The automated gas meter testing line is a fully integrated, end-to-end automation system that combines automatic loading and unloading, multi-station parallel testing, automated data acquisition, intelligent sorting, and digital management. It enables unmanned, full-range testing of gas meters for air tightness, indication error, pressure loss, appearance, functionality, and other key parameters, thereby addressing critical pain points associated with manual testing, such as low efficiency, poor consistency, lack of data traceability, and heightened safety risks.

I. Core Objectives of the Plan

Full-process automation: From material intake to sorting, labeling, and storage, the entire operation is unmanned, with a cycle time of 10–15 seconds per unit.

High precision and high reliability: Detection accuracy meets national metrological standards, with a pass rate of ≥99.9% and a false-negative/false-positive rate of ≤0.1%.

Flexible manufacturing: Supports mixed-line production of multiple specifications, including G1.6, G2.5, and G4.0, with model changeover time ≤ 10 minutes.

Data-driven management: real-time upload of inspection data, automated judgment, one-click traceability, and integration with MES/ERP systems.

Safety and Environmental Protection: Enclosed testing combined with exhaust gas treatment eliminates the risk of gas leaks and ensures compliance with safety production standards.

II. Overall Architecture (Five Major Modules)

1. Logistics Transportation and Positioning System (Fundamentals)

Conveyor lines: double-deck high-speed chain conveyor / roller conveyor, with the upper deck for product transport and the lower deck for return pallets, featuring independent drive and precise positioning.

Loading and unloading unit:

Depalletizing/Feeding Robot: Automatically depalletizes, scans codes, and feeds materials, interfacing with AGVs and material racks.

Positioning and clamping: servo positioning combined with pneumatic clamping, with a repeat positioning accuracy of ±0.05 mm.

Pallet Management: RFID/barcode integration for automated phenotype identification and traceability of workstation throughput.

2. Core Testing Unit (Critical)

(1) Air-tightness Testing Station (Mandatory Inspection)

Principle: Negative-pressure/positive-pressure method combined with a differential-pressure sensor—inflate → stabilize pressure → maintain pressure → leak test → vent.

Test items: housing leakage, joint leakage, and internal leakage, with a detection sensitivity of 1×10⁻⁶ Pa·m³/s.

Cycle time: ≤15 seconds per unit, with multi-station parallel operation.

(2) Indication Error Testing Station (Metrological Core)

Standard instruments: sonic nozzle standard device / bell-type standard instrument, accuracy class 0.2.

Test items: indication errors at three flow points—minimum flow (Qmin), maximum flow (Qmax), and transition flow (Qt).

Automatic control: the computer automatically selects nozzles, switches flow rate points, collects data, and performs automatic judgment.

(3) Pressure Loss Testing Station

Test: Determine the total pressure loss of the gas meter at Qmax to verify compliance with the national standard.

Configuration: high-precision pressure sensor, automatic pressure regulation, and automatic data calculation.

(4) Appearance and Function Testing Station

Machine vision: inspection for surface defects (scratches, deformations, assembly misalignment), character/ barcode recognition, and pointer/counter reading.

Functional testing: solenoid valve on/off, pulse output, communication (M-Bus/RS485/NB-IoT), battery voltage, and tamper detection.

(5) Additional Testing (Optional)

Durability testing, high–low temperature cycling, waterproofing tests (IP ratings), and electromagnetic compatibility (EMC).

3. Intelligent Control System (Brain)

PLC + Industrial PC: Main controller, coordinating the timing and safety interlocks of each workstation.

Detection software:

Formula Management: Stores test parameters for multiple models and allows one-click switching.

Data Acquisition: Real-time acquisition of pressure, flow rate, temperature, time, and test results.

Automatic assessment: Automatically determine pass/fail according to national standards and generate a report.

Report Output: Certificate of Conformity, Nonconforming Product List, and Statistical Analysis Reports.

HMI touch screen: parameter setting, status monitoring, fault alarm, and operation guidance.

Safety Systems: Emergency Stop, Light Curtain, Door Interlock, Gas Leak Alarm, and Exhaust Ventilation Interlock.

4. Sorting and Post-Processing Unit

Automatic sorting: Pass/Fail/Reinspection items are automatically routed to different discharge outlets.

Automatic labeling and coding: print QR codes/barcodes (including model, serial number, test date, and test results) and apply the labels.

Material Cutting and Palletizing: Robots automatically palletize, pack, and seal boxes, seamlessly integrating with the finished-goods warehouse.

5. Environment and Auxiliary Systems

Environmental control: constant temperature (20±2°C), constant humidity, and stable voltage to ensure measurement accuracy.

Gas Supply: Pressure-regulated gas supply, emergency shutoff, leak detection, and exhaust gas recovery and treatment.

Data Management: Local storage combined with cloud backup, with support for MES/ERP integration to enable end-to-end traceability.

III. Fully Automated Testing Process (Closed Loop)

Material loading and scanning: robot unstacks → scans to identify model → loads material onto pallet → binds RFID.

Positioning and Conveying: The conveyor line transports pallets to each inspection station, where they are precisely positioned and clamped.

Parallel detection:

Air-tightness station: automatic inflation, pressure maintenance, and leak detection.

Indication station: automatically switches flow points, collects data, and determines errors.

Appearance/Function Station: Visual Inspection + Functional Testing.

Data Processing: The system automatically aggregates data, performs compliance assessments according to national standards, and generates test reports.

Automated sorting: conforming products → labeling → unloading and palletizing; nonconforming products → diversion to the rework area; re-inspected products → return to the inspection line for reinspection.

Data Upload: Inspection data is uploaded to the MES/database to enable quality traceability.

V. Key Technological Highlights

Multi-station parallel operation: simultaneous detection of air tightness, indication accuracy, and appearance, boosting efficiency by over 300%.

High-precision control: flow control accuracy of ±0.1%, pressure control accuracy of ±50 Pa.

Intelligent error prevention: automatic phenotype identification, prevention of mixed testing, and automatic rejection of non-conforming products.

Data Traceability: Each meter is assigned a unique ID, enabling full traceability of test parameters, results, timestamps, and personnel involved.

Unattended operation: 24-hour continuous operation, with a single operator capable of monitoring multiple production lines.

VI. Implementation Steps of the Plan

Requirements Survey: Clarify phenotypic specifications, production capacity, testing items, accuracy requirements, and site conditions.

Scheme Design: Layout Diagram, Equipment List, Takt Time Calculation, Control System, and Data Interfaces.

Equipment Manufacturing: Custom Non-Standard Solutions, Standard Equipment Integration, and Software Programming.

Installation and Commissioning: On-site installation, pneumatic and electrical wiring, accuracy calibration, and integrated system commissioning.

Trial Production: Small-batch trial production, parameter optimization, and personnel training.

Acceptance and Delivery: Acceptance of production capacity, precision, and stability; delivery of a complete set of documentation; after-sales support.

VII. Applicable Scenarios

Gas meter manufacturers (residential / industrial meters)

Institute/Research Institute of Metrology and Testing

Gas Company Calibration Center

Smart Meter Intelligent Manufacturing Workshop