Research on the standard device of multifunctional liquid level gauge with automatic valve control

The types of liquid level gauges are increasing day by day, and their performance is constantly improving. With the continuous expansion of the liquid level meter market, higher requirements have been put forward for the calibration efficiency of liquid level meters. In order to meet the calibration needs of different types of liquid level gauges, the team has developed a multifunctional liquid level gauge calibration device. The range of the device is (0-2000) mm (MPEV=0.35 mm), with a resolution of 0.01 mm. The device mainly consists of a camera, a stainless steel water tank, a tested liquid level gauge flange, a steel ruler, and a pressure standard. The upper computer is programmed using configuration software to achieve automation of liquid level gauge calibration. The device can collect (4-20) mA electrical signals, display liquid level readings, and output a range of (0-2500) mmH2O. After uncertainty evaluation, within the measurement range, the extended uncertainty of the liquid level indication of the liquid level gauge calibration device is 0.12 mm (k=2), and the extended uncertainty of the output electrical signal is 4.0 × 10-3 mA (k=2), which can meet the detection requirements of the contact type liquid level gauge.