Shanghai CHENZHU's SPE/APL Explosion-Proof Solution Enters Engineering Verification Stage

Shanghai CHENZHU officially announces that its SPE/APL explosion-proof solution has entered the engineering verification stage. With nearly 30 years of accumulation in intrinsically safe technology as the "safety foundation", we open up cooperation to partners across the industry to jointly solve the safety networking challenge of the "last mile" in process industries. On March 26, 2026, the 2nd Council Meeting and Seminar of the 1st Session of the Special Committee on Fully Networked Industrial Measurement and Control Systems of China Instrument Industry Association was held in Beijing. Miao Changxing, Vice Chairman of China Instrument Industry Association, Mei Ke, Vice President of Mechanism Industry Instrumentation Technology and Economy Institute (MITEI), and other leaders attended and delivered speeches. Shanghai Chenzhu, together with more than 80 committee members, representatives of member units and industry experts from all over the country, participated in the meeting to discuss solutions for industry breakthroughs.

The Industrial Site Network Needs to Be Fully Connected

In the core workshops of process industries such as chemical engineering, petroleum and pharmaceuticals, it is imperative to break through the data bottleneck of the "last mile" in explosion-proof zones. The "low-speed road" that used to rely on 4-20mA signals can no longer meet the massive data demands of intelligent applications such as artificial intelligence and digital twins. Full networking and "one network to the end" are the inevitable future. The core challenge at present is: how to build a data highway that is both "high-speed" and "absolutely safe" in flammable and explosive hazardous areas? Ms. Zhou Ting, Vice Chairman and Professor-level Senior Engineer of Shanghai CHENZHU Instrument Co., Ltd., delivered a special report entitled *Deeply Engaged in Intrinsic Safety, Intelligently Connecting APL – Thoughts on Intrinsically Safe APL Technology Research and Ecosystem Co-construction* at the meeting. She pointed out that Ethernet-APL (Advanced Physical Layer) technology and its supporting 2-WISE (Two-Wire Intrinsically Safe Ethernet) standard are the "keys" to opening the door to the future. The report focuses on the core needs of users for "safety, efficiency and ease of use", and shares Chenzhu's phased research and verification achievements in APL technology, aiming to share experience with industry partners and jointly create an engineering implementation path for APL technology.

How to Safely Run High-Speed Ethernet in Explosion-proof Zones?

• Pneumatic Era: No electricity, but low precision and difficult remote transmission.

• Analog Era (4-20mA): Two-wire system for signal + power supply, popularizing intrinsically safe technology and promoting the popularization of DCS.

• Digital Era (HART/Fieldbus): Added equipment status information, but limited bandwidth.

• Intelligent Era (Ethernet-APL): High-speed, long-distance and power-suppliable, with "safety" as the fundamental problem to be solved.

The key to the real implementation of APL lies in the new standard of "2-WISE" – it is the safety track supporting the "high-speed railway" of APL.

Evolution of Automation Instrument Signals Drives the Upgrade of Intrinsically Safe Explosion-proof Technology

1. Pre-1960s (Pneumatic Era)

- Signal characteristics: 0.2~1bar pneumatic signal; single measured value; mechanical instruments

- Milestone of intrinsically safe explosion-proof: Explosion protection relied on flameproof (d) or increased safety (e); the concept of intrinsic safety had not yet been formed

2. 1960s~1980s (Analog Era)

- Signal characteristics: 4-20mA two-wire standard signal (1966, one of the greatest definitions of automation instruments); two-wire system for signal + power supply; China's DDZ-II type (1974)

- Milestone of intrinsically safe explosion-proof: Deep integration of intrinsic safety and standard signals; establishment of IEC 60079-11, the intrinsically safe explosion-proof standard (1976); certification mode: system certification [IS1.0]; two-wire system simplifies wiring and reduces the implementation cost of intrinsic safety

3. 1980s~2010s (Digital Era)

- Signal characteristics: HART (4~20mA + FSK superposition) for auxiliary signal and equipment information (from single information to multiple information including equipment status); Fieldbus (FF, Profibus PA) for multi-measurement values + equipment diagnosis; DCS system

- Milestone of intrinsically safe explosion-proof: Extension of intrinsic safety to digital communication; certification mode: parameter certification [IS2.0]; point-to-point system to multi-load system; formation of FISCO model, supporting multi-load systems; prototype of bus system [IS3.0] (2005)

4. 2010s~Present (Network/Intelligent Era)

- Signal characteristics: Ethernet-APL (10/100M Ethernet + PoDL), an intrinsically safe digital highway for massive data transmission and intelligent analysis; FCS system; adapting to the digital and intelligent AI era

- Milestone of intrinsically safe explosion-proof: 2-WISE standard (IEC 60079-47); equipment interfaces comply with predefined models; certification mode: model certification [IS3.0]; plug-and-play without system matching; supporting multi-load and arbitrary topologies; enabling high-speed Ethernet Adhere to technological innovation to make automation safer.

How Do We Solve the "Last Mile" Safety Challenge?

CHENZHU's Solution: Equipping the APL "Highway" with a Trinity "Security Guard" At present, CHENZHU's SPE/APL explosion-proof solution has entered the engineering verification stage, with its core composed of three modules:

1. APL Field Switch

– The Isolation Guardian for Non-propagation of Faults

- Full-port intrinsically safe isolation: Completely isolate each port at the physical level to ensure that a single fault never spreads and guarantee the stability of the entire network.

- Three-level intelligent diagnosis: Realize rapid positioning from installation indicator lights, field interfaces to remote monitoring, greatly reducing operation and maintenance complexity.

- Supply chain security: 100% localized selection of core chips and key components to ensure independent and controllable supply.

2. APL Surge Protector

– The Lightning Protection Shield Against "Invisible Killers" - High-speed reliability: High bandwidth and low insertion loss, matching the 10Mbps APL communication rate.

- Compliance with safety standards: The intrinsically safe end meets the highest Ex ia protection level and can be safely connected to instruments in hazardous areas of Zone 0/1/2.

- Strong protection: Maximum discharge current up to 20kA, effectively resisting lightning surge impacts.

3. APL Explosion-proof System Integration Solution – The Plug-and-Play "Safety Foundation"

On site, CHENZHU simultaneously displayed the integrated prototype of the SPE/APL explosion-proof solution in the engineering verification stage. It integrates the protection capabilities of APL switches, surge protectors and high-speed communication links into an integrated design, forming a plug-and-play system solution that significantly lowers the threshold for engineering design and implementation.

CHENZHU will continue to join hands with ecological partners to carry out consistency tests, continuously optimize products and solutions, and help industry partners efficiently implement APL technology applications.

Jointly Build a "One Network to the End" Safety Ecosystem

As one of the main drafters of the national standard *GB/Z 3836.37-2025 Explosive atmospheres – Part 37: Equipment protected by the Two-Wire Intrinsically Safe Ethernet concept (2-WISE)*, Chenzhu insists on transforming complex intrinsic safety challenges into safe and compliant solutions for customers. If you are:

- Users looking for a "one network to the end" solution for intelligent factories

- Manufacturers developing a new generation of intelligent instruments and struggling with explosion-proof certification;

- Integrators interested in Ethernet-APL technology and seeking a "safety foundation" for supporting. Welcome to connect with us for in-depth discussions. With the posture of a "safety foundation", CHENZHU is willing to open up core technologies and platforms, share nearly 30 years of experience in intrinsically safe explosion-proof, provide solution empowerment, and stand side by side with all peers committed to promoting industrial networking transformation to overcome challenges and create a safer and smarter industrial future! The breakthrough of technical standards is the "map" to the future. The real challenge lies in the implementation of standards. Bid farewell to information silos. Expert in automation safety technology.

Knowledge Card | Core Concepts in One Article

• Fully Networked Industrial Measurement and Control System: A new type of industrial measurement and control system centered on advanced industrial communication technologies such as single-pair Ethernet and TSN, which will truly realize "one network to the end" in process industries such as petrochemical and oil and gas.

• Ethernet-APL (Advanced Physical Layer): As a new generation of industrial Ethernet physical layer standard based on IEEE 802.3cg-2019 specifications, it features high Ethernet speed (10 Mbps) and intrinsic safety, supports 1000-meter long-distance transmission and two-wire power supply, and completely breaks the application restrictions of traditional Ethernet in hazardous areas.

• 2-WISE: An intrinsically safe electrical installation and system based on the Advanced Physical Layer (APL) with standardized limits for intrinsic safety parameters of each port.