Common malfunctions and their elimination methods of concrete batching plant measurement system

Symptoms:

Measuring misalignment is often shown as in using the scale instability, low drift, linear failure.

Analysis:

Cause not summed up by 3 factors: human factors, electrical appliances, and other factors.

Treatment methods:

1, human factors in the following three aspects:

① Concrete batching plant process, when said material in the hopper reaches the set value, the feeding belt conveyor automatically stops (pneumatic feed door closed), but there are still some items from falling into the hopper, this is part of the weight of the material known as gap. In order to ensure the accuracy of ingredients, General amendments to the material set drop value.

② When hopper discharge, when hopper said weight reached set value stop discharging at the beginning. But actual production on the wet material adhered to the hopper, then batching controller was unable to complete unloading. Thus, in production, the initial set value added an addition to human error to offset the weight of adherent, generally by installing vibrator on the hopper to reduce the error value.

③ pay attention to sensor installation location or direction and weigh parts of the connection, such as installation location is not correct, or should become hard-wired for soft connections can lead to inaccuracy

2, electrical leads to the following three aspects:

① If you find circuits problems check each sensor wiring connector for normal, there is no wear broken, there is no damping phenomenon at the joint. Such as reading to adjust to the desired number, or reading all appear after loading small, should check whether the wiring is incorrect, such as incentive polarity reversed, signal lines against, power cord, signal cable, or other failure. Display large values, drift and instability, may be bad sensor, you should replace the sensor. If not that is a sensor problem or wiring problem, best thing to do is remove the sensor to control indoor test directly to the measuring instrument, it is easy to solve the problem. concrete batching plant now each scale, being mostly used multiple (usually three) sensor of mutual support, if the judgments are sensor problem, it may be one or more of these problems, the best way is only a test, that is, take a look at is normal, and then try another, may find what went wrong.

② a professional electrician can sensor resistance and the voltage after power on, General sensor has 5 wires, 1 shield wire, 2 for power excitation lines, 2 for signal lines, such as resistance or voltage deviation is too large, the sensor is damaged and should be replaced. But note that even if the input and output resistance is normal does not mean that there is no problem, because the sensor is very sensitive, most of the problem is the sensor number is erratic, its resistance to normal, but unstable, because most is internal damage or strain the water.

③ the tell is inside the control box amplifier (or meter) reason is the perimeter road. Method is very simple, using the swap method, because there will be more of the same in a control system of measuring instruments, shifted the problem to the normal way of try it, if you still have a problem may be the external circuit problem if normal is the problem of measuring instruments.

3, other factors weighing bucket is stuck or other causes scales can't move, the force of these will cause the feed sensor error, although with all ingredients after setting and weighing display values, but the actual material is much larger or smaller than this value. Check lock and, if necessary, re-calibration.