A Preliminary Analysis of Interference Sources in Portable Vehicle Weighing Scales Detection Devices

A Preliminary Analysis of Interference Sources in Portable Vehicle Weighing Scales Detection Devices

Keywords: portable vehicle weighing scales, axle weighbridge, Vehicle Weigh Pads, axle scale, truck mounted scales

Portable Axle Scales overweight and overloaded vehicle weighing detector:

The full name of the car weighing instrument is portable over limit and overload car weighing detector, also known as portable over limit and overload detector, road mobile overload control instrument, portable axle scales, etc. The portable axle scales is one of the overload control instruments and an essential item for protecting cars. Its advantages lie in its thin tabletop, light weight, and easy portability, earning it the nickname of a notebook in electronic car scales. It can regulate over limit transportation and is an essential tool for road administration departments to effectively curb vehicle overloading and over limit. Portable axle scales advantage lies in its light weight and ease of carrying. Used for highway management of overloaded transportation, it is an essential tool for road traffic police departments to effectively curb vehicle overloading and overloading.

The weighing principle of portable vehicle weighing scales:

portable vehicle weighing scales, also known as axle weighbridge, is mainly used in the fields of automobile manufacturing and automobile inspection. By dynamically passing or stationary the automobile on a weighing platform of a certain width, the weight of each wheel is weighed from the Vehicle Weigh Pads platform, the weight of the automobile axle and the overall weight are accumulated, and the stability of the automobile design is judged according to certain standards and other functions. It is one of the commonly used testing standard tools in the fields of automobile manufacturing and automobile inspection!

The working principle of the portable vehicle weighing scales is as follows: when the car tire applies heavy pressure to the weighing machine, the axle weighbridge sensor releases a voltage signal, and the output signal is proportional to the weight of the tire. The signal is transmitted to the amplifier for amplification, and then converted into a digital signal by the analog-to-digital converter for display on the monitor. The single Vehicle Weigh Pads board obtains the wheel weight value of the car, and the two Vehicle Weigh Pads boards are the axle weight. Based on the axle type of the car, the total weight of the car can be accumulated.

The working principle of the weighing load cell of the axle weighbridge is as follows: when the weight platform is deformed under pressure, the resistance value of the resistance strain gauge in the sensor is changed, and the output of the signal is changed.

There are two types of sensors used for axle weighbridge platform sensors: embedded structure sensors and integrated structure sensors. Currently, embedded structure sensors are more popular in the market. Embedded structure sensors have advantages such as high voltage resistance and accuracy compared to previous integrated sensors.

The working principle of the weighing sensor of the portable vehicle weighing scales is as follows: when the Vehicle Weigh Pads platform is deformed under pressure, the resistance value of the resistance strain gauge in the sensor is changed, and the output of the signal is changed.

There are two types of sensors used for Vehicle Weigh Pads platform sensors: embedded structure sensors and integrated structure sensors. Currently, embedded structure sensors are more popular in the market. Embedded structure sensors have advantages such as high voltage resistance and accuracy compared to previous integrated sensors.

The performance of the weighing sensor and weighing display instrument in the portable axle scale overweight and overloaded vehicle weighing detection instrument system has taken a big step forward in intelligence, multifunctionality, integration, high precision, and high resolution, thereby improving the weighing accuracy and resolution of the electronic weighing system.

Due to the harsh industrial environment conditions in which most portable vehicle weighing scales over limit and overloaded vehicle weighing and testing devices are located, their instrument systems are often affected by harmful factors such as electromagnetic radiation, electrostatic induction, electromagnetic pulses, lightning discharges, high-frequency noise, and ground potential imbalances. These interferences enter the signal circuit of the measurement system through certain coupling methods and channels, causing errors in useful signals and distorting measurement results, resulting in a decrease in the weighing accuracy, sensitivity, and reliability of the instrument system. In severe cases, the axle scale instrument system may even be completely inoperable. Therefore, corresponding anti-interference technologies and measures must be adopted to effectively suppress various interferences, minimize the impact and harm of interference, and ensure the accuracy, reliability, and stability of the weighing and indication of the truck mounted scales.

Interference sources and coupling channels in industrial environments: Interference occurs from interference sources, and there are various types, reasons, and pathways for its introduction. There is a single interference, as well as complex interference caused by multiple overlapping reasons. The ground surface where a portable vehicle weighing scales detector is placed may not necessarily have an ideal zero potential, such as grounding devices for various electrical equipment, lightning rods and grounding piles for buildings and structures, which can cause significant differences in ground potential and can change at any time. Therefore, if the grounding device of the portable vehicle weighing scales detector is not properly set, interference will be introduced by the grounding wire, which is mainly introduced into the electronic weighing system through the following ways and coupling pathways.

There are many sources of interference for the axle weighbridge, such as the requirement for power supply voltage: unstable power supply voltage and too many interference sources can cause confusion in the logic function of the portable axle weighbridge, resulting in unstable operation of the entire portable axle load gauge; Tips for use: Improper operation of the axle weighbridge may potentially damage its functionality.

Now let's analyze several main sources of disturbance:

1: High frequency mechanical vibration of the weighing load cell (frequency<200Hz):

If the weighing sensor of the portable vehicle weighing scales responds to it, vibration interference will be superimposed on the axle weighing curve.

2: Bending deformation vibration in the longitudinal direction of the axle scale platform:

When customers choose an portable vehicle weighing scales, it is not necessarily better to have a smaller or larger scale. It depends on the low vibration frequency of the axle vehicle, which cannot be eliminated by low-pass filtering and has a significant impact on the accuracy of dynamic weighing.

3: When the vehicle is not turned off, the vehicle itself vibrates: the axle mass and shock absorber spring group, the heavy axle mass is greater than 10t, the vibration frequency is less than 2.5Hz, the theoretical axle weighing curve period is greater than 0.4s, and the effective weighing time of the vehicle on the weighing Vehicle Weigh Pads platform is mostly less than 0.4s. This vibration effect is difficult to eliminate. When a vehicle travels rapidly or accelerates over uneven roads, strong vibrations have a significant impact on the weight of the vehicle; But when the vehicle passes over a flat road at low speed and constant speed, the amplitude is small.

Precautions for using a portable vehicle weighing scales:

1: Sensors and portable vehicle weighing scales must be reliably connected and kept away from strong electric and magnetic fields. Sensors and car weighing devices must be kept away from highly corrosive objects and flammable and explosive materials.

2: Do not use in the presence of flammable gases or vapors.

3: In areas with frequent lightning strikes, reliable lightning arresters must be installed to ensure the personal safety of operators and prevent lightning damage to portable vehicle weighing scales and corresponding equipment.

4: Sensors and axle weighbridge are all static sensitive equipment, and it is necessary to take effective anti-static measures in their application. It is strictly prohibited to carry out welding operations or other strong electric field operations on the Vehicle Weigh Pads platform; During thunderstorm season, reliable lightning protection measures must be implemented to prevent damage to sensors and axle weighbridge caused by lightning strikes, ensuring the personal safety of operators and the safe operation of axle weighbridge and related devices.

5: Before plugging and unplugging the axle weighbridge and connecting it to external equipment, cut off the power supply of the axle weighbridge and corresponding equipment! Before connecting the sensor, please cut off the power supply of the axle weighbridge (turn off)! Before plugging or unplugging the communication cable, cut off the power supply to the car weighing device and the upper computer!

The above are several precautions for using a portable vehicle weighing scales. During use, it is necessary to standardize the operation process, prevent accidents from the source, and avoid unnecessary losses!