1. From a material perspective, a platform scale must have sufficient rigidity and strength. Material thickness is also a key factor in determining its quality.

2. The quality of a platform scale's load cell directly affects its accuracy and stability. Generally, consider sensors from reputable brands, such as Mettler Toledo, HBM, Silver Lake Weighing, Zemic, and Vipoo.

3. The sealing quality and anti-interference capabilities of the junction box determine the stability of the scale.

4. The quality of the welding process directly affects the angular error during platform weighing.

5.The quality of the surface coating affects the durability of the platform scale. Vipoo and Silver Lake weighing platform scales use a plastic spraying process, which can withstand salt spray tests 3-5 times longer than paint.

The welding process for a platform scale involves several key steps, including material selection, structural assembly, welding techniques, and quality inspection. The following are the specific steps and key technical points:

Material Preparation and Pretreatment

Material Selection: The scale body is typically made of carbon steel or stainless steel (e.g., 304/316). The plate thickness must be determined based on the load-bearing requirements.

The supporting structure must be made of the same material as the scale body to ensure corrosion resistance.

Surface Treatment: Before welding, remove impurities such as oil and rust from the welded area. Stainless steel also requires pickling and passivation to enhance corrosion resistance.

Grooving: For thicker plates (e.g., >6mm), a V- or X-shaped groove is required, with a 60° angle, a blunt edge of 0-1mm, and a gap of 0-1mm.

Welding Process

Welding Method:

For carbon steel scale bodies, argon arc welding or submerged arc welding is commonly used. For stainless steel, argon arc welding is preferred to reduce the heat-affected zone.

When welding multiple layers, use a smaller diameter electrode (e.g., 3.2mm diameter) for the first layer. The number of subsequent layers should be adjusted based on the leg size (single-layer welding: <8mm, multi-layer welding: 8-10mm, multi-pass welding: >10mm).

Parameter Control:

Current and voltage should match the material thickness. Reduce the current by 10-15% when welding vertically or overhead.

Welding should be performed symmetrically from the center toward the ends to control deformation.

III. Post-Weld Treatment and Inspection

Surface Treatment: Welds should be polished and ground. Stainless steel should be sandblasted or sprayed with anti-rust paint.

Quality Inspection:

Appearance Inspection: Check for defects such as cracks and pores.

Non-destructive Testing: Ultrasonic or magnetic particle testing of the weld's internal quality.

Weighing Test: Use standard weights to verify accuracy.

IV. Safety and Operating Procedures: Before welding, check the grounding and insulation of the equipment. Wear protective equipment in humid environments.

When welding stainless steel, ensure adequate ventilation to prevent inhalation of harmful gases.

Six-wire load cells offer significant advantages over four-wire load cells in terms of measurement accuracy, interference immunity, and long-distance transmission stability. The following are specific reasons:

I. Voltage Compensation Improves Accuracy

Real-time Voltage Feedback: Six-wire load cells transmit the actual voltage received by the sensor to the weighing instrument in real time via the SENSE+ and SENSE- feedback lines. The instrument dynamically adjusts the excitation voltage accordingly to offset voltage loss caused by line resistance, ensuring that the measurement result strictly corresponds to the actual weight.

High Impedance Matching: The feedback line matches the impedance of the sensor's internal high-impedance circuit to the instrument's, reducing signal transmission loss and making it particularly suitable for long-distance measurements. Long-distance (e.g., >10 meters) or high-precision (e.g., Class C1) applications

II. Enhanced Anti-interference and Stability

Environmental Adaptability: In complex environments such as temperature fluctuations, electromagnetic interference, or line aging, the feedback line monitors and corrects signal drift in real time, improving system stability by over 30%.

Optimized Resolution: By adjusting the feedback voltage, the instrument can dynamically expand its measurement range (e.g., from 0-10kg to 0-100kg) while maintaining high resolution (e.g., 0.1g).

III. Advantages in Industrial Applications

Long-Distance Transmission: In factories where sensors are located far from PLCs/instruments, a six-wire system reduces signal attenuation and avoids measurement errors caused by voltage drop in a four-wire system (e.g., reducing ±0.5% errors to ±0.1%).

Precautions for Foundation Pit Platform Scale Installation

1. Foundation Construction Requirements

Pit Dimensions and Flatness: The foundation pit must be constructed strictly according to the drawings, ensuring the dimensions are square and avoiding mold expansion or depth deviations. Failure to do so will make installation of the scale difficult and affect the aesthetics.

Drainage Design: Drainage pipes must be installed to prevent rainwater from accumulating and soaking the sensor, especially in rainy or humid areas.

Bearing Capacity and Curing: The bearing capacity of the underlying soil must be ≥117.6 kPa (12 t/m²). The concrete curing period must be at least 28 days. The scale platform must not be installed until it reaches the required strength.

2. Installation Environment and Location

Vibration and Interference Protection: Keep away from strong electromagnetic interference sources such as high-voltage power lines and substations. If this is unavoidable, shield the signal line with a metal mesh protective tube.

Ventilation and Maintenance: Access holes (for sensors installed on the side) and ventilation space must be reserved within the foundation pit to prevent damage to the device due to humidity.

Approach Design: Upper and lower approaches must be straight and of a length that matches the scale. Sharp bends and gentle slopes are prohibited to minimize vehicle impact.

3. Safety and Commissioning

Grounding Protection: Ground resistance must be less than 4Ω, and all equipment must be grounded using standardized methods.

Calibration and Ambient Conditioning: After installation, allow the device to acclimate to the environment for at least 30 minutes. Calibration is required before initial use.

Platform Scale Weighing Indicator Selection Guide (2025 Latest Edition)

1. Matching the Indicator Type to Functional Requirements

‌Basic Display Type‌

Suitable for simple weighing scenarios (such as warehouse floor scales) requiring only real-time weight display, affordability, and support for I/O expansion (e.g., printer connection).

Typical Applications: Static weighing scenarios (such as floor scales and electronic scales). Note that these transmitters have slow sampling speeds and are not suitable for dynamic weighing.

Industrial Control

When integrating with a PLC/DCS system, choose a weighing transmitter with RS485 or PROFIBUS DP communication. These transmitters are suitable for industrial scenarios such as silo weighing and assembly line control.

Key Parameters: Signal conversion accuracy (such as 4-20mA analog output) and interference immunity.

High-Precision Control

For laboratories or the pharmaceutical industry, choose a weighing controller that supports checkweight statistics and multiple range switching (such as 0.1g-100kg). Recommended models include the Ohaus TCS-CKW3R55 and the Silver Lake SL-131PL/SL-13SS.

2. Adapting the Instrument to Environmental Conditions

Humid/Corrosive Environments

Select an instrument with an IP66 or higher protection rating. The housing should be made of stainless steel or ABS with a waterproof coating to prevent liquid penetration and short circuits.

3. The sensor junction box must meet IP55 standards and feature a waterproof elbow design.

Environmental conditions requiring electromagnetic interference

Keep away from high-voltage power lines or substations, or use signal cables with metal shielding (e.g., six-core sensors).

For dynamic weighing applications (such as belt scales), select an instrument with strong anti-interference capabilities and a sampling rate of 50Hz or higher.

Environmental conditions requiring temperature fluctuations

Wide-temperature sensors (-20°C to 60°C) are suitable for outdoor use or cold storage; attention should be paid to temperature compensation.