The innovation relates to a device and a method for measuring a powder mass flow for powder cladding. Before the powder cladding, the powder mass flow is set by means of a powder mass determining device and a powder mass flow sensor is calibrated on the basis of the setting. Then a powder switch is used to begin the powder cladding without interrupting the delivery of the powder mass. During the powder cladding, the powder mass flow is monitored by means of the powder mass flow sensor.

A testing method for testing a liquid flowmeter, the method including introducing a test liquid and a sealant having a specific gravity smaller than that of the test liquid into a weighing tank until an outlet of a pipe is submerged in the test liquid; causing the test liquid to pass through the pipe; acquiring readings of a weighing scale configured to measure a weight of the weighing tank at multiple time points, and time information representing the time points; acquiring readings of the liquid flowmeter; calculating a standard flow rate of the test liquid based on the readings of the weighing scale at the multiple time points and the time information; and calculating an instrumental error between a measured flow rate based on the readings of the liquid flowmeter and the standard flow rate.

Provided is a grain yield monitoring apparatus and method with a function of measuring moisture content, comprising a processor, a grain storage apparatus, a metering apparatus, and a counterweight apparatus. A grain yield monitoring method comprises: when a balance arm is in a balanced state, obtaining calibrated grain mass based on mass of a clump weight, and obtaining grain volume in the metering apparatus based on trigger position of arrays of photoelectric sensors; and obtaining measured grain mass of grain flowing through a flow sensor within a mass calibration time period based on a grain flow signal, calibrating grain mass based on an error between the calibrated grain mass and the measured grain mass to obtain a total grain yield, and obtaining a moisture content of grain based on the grain volume. The calibration of grain yield and measurement of moisture content of the grain can be synchronized.

A calibration system and methods for flow metering technologies integrates a known primary reference standard (e.g., a gravimetric scale), configured to determine a mass of calibration fluid, in parallel with surrogate secondary masters (e.g., Coriolis effect flowmeters) connected via an adjustable flowpath having a closed loop mode, including a meter bank, a pump and a measuring section, and an open loop mode, including a reservoir, the meter bank, the pump, the measuring section and the primary reference standard, which enables calibration duality and redundant meter under test confirmation of calibration factors. The disclosed systems and methods enable life cycle assurance of the primary reference standard and the secondary masters' standard reliability and reproducibility over time and, as a redundant system, enable calibration of multiple flow metering technologies, such as, for example, volumetric, mass, density, viscosity and Reynolds number-reliant technologies, in one homogenous system.