What is a weighing sensor? Common faults and their solutions

What is a weighing sensor? Common faults and their solutions

A weighing sensor is a device that can convert the mass signal of an object into a measurable electrical signal for output. It has various styles, such as S-shaped, cantilever type, spoke type, etc., and can be divided into various types based on the conversion principle, such as photoelectric type, hydraulic type, electromagnetic force type, etc.
In terms of working principle, a weighing sensor senses the gravity of the object being measured and converts it into a measurable output signal in a certain proportion. Its performance indicators mainly include linear error, hysteresis error, repeatability error, etc., which are crucial for ensuring the accuracy of the sensor.
According to the regulations of the International Organization for Legal Metrology, the error band of the sensor must be controlled within 70% of the error band of the weighing instrument to ensure the accuracy of the weighing sensor. Meanwhile, manufacturers can adjust the various error components of the sensor to further optimize its accuracy.
For shear beam weighing sensors, their working principle is based on the deformation of elastic bodies under stress. When an elastic body is subjected to force, it not only generates normal stress, but also shear stress caused by shear force. This shear stress is indirectly obtained by measuring the principal stress perpendicular to each other at a 45 degree angle to the central axis of the I-beam.

Regarding common faults and their solutions of weighing sensors, the following are some common situations:
1. Display screen flashing fault: This may be caused by improper placement of the scale pan, interference from moving objects, or damage to the analog switch integrated block. The handling method includes checking the position of the scale pan, removing interfering objects, and replacing damaged integrated blocks.
2. Unstable weighing display: It may be caused by mechanical hysteresis, poor resistance strain gauge characteristics, or elastic body problems. The handling methods include inspecting and replacing problematic components, as well as optimizing the mechanical structure.
3. No weight indication fault: First, check if the power supply is normal, then gradually inspect the amplification circuit, power supply bridge circuit, and other components to locate and repair the fault point.
4. There may be zero drift, non return to zero, and jumping words on the display: it may be caused by virtual connection, open soldering phenomenon, or unstable power supply voltage of the weighing sensor bridge. The handling methods include checking the bridge connection, repairing virtual contacts, and stabilizing the power supply voltage.
5. Inaccurate weighing indication: Reasons may include damage to the elastomer, high supply bridge voltage, or environmental factors. The handling methods include repairing or replacing the elastomer, adjusting the supply bridge voltage, and improving the usage environment.
6. Creep phenomenon: mainly due to problems with the bonding layer, such as improper selection of bonding adhesive, humid bonding environment, etc. The processing methods include selecting appropriate adhesive, optimizing the bonding process, and improving the bonding environment.
When dealing with these faults, it is necessary to carefully inspect the appearance of the weighing sensor and conduct step-by-step testing and analysis based on its working principle. Through careful observation and scientific analysis, faults can often be quickly eliminated.