In order to implement the Environmental Protection Law of the People's Republic of China and the Water Pollution Prevention and Control Law of the People's Republic of China, protect the ecological environment, and safeguard people
On December 24, 2019, the Ministry of Health and Ecology issued the "Technical Specifications for Installation of Online Monitoring Systems for Water Pollution Sources (CODCr, NH3-N, etc.)" and the "Technical Specifications for Acceptance of Online Monitoring Systems for Water Pollution Sources (CODCr, NH3-N, etc.)". In the "Installation Technical Specification", it is proposed that a flow monitoring unit is required in the composition of the online monitoring system. For the discharge units that need to measure flow, standardized measuring weirs (troughs) should be built for open channels, and the construction of weirs should be able to compare open channel flow meters. Triangular weirs, rectangular weirs, and Bacher troughs are recommended. In the "Acceptance Technical Specification", specific requirements are proposed for the acceptance method of water pollution source flow monitoring units, which are divided into liquid level error comparison and flow error comparison,
as follows:
(1) Comparison of liquid level error: Using a portable open channel flowmeter comparison device (liquid level measurement accuracy ≤ 0.1 mm) and an ultrasonic open channel flowmeter to measure the same level
Compare the liquid level values at the observation section of a water level, record the data pairs every 2 minutes for 6 consecutive times, and calculate the number of each group
Based on the correct error value Hi, select the larger Hi as the liquid level comparison error of the flowmeter.
(2) Flow Error Comparison: Use a portable open channel flow meter comparison device and an ultrasonic open channel flow meter to measure the instantaneous flow at the same water level observation section for comparison experiments. After the data is stable, start timing for 10 minutes. Read the cumulative flow F1 of the open channel flow comparison device and the cumulative flow F2 of the ultrasonic open channel flow meter during this period, and calculate the flow comparison error Δ F according to the formula.
According to the above requirements, it can be seen that portable open channel flow meters are required for on-site acceptance, and continuous statistical records should be kept during the acceptance process
The liquid level data and flow rate data need to be synchronously recorded within 12 minutes for both the online open channel flowmeter and the portable sewage flowmeter, with 6 liquid level data each. Additionally, the cumulative flow rate data for both the online open channel flowmeter and the portable sewage flowmeter needs to be synchronously recorded within 10 minutes. Moreover, since the sewage flow monitoring process is irreversible, any issues that arise during the recording process will require re comparison and acceptance, which poses difficulties in both time and space for on-site acceptance work.
To facilitate the rapid completion of the above acceptance tasks, the company utilizes multiple resources
Years of experience in developing environmental monitoring instruments, combined with the technical specifications for the installation of online monitoring systems for water pollution sources (CODCr, NH3-N, etc.), the acceptance technical specifications for online monitoring systems for water pollution sources (CODCr, NH3-N, etc.), and the technical requirements and testing methods for ultrasonic open channel sewage flow meters in HJ 15-2019, we have developed a portable open channel flow meter that meets the on-site acceptance requirements for open channel flow meters.
This portable open channel flow meter is mainly used for on-site technical parameter evaluation and acceptance of online open channel sewage flow meters, and can also be expanded
Applied to flow measurement of open channel sewage discharge by enterprises.


2、 Functional characteristics and technical parameters
2.1 Functional Features
(1) Suitable for four basic weir types: triangular weir, rectangular weir, equal width weir, and Bacher trough;
(2) High precision signal acquisition module, 24 bit acquisition accuracy, measurement data is true and effective;
(3) Large screen color LCD touch screen, touch operation, key data password protection;
(4) The curve displays the trend of flow rate and liquid level changes;
(5) A friendly human-computer interaction interface, combining graphics and text, allowing for instrument operation without the need for professional knowledge;
(6) The instrument is equipped with a micro printer, which can directly print measurement data on site;
(7) Can be connected to a computer to output measurement data to the computer, making it easy for users to perform statistical analysis on the data;
(8) Can store 10000 measurement history records;
(9) Equipped with a large capacity lithium battery, it can measure continuously for 72 hours on a single charge;
(10) The flowmeter is equipped with an intelligent power management system, which extends the battery life;
(11) Handheld box design, lightweight and convenient for users to carry, with a waterproof rating of IP65.
2.2 Technical indicators
Flow measurement range: 0~40m3/S;
Flow measurement frequency: 3 times/second;
Liquid level measurement error: ≤ 1mm;
Flow measurement error: ≤± 1%;
Signal output mode: USB;
Working environment humidity: ≤ 85%;
Working environment temperature: -10 ℃~+50 ℃;
Working power supply: AC 220V ± 15%;
Built in battery: DC 16V, lithium battery, battery powered continuous working time: 72 hours;
Dimensions: 400mm × 300mm × 110mm;
Whole machine weight: 2Kg.