A load cell is actually a device that converts a mass signal into a measurable electrical output. When using sensors, we must first consider the actual working environment where the load cell is located. This is very important for the correct selection of the load cell. It is related to the normal operation of the sensor, its safety and service life, as well as the reliability and safety of the entire weighing instrument. There are qualitative differences between the old and new national standards in the basic concepts and evaluation methods of the main technical indicators of weighing sensors.

Judgment of weighing sensor quality:

After long-term use, the weighing equipment may appear inaccurate weighing. Usually, we have to solve these problems by calibrating the weight controller. But sometimes, no matter how calibrated, the scale doesn't return to normal. At this time, we must carry out detailed research from all aspects of the weighing mechanism, and the core component of the weighing mechanism is the weighing sensor.

The current weighing equipment generally adopts the resistance strain gauge weighing sensor (analog) as the core component of the weighing mechanism. It uses the Wheatstone bridge principle to convert the weight signal into a linearly varying electrical signal. The conventional has four lines, the input is 5-10V excitation voltage (power supply voltage), and the output is a weight signal in "mV". The following editor will show you how to judge the quality of a load cell:

一、 Observe:

Observe whether the sensor is deformed or cracked. If these conditions occur, you will need to contact the manufacturer to replace the sensor with a new one.

二、 line input and output measurement method:

Locate the sensor connection terminal in the weighing controller (weighing instrument) and determine the sensor connection circuit.

In general, the excitation voltage (between EXC+ and EXC-) is 5-10V, and the device space-time output voltage (between SIG+ and SIG-) is close to 0, which is less than the maximum output of the sensor. (The maximum output of the sensor = excitation voltage * sensor sensitivity, the sensitivity of the automatic weight scale sensor is mostly 2mV/V), if you exceed this range, please contact the service provider to apply for the replacement of the sensor.

三、 Sensor resistance measurement method:

Measure the resistance of the sensor and judge the quality of the sensor by the resistance.

1: Input resistance ≧ output resistance > Bridge resistance

2: Under normal circumstances, the bridge resistance is equal or equal

(Note: The input resistance is the resistance between EXC+ and EXC-, the output resistance is the resistance between SIG+ and SIG-, the bridge resistance is the resistance from EXC+ to SIG+, EXC+ to SIG-, EXC- to SIG+, EXC- to SIG-)

The above is the judgment method of the weighing sensor in the weighing equipment. It should be noted that the load cell is not so easily damaged under normal use. Many failures are caused by overload of the load cell caused by improper use of the scale body. Therefore, in the process of using, disassembling and maintaining the weighing equipment, heavy objects should be avoided as far as possible, and the operation should be strictly in accordance with the weighing range of the equipment.