Calibration of Bachelier cells
Thread Content
Our company discharges its wastewater to a water treatment facility located outside Zone 1. The flow meter used to measure the wastewater discharge volume at the outlet is an electromagnetic flow meter provided by that water treatment facility, and our company removes it for inspection on an annual basis. Recently, in order to monitor corporate emissions, the environmental protection agency required our company to install a Batcher tank, and to upload data on flow rates as well as related monitoring parameters such as ammonia nitrogen, pH, and COD to the agency. Since the standard-free flow meters used in Bacheler tanks require regular calibration, there are no calibration facilities available in our company’s location that can perform such calibrations. I consulted the relevant staff at the Quality and Technical Supervision Bureau, who advised me to contact the Metrology Institute; the institute said it was unable to conduct the tests. Since there was already an electromagnetic flowmeter in the tank on site and the flow readings from the two meters differed little, is it illegal not to inspect the tank? Do any of you have any good suggestions?
Based on the owner’s description, this flow meter is used for environmental protection purposes and is a measuring instrument subject to mandatory calibration. It must be sent to a metrology testing institution authorized by the technical supervision department and qualified to carry out such calibrations; even local metrology institutes are not capable of performing this task. In my opinion, it would be possible to reach an agreement with the local technical supervision department to find a flexible solution for the calibration or adjustment of the device.
The Bacher tank is a fixed device; once it is purchased and installed according to your flow rate requirements, is there anything that needs to be calibrated? The flow meter that should be installed on the Bessel tank needs to be calibrated, right?
The Bessel tank is indeed a fixed device, but what is installed on it is not a flow meter but a level gauge. The Bessel tank, together with the complete set of secondary level gauge instruments (including calculation and remote transmission units, communication software, and interface units), constitutes the Bessel flow meter ； It can also be understood as an open venturi device. Since this device is not a standard throttling device but is designed based on test data, it is required by standard specifications to undergo a full set of tests.
According to **environmental regulations, it is required to install ultrasonic flow meters in open channels (Bacheler tanks), but we have encountered situations where calibration is not possible; there’s nothing else to do but smile about it.