What are the common reasons for the insufficient accuracy of chain code calibration for electronic belt scales, and how can they be resolved?

As an online automatic weighing and metering device, electronic belt scales require regular, reasonable, and precise calibration methods to maintain their measurement accuracy and stability. Inaccurate or infrequent calibration will inevitably affect the application accuracy of the belt scale.

Chain code calibration is a common and convenient method for calibrating electronic belt scales, widely used in practice. The chain code calibration device consists of precisely measured chain codes with known mass per unit length, linked together to form a closed loop and hung above the belt scale frame.

During calibration, a lifting mechanism places the chain codes onto the belt, where the belt drags the chain code blocks to simulate flowing materials. The theoretical weight is calculated based on the belt length and the weight per meter of the chain code, and this is compared with the weight displayed on the belt scale monitor to perform the calibration.

Various factors can lead to inaccurate calibration when using chain codes for electronic belt scales, including environmental and human factors.

When encountering inaccurate chain code calibration during the weighing process with electronic belt scales, understanding the common causes and solutions can help achieve high-precision calibration work and better improve the measurement accuracy and stability of the belt scale.

The causes and solutions for inaccurate chain code calibration of electronic belt scales mainly include the following points:

1. Calibration errors caused by the electronic belt scale itself:

   - Deformation of the belt scale's weighing bridge, or faults/abnormalities in the weighing sensor, speed sensor, or instrument.

   - Solution: Refer to the technical documentation provided by the belt scale manufacturer to check if the parameters of the weighing sensor, speed sensor, and instrument are normal, if the wiring is correct, and if the fasteners are loose.

2. Calibration errors caused by contamination in the working environment:

   - Material jamming between the weighing bridge of the belt scale and the belt conveyor frame, or belt dampness due to operational reasons, can cause additional (increased or decreased) weight on the weighing sensor.

   - Solution: Before performing chain code calibration, clean the material and dust between the weighing bridge of the belt scale and the belt conveyor frame, and ensure the belt is dry, free of accumulated material, moisture, and other foreign objects.

3. Calibration errors caused by belt deviation on the belt conveyor:

   - Belt deviation can occur due to improper installation, misaligned belt splicing, material buildup on the belt conveyor rollers causing misalignment, or incorrect material feeding points, resulting in additional (increased or decreased) weight on the weighing sensor.

   - Solution: Recalibrate the horizontal alignment of the rollers from the first two sets to the last two sets in front of the belt scale, and correct the belt deviation within an acceptable range.

4. Calibration errors caused by human factors:

   - Inaccurate measurement of the belt length and the time for a complete cycle (usually one full circle) of the belt conveyor.

   - Solution: Re-measure the length of one full circle of the belt and its running time, ensuring the data is accurate and using the average value for calculations.

5. Calibration errors caused by the chain code calibration device:

   - Possible causes:

(1) The mass per unit length of the chain code should be a constant value when simulating materials to test the belt scale, but variations may occur due to manufacturing or installation issues.

(2)Improper installation of the chain code device or insufficient chain code length may result in incomplete coverage of the effective weighing area of the belt scale, affecting the mass per unit length of the chain code.

(3) Insufficient mechanical strength of the chain code device and belt scale may cause significant vibration during belt operation, leading to fluctuations in the weight signal of the material on the effective weighing section of the belt scale and inaccurate weight measurements by the weighing sensor.

   - Troubleshooting solutions:

(1)Calibrate the mass of the chain code to ensure its error is within an acceptable range.

(2)Thoroughly inspect the installation specifications of the chain code device to ensure the installation position deviation is within a reasonable range.

(3)Adjust the material coefficient in the instrument to correct the error, and then recalibrate the belt scale before performing physical calibration.

(4) Reinforce the belt conveyor frame around the weighing bridge of the belt scale with channel steel and increase the number of foundation bolts for the belt conveyor support to reduce vibration.

Guonuo Technology not only provides users with various types of electronic belt scales but also configures precisely calibrated circulating chain codes, winch chain codes, hidden box chain codes, etc., according to user needs. Additionally, we offer chain code calibration operation training to help users correctly and reasonably use belt scales and scientifically adopt chain code calibration methods.