About the common faults of electronic platform scales:

　　Electronic platform scale is one of the electronic weighing instruments. It has the characteristics of fast, simple, intuitive, high accuracy, etc., and has been widely used in various enterprises and other fields. However, it is inevitable that there will be failures in use, which requires our metrology and maintenance personnel to have certain theoretical basic knowledge and practical maintenance capabilities. Let's talk about some methods, steps and other issues of the inspection, analysis and handling of electronic platform scale faults in conjunction with the actual work.

　　One, the composition and working principle of the electronic platform scale

　　(1) The structure of the electronic platform scale The electronic platform scale is mainly composed of three parts: weighing display instrument, weighing sensor, and scale body. Among them, the scale body is the mechanical, force-transmitting reset system between the object and the conversion element, including the carrier that accepts the load of the object, the force-transmitting reset mechanism, and the limit device. It is the main load-bearing component of the electronic platform scale. Play the role of bearing the weight of the object. The weighing platform and the rotating force mechanism are responsible for accurately transmitting the weight of the object to the load cell.

　　(2) Principle of operation Put the weight on the weighing platform of the electronic platform scale. Under the action of the gravity of the object, the elastic body of the load cell deforms, and the weight transfers the weight to the load cell through the scale body, and the sensor converts the weight signal Is the corresponding mV voltage signal. The signal is amplified by a preamplifier, filtered by a filter, and A/D converted. After the weight signal is processed by a microprocessor, the digital display directly displays the weight.

　　2. Analysis and treatment of common failures of electronic platform scales

　　There is no display and no sound when starting up. Fault analysis: "No display" from the circuit analysis means a fault on the display circuit, and no sound means a fault on the buzzer circuit. The probability of these two failures occurring at the same time is relatively low. Therefore, the general fault will appear on the power supply circuit.

　　Exclude: a. Whether the voltage at the input terminal of the measuring instrument is normal.

　　B. Whether the voltage at the input and output terminals of the instrument is normal.

　　C. Whether the bridge voltage input and output terminal voltage is normal.

　　D. Whether the output of the rectifier circuit is normal. Generally, this type of fault can definitely be found in the above four fault sources.