​Analysis and treatment of uncommon failure of floor scale

Analysis and treatment of uncommon failure of floor scale
 Electronic scale load in use will often appear some problems of one kind or another, but some problems are rare and to handle and very difficult, often need a few days to deal with a problem, and what is not common fault and seldom met, once encounter also have to go through the detour his predecessors, wasted a lot of manpower material resources. How to correctly judge the cause of failure is a skill that maintenance personnel urgently need to master. Now we will engage in weighing instrument measurement verification maintenance for decades encountered a few rare typical cases, take out and share with you, perhaps to you can play a certain role for reference.

 Case 1. Fault manifestation: three sections of scs-120 electronic floor scale have a indexing value of d=20kg. It has not been installed for a long time. Under the condition of no wind, when the vehicle is on the weighing table, the meter shows a stable value. When the vehicle is removed from the weighing table, the meter does not return to zero, which is generally greater than two degrees.

 Search for reasons: I have checked many factors that can cause the instrument not to return to zero, such as:

 A. Whether there is too much dust and foreign matter under the scale, and it has not been checked;

 B. Check whether there is any uneven force on the sensor. Because the bridge sensor is used, the force on the ball of each sensor is basically the same.

 C. Check whether the connecting wires are damaged, and check whether the connecting wires of the sensors and instruments are not damaged;

 D. Check whether the terminals in the terminal box are fastened, and check that the terminals are connected normally without any false connection. Finally found in relatively large scales have a strange noise on the bus, after careful observation scale load weighing platform based on both ends with plane has a height of about 15 mm, weighing mesa is higher than the base both ends on the plane.

 When the scale weighing the car wheel contact weighing mesa moment, weighing platform making new sound, the judgment is:

 A. Because floor scale weighing mesa ends with the base plane is not a flat surface, cause the scale when weighing the car wheel contact when weighing the  impact of the mesa moment to a larger mesa;

 B. Due to the design defect of the electronic floor scale, the supporting point of the sensor at both ends is far away from the end point of both ends (more than  250mm), forming a moment arm with cross length;

 C. the actual weight of the scale platform is relatively light; When the impact force is larger, its longer arm will lift the other end of the scale platform under the action of the downward component force, and produce a certain  relative displacement, and with a "goo-dong" sound.

 Treatment method: to sum up, on-site treatment can only deal with the problem that the weighing-table of the floor scale is not on the same plane as the plane at both ends of the foundation. The method is to add 16mm steel plate (length × width × thickness =3.5m×1m×0.016) to the plane at both ends of the foundation. When the elevation difference is solved, the relative impact force is small. When the  vehicle removed the scale platform, the instrument is not reset to zero problem basically solved. Because did not completely solve other problems, occasionally will appear once, has not affected the normal use.