Abstract: The present disclosure relates to a device and a system for testing flatness. The device for testing flatness includes a base, a testing platform, and a ranging sensor. The testing platform is assembled on the base. The testing platform includes a supporting structure. The supporting structure is disposed on the side of the testing platform away from the base and is used to support a to-be-tested board. The structure matches the structure of the to-be-tested board. The ranging sensor is disposed on the side of the testing platform away from the base. After the to-be-tested board is placed on the testing platform, the ranging sensor is used to test distances between a number N of to-be-tested positions on the to-be-tested board and the ranging sensor, to obtain N pieces of distance information, and the N pieces of distance information are used to determine the flatness of the to-be-tested board, where N is an integer greater than 2.

Abstract: A water cooling structure of a reducer and a reducer assembly are disclosed. The water cooling structure comprises a chamber formed by a reducer housing and a cover plate, and the cover plate is fixedly connected to the chamber. The chamber is provided with a water inlet and a water outlet respectively. The chamber is also provided with one or several partition plates on two opposite side walls. The partition plates are arranged in an interdigitating manner and each of the partition plates is connected with only one side wall of the chamber, and there is a gap between the partition plates and the opposite other side wall of the chamber, so as to form an S-shaped water path. The water inlet and water outlet are respectively disposed at both ends of the water path. A plurality of baffles are further vertically provided on the partition plates and side walls of the chamber that are parallel to the partition plates, and the baffles are arranged in an interdigitating manner.

Abstract: A water cooling structure of a reducer and a reducer assembly are disclosed. The water cooling structure comprises a chamber formed by a reducer housing and a cover plate, and the cover plate is fixedly connected to the chamber. The chamber is provided with a water inlet and a water outlet respectively. The chamber is also provided with one or several partition plates on two opposite side walls. The partition plates are arranged in an interdigitating manner and each of the partition plates is connected with only one side wall of the chamber, and there is a gap between the partition plates and the opposite other side wall of the chamber, so as to form an S-shaped water path. The water inlet and water outlet are respectively disposed at both ends of the water path. A plurality of baffles are further vertically provided on the partition plates and side walls of the chamber that are parallel to the partition plates, and the baffles are arranged in an interdigitating manner.

Abstract: The present application discloses a metering system for calculating a real-time profit or loss of a gas station, including a metering module, a level gauge of the oil tank, and a communication management machine with a built-in data processing module; the metering module and the level gauge are respectively communicated with the communication management machine; the oil tank, an oil pipeline of the oil tank and an oil inlet of the fuel dispenser are respectively provided with a sensor array module for collecting density data of the oil therein; the sensor array module includes a plurality of oil density sensors; the sensor array modules are communicated with the communication management machine; the built-in data processing module receives and processes data from the metering module, the level gauge and the sensor array modules respectively.

Abstract: The present application discloses a metering system for calculating a real-time profit or loss of a gas station, including a metering module, a level gauge of the oil tank, and a communication management machine with a built-in data processing module; the metering module and the level gauge are respectively communicated with the communication management machine; the oil tank, an oil pipeline of the oil tank and an oil inlet of the fuel dispenser are respectively provided with a sensor array module for collecting density data of the oil therein; the sensor array module includes a plurality of oil density sensors; the sensor array modules are communicated with the communication management machine; the built-in data processing module receives and processes data from the metering module, the level gauge and the sensor array modules respectively.