflects the lower limit and sensitivity of the instruments measurement range.

2. Factors affecting minimum flow rate • Sensor sensitivity: High frequency ultrasonic probes (usually above 1MHz) can detect lower flow rate signals. Signal processing algorithm: using FFT or cross-correlation algorithm to enhance small signal recognition ability. Pipeline conditions: The length of the straight pipe section should be ≥ 10D (D is the pipe diameter) to ensure a stable flow field. three Tech

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