CNG Vigilant, catching leaks before they leave the line.

1. Introduction

In the era of cleaner energy and stringent emission standards, Compressed Natural Gas (CNG) has emerged as a sustainable and cost-effective alternative fuel for vehicles. With the widespread adoption of CNG systems in commercial, passenger, and fleet vehicles, ensuring the safety, integrity, and reliability of these high-pressure fuel systems is more critical than ever.

Introducing CNG Vigilant™, the next-generation automated leak testing solution designed and manufactured by Neometrix Group — a trusted name in high-pressure testing, automotive validation systems, and industrial fluid control technologies. Engineered to meet demanding industry expectations, CNG Vigilant combines cutting-edge sensor technologies, temperature compensation algorithms, and intelligent automation to deliver accurate, safe, and cost-effective leak detection.

Whether you are a vehicle OEM, CNG kit manufacturer, R&D facility, or service center, CNG Vigilant is a must-have solution to ensure that every CNG vehicle that leaves your facility is free from leaks, compliant with regulatory requirements, and ready for the road.

2. System overview

CNG Vigilant™ is a microprocessor-controlled, fully automatic leak tester that evaluates the integrity of CNG circuits and components by detecting even the minutest leaks under high-pressure conditions (up to 350 Bar). It is offered in two configurations:

• Vigilant Ver. 0.30: combines Pressure Decay and Differential Pressure methods with a proprietary Temperature Compensation System for cost-effective, high-speed testing.
• Vigilant Ver. 0.34: incorporates Helium Mass Spectrometry for ultra-high sensitivity leak testing — ideal for critical components and high-performance applications.

With built-in gas recycling, remote control operation, user-configurable parameters, and real-time data logging, CNG Vigilant is a holistic leak testing solution tailored for modern industrial and production environments.

3. Key features and technologies

a) Dual leak detection modes

CNG Vigilant is designed to accommodate varying needs for detection sensitivity, production speed, and cost optimization.

Pressure Decay + Differential Pressure (standard in Ver. 0.30): this method monitors pressure drops within a sealed CNG circuit over a preset period. Any deviation from the acceptable limit indicates a leak. It is highly reliable for:

• Full-vehicle CNG circuit testing
• Line-level production verification
• Rapid cycle times in high-throughput environments

Helium Mass Spectrometry (optional in Ver. 0.34): the Helium Mass Spectrometer detects helium molecules escaping from leaks as small as 1 x 10⁻¹⁰ atm cc/sec. Ideal for:

• Precision testing of regulators, valves, injectors
• R&D, certification, and safety compliance
• Sniffer probe or vacuum chamber configurations

b) Precision temperature compensation

High-pressure gas testing introduces errors due to thermal expansion and compression of gases. Even a 1°C shift can create a pressure error of nearly 1 bar in 100 cc volume at 300 bar. Neometrix addresses this challenge with:

• TTLIV Technology (Temperature-Time-Logic-Integrated-Volume)
• Circuit-specific calibration for up to 5 different circuit volumes
• Software-controlled fill rates to isolate pressure drops due to leaks only

This ensures true leak detection without false alarms due to ambient or process temperature fluctuations.

c) Fully automated operation

CNG Vigilant is designed for effortless, intuitive use on the shop floor or lab:

• Plug-and-play interface with remote control (up to 10 meters)
• One-touch test initiation
• Fully customizable testing parameters: pressure, hold time, leak limits, alarms
• Automatic logging and time-stamped reports after each test

This automation not only improves accuracy and repeatability but also reduces human error and operator fatigue.

d) Nitrogen reuse and auto cylinder switching

To improve operational efficiency and reduce costs:

• Vigilant reclaims nitrogen from the test cycle, compresses it, and stores it in a dedicated reservoir for reuse
• Supports up to 4 nitrogen cylinders simultaneously and auto-switches when one is depleted, ensuring zero downtime
• Reduces nitrogen consumption and makes the system highly sustainable for high-volume operations

e) Built-in safety and redundancy

Testing high-pressure systems demands fail-safe operation:

• Stepwise pressurization to detect loose fittings or open circuits early
• Flow control logic to prevent accidental over-pressurization
• Audio-visual alarms on test failure or abnormal flow behavior
• Circuit integrity monitored continuously at each test stage

f) Reporting, analytics, and traceability

CNG Vigilant supports complete digital documentation:

• Test reports are generated automatically after every cycle
• Vehicle-wise data is stored for quality audits and traceability
• Export options allow data to be sent to external PCs or servers
• User comments and annotations can be added per test

Optional printer integration supports on-the-spot hard copy generation for line-side documentation.

4. Applications

CNG Vigilant is versatile and suitable for a wide range of use cases:

• Automotive OEMs: end-of-line leak testing for CNG-powered vehicles; circuit integrity validation in compliance with ARAI, AIS, and global norms.
• Component manufacturers: regulator testing, nozzle and valve integrity tests; cylinder valve inspection using mass spectrometry.
• R&D and validation labs: leak rate benchmarking of new components; temperature-compensated long-duration pressure holding tests.
• Service stations and retrofit centers: quick check of leak tightness in retrofitted systems; leak verification after servicing CNG systems.

5. Technical specifications

6. Why choose Neometrix Group's CNG Vigilant™?

• Engineered in India with deep expertise in pressure systems
• Combines smart automation with scientific accuracy
• Supports sustainability goals via nitrogen reuse and low test cost
• Trusted by R&D labs, manufacturers, and fleet service providers
• Backed by Neometrix's full service, training, and spares support