Dynamic checkweigher as known as online checkweigher,automatic check weight machine,high speed check weigher machine,high precision weight sorting checkweigher and etc.
The dynamic checkweigher may have inaccurate weighing and product misjudgment after long-term use. Generally, we have to solve this kind of problems through the calibration of the weight control instrument. But sometimes the checkweigher cannot be restored to normal no matter how it is calibrated. At this time, we have to check in detail from the weighing part of the dynamic checkweigher, and the core component of the weighing part is the load cell.
At present, the checkweigher generally uses resistance strain gauge load cell (analog) as the core component of the weighing mechanism. It uses the Wheatstone bridge principle to convert the weight signal into a linearly changing electrical signal. There are conventionally four lines and the input is 5 -10V excitation voltage (supply voltage), the output is a weight signal with "mV" as the unit. So how to judge the quality of the weighing sensor of the dynamic checkweigher?
The judgment method is as follows:
Observe whether the sensor is deformed or cracked. If these conditions occur, you need to contact the manufacturer to replace the new sensor in time.
2. Line input and output measurement method
Find the sensor connection terminal in the checkweighing controller and determine the sensor connection circuit.
Under normal circumstances, the excitation voltage (between EXC+ and EXC-) is 5-10V, and the output voltage (between SIG+ and SIG-) is close to 0 when the device is empty, which is less than the maximum output of the sensor. (The maximum output of the sensor = excitation voltage * sensor sensitivity, the sensitivity of the checkweigher sensor is mostly 2mV/V), if it exceeds this range, contact the service provider to apply for a replacement of the sensor.
3. Sensor resistance measurement method:
Measure the resistance of the sensor, and judge the sensor by the resistance
(1). Input resistance≧output resistance>bridge resistance
(2). Generally, the bridge resistances are equal or equal to each other
(Note: The input resistance is the resistance between EXC+ and EXC-, the output resistance is the resistance between SIG+ and SIG-, and the bridge resistance is between EXC+ and SIG+, EXC+ and SIG-, EXC- and SIG+, EXC- and SIG- Resistance between)
The above is the judging method of the load cell of the checkweigher. With these three statements, it is easy to know whether the load cell has a problem. It should be noted that the load cell is not so easily damaged under normal use. Many failures are caused by improper use of the checkweigher, which overloads the sensor. Therefore, in the process of using and disassembling and maintaining the checkweigher, we should try our best to avoid heavy objects from hitting and bumping, and operate strictly in accordance with the checkweigher range.
Shanghai Shigan Industrial Co,.Ltd has years of experience in weighing and packaging areas.It provides customers with cost effective packaging and weighing equipment.The quality of product is reliable and stable.If you have any questions,please contact me.