The main reasons for the failure of the measuring system of concrete mixing station come from five aspects: the failure of the batching measuring device, the failure of the weighing device, the failure of the loading device, the failure of the unloading device and the failure caused by human factors.

The batching metering device is faulty
1. The running indicator is faulty
● Fault performance: the running indicator light is not bright
● Fault causes: first, the control system is not normal, internal failure caused by the indicator light is not bright; Second, the 24V DC power supply is not connected smoothly, or the positive and negative poles of the power supply are incorrectly connected, or the power supply line is aging and falling off, so that the power supply system cannot operate normally; Third, the line contact is poor.
● Troubleshooting methods: first, regularly check the batching machine, to ensure the normal operation of each system batching machine; Second, check the power connection and line communication system in time.

2. The batching machine is faulty
● Failure performance: the set value of the batching machine does not match the actual weighing value.
● Fault causes: first, the aggregate itself is not homogeneous easy to cause the center of gravity offset, so that the weighing hopper and aggregate center of gravity is not consistent, resulting in metering failure; Second, the setting of relevant parameters of the batching machine is inconsistent with the actual material value, on the one hand, it may be unreasonable to set parameters, on the other hand, it may show that the scale is not accurate; Third, the scale bucket is stuck, it is difficult to move freely, resulting in inaccurate weighing.
● Fault handling method: first, choose the balance bucket center of gravity is not biased and can move flexibly as a measurement tool, strengthen the aggregate center of gravity and balance bucket center of gravity consistency test; Second, check the accuracy of the scale regularly to reduce the weighing error.

Weighing device failure
1. The sensor is faulty
● Failure performance: the display of data volatility is large, the county has instability.
● Cause of failure: first, the sensor plug loose, resulting in poor contact; Second, the wear and short circuit phenomenon caused by sensor circuit wear.
● Fault handling method: according to the sensor output parameters to determine whether there is a fault and deviation, sensor fault measurement indicators for the output resistance and sensing voltage.

2. The weighing scale is faulty
● Fault performance: the reading is not allowed, the difference is large.
● Fault causes: first, hopper activity size, hopper stuck; Second, positive and negative wire misplacement; Third, the connection between the drain pipe and the tank is welded, and the soft connection becomes a hard connection; Fourth, the feed pipeline material aging.
● Fault treatment method: first, the scale bucket drain pipe and tank joint welding segmentation processing, restore the measurement accuracy; Second, properly check the hopper, line connection and sensor operation, ready for maintenance.

The cement feeding device is faulty
● Fault performance: the cement inside the feeding conveying pipeline is solidified, blocking the pipeline and causing the feeding device failure.
● Fault causes: first, the influence of climate and environment, rainy season and pipeline aging damage, easy to accelerate cement solidification; Second, feeding conveying equipment work intensity is too large to cause machine paralysis; Third, the cleaning type of the feeding equipment is poor, and the long-term accumulation of cement residue causes device failure; Fourth, the motor of the screw conveyor is burned out.
● Fault treatment method: first, timely cleaning and treatment of the cement feeding device residual, especially in rainy season, to prevent cement coagulation; Second, strengthen the installation and maintenance of screw conveyor, such as setting a reasonable installation Angle, the general tilt Angle is set to about 40 degrees, timely oil cup and reducer gear refueling; Third, disassemble the maintenance motor, open the inspection window of the screw conveyor, check the cement solidification and start the motor, excluding the cement in the pipeline.

The discharging device is faulty
● Fault performance: unloading equipment stops running, can not discharge
● Cause of failure: first, the discharge button operation failure and damage; Second, the setting of unloading equipment parameters is unreasonable; Third, metering element failure, such as solenoid valve element failure, cylinder overdue use caused air leakage phenomenon.
● Troubleshooting method: reset equipment parameters, check the safety performance of the relevant measuring components, regular replacement and maintenance of aging parts.

Faults caused by human factors
● Failure performance: first, can not correctly use measuring instruments; Second, hopper stuck; Third, the installation Angle of screw conveyor is unreasonable; Fourth, there is a large deviation of material drop value; Fifth, wet material is attached to the hopper, or the hopper weight does not reach the set initial value to stop unloading.
● Cause of failure: first, screw conveyor maintenance and cleaning work is not in place, equipment is cement solidification phenomenon; Second, the way and method of installation equipment is not reasonable, resulting in the screw conveyor installation Angle is too large or too small; Third, due to human negligence, the stones around the hopper are stuck, thus weakening the flexibility of the hopper; Fourth, the correction process of the drop value is not careful; Fifth, the relevant factors affecting the initial value of the hopper are ignored, or the actual initial value is less than the set initial value due to improper operation.
● Fault treatment method: first, in the hopper initial value is small, should be artificially set an error to offset the weight of the wet material attached to the hopper, or add a vibrator on the hopper to reduce the attachment, reduce the initial error; Second, in order to improve the accuracy of ingredients, seriously consider the drop value, do a good job of material drop value correction work; Third, strengthen the concrete mixing station staff post training, strengthen the operation of staff assessment.

The reasons for the failure of the batching and measuring system of concrete mixing station come from many aspects, including the influence of external working environment, human factors, and the influence of the equipment failure of the measuring system. Therefore, in order to reduce the frequency of failures to improve fault rescue and treatment, the first thing you need to properly identify faults, based on the experience of breakdown maintenance area, and to detect the failure zone city, locating failure element, finally considering various factors that influence the measuring element down to do a good job of maintenance, record and feedback. In addition, human factors are one of the main causes of failure, so strengthening the maintenance skills of operators and strengthening the skills training of operators is an important means to reduce the probability of accident accident and reduce the frequency of failure.