The “Critical Flow Venturi Sonic Nozzle Gas Flow Standard Device” is a standard for the unification and transfer of flow unit values, and is a standard measurement device for the value traceability, value transfer and detection of gas flow detection equipment. This set of devices uses the critical flow Venturi nozzle as a standard table and air as a test medium to perform metrological verification, calibration and inspection of various gas flow meters .

The absolute pressure transmitter and temperature transmitter configured in this device measure the airflow pressure and temperature before and after the nozzle and the flowmeter being tested, as well as the nozzle back pressure. The control system synchronously collects and processes various parameters in real-time during the calibration process. The lower computer judges and averages the data uploaded by the transmitter and stores it. During this period, the data distorted by the transmitter itself is eliminated. After receiving the average data from the lower computer, the upper computer stores it in the transmitter verification result database, and at the same time performs a secondary judgment and screening on the stored data to ensure that the data involved in the calculation is accurate and reliable, and the correction is truly realized.

In the computer system of the device, the operation of establishing or modifying the basic data of the system is set. In addition to the transmitter verification result database, a nozzle basic database is also built to store the parameters such as the serial number and outflow coefficient of each nozzle equipped with the device. If the nozzle verification data changes or a new nozzle is replaced, the user only needs to modify the basic data.

1. System features
It can weigh vehicles passing at low speed and automatically determine whether the vehicle weight or axle weight is overloaded;
It can detect the number of axles, axle groups, axle weight and vehicle weight of the vehicle;
It can form complete vehicle weighing information, including axle type, axle weight, axle group and total weight;
It can transmit weighing information to the computer through the data interface;
The core part of the system adopts mature and reliable equipment, all of which adopt modular design, easy to maintain and expand, ensuring the high reliability of the system.
The system software is mature, reliable, and the data is complete and effective, and it can be fully shared, effectively improving work efficiency and eliminating various management loopholes to the greatest extent.
2. System composition
The overload and overlimit system consists of ZDG eight-module dynamic axle weighing scale, control instrument, infrared vehicle separator, weighing platform wheel axle identifier, control cabinet, (optional equipment: license plate recognition system, LED large screen display system, voice prompt system, vehicle guidance system, industrial computer, ticket printer, UPS uninterruptible power supply, overload and overlimit detection system software, monitoring system) and other accessories and cables.

Its permeability level can reach IP68 and the precision is very accurate. It has multiple functions such as fixed value alarm, counting, and overload protection. It is easy to install and convenient to use. Both the platform and the indicator are waterproof. Both are made of stainless steel.

Its permeability level can reach IP68 and the precision is very accurate. It has multiple functions such as fixed value alarm, counting, and overload protection.

Applications

• Compression Measurement 
• High Moment/Off-Center Loading
• Hopper & Net Weighing
• Bio-Medical Weighing
• Check Weighing & Filling Machines
• Platform and Belt Conveyor Scales
• OEM and VAR Solutions

–Inoxydable materials,laser sealed,IP68

–Robust construction

–Complies with OIML R60 regulations up to 1000d

–Especially for use in refuse collectors and for wall mounting of tanks