1. Understand Your Application Needs

Different applications require different features. Ask:

Which gases are you monitoring or controlling?

• Combustible (e.g., methane, hydrogen)

• Toxic (e.g., CO, H₂S)

• Oxygen or inert gases

Some controllers are calibrated for specific gases; others support custom calibration.

What are your operating conditions?

• Ambient temperature range

• Humidity

• Dust or corrosive environment

• Explosive atmospheres (ATEX, IECEx rated?)

Controllers designed for harsh or hazardous environments often come with rugged enclosures and special certifications.

2. Accuracy & Sensor Technology

Accurate measurement is foundational:

 Sensor Type

• Electrochemical: Best for toxic gases; accurate, but limited lifespan

• Infrared (NDIR): Good for CO₂ and combustibles; long life

• Catalytic Bead: For combustible gases; robust but needs oxygen

• MOS (Metal Oxide Semiconductor): Lower cost but varying stability

 Look at accuracy specs, response time (T90), and sensor lifetime.

3. Reliability & Quality Standards

Choose controllers built to recognized industrial standards:

Certifications to Check

• CE / UL / CSA

• ATEX / IECEx (for explosive environments)

• ISO 9001 quality control

• SIL (Safety Integrity Level) for safety-critical systems

This ensures manufacturing quality and compliance with safety regulations.

4. Calibration & Maintenance

Reliable systems make it easy to maintain accuracy:

Key Features

• Auto-calibration (periodic, reduces manual work)

• Zero/span calibration access

• Self-diagnostics / sensor health alerts

• Serviceability of sensors

A controller that supports easy calibration and maintenance reduces downtime and operational cost.

5. Integration & Connectivity

Modern controllers should fit into your existing system:

 Interfaces

• Analog 4–20 mA / 0–10 V

• Digital protocols: Modbus RTU/TCP, BACnet, Ethernet/IP

• Relay outputs / alarms

• Cloud connectivity or SCADA compatibility

Ensure the controller communicates with your plant systems and automation stack.

6.Alarms & Safety Features

Good systems don’t just measure—they protect:

✔ Configurable high/low alarm thresholds
✔ Visual/audible alerts
✔ Relay control for ventilation, shut-offs, or safety systems
✔ Fail-safe operation (e.g., output defaults to safe state on failure)

7. Usability & Support

A reliable controller should be easy to use and support:

• Intuitive UI (display, menus)

• Clear documentation

• Training support

• After-sales service and spare parts availability

👉 Local support can drastically reduce downtime.

8. Total Cost of Ownership

Look beyond purchase price:

 Initial cost +
 Sensor replacements +
 Maintenance +
Downtime risk =
True cost

Investing slightly more upfront for quality and reliability often pays off in long-term savings.

9. Example Requirements Checklist

Here’s a quick checklist you can use when comparing quotes:

Tips Before Purchasing

🔹 Compare multiple vendors and models
🔹 Ask for reference installations
🔹 Request demo units or trials
🔹 Verify warranty terms
🔹 Ensure spare sensors are readily available

Phone: 86 185 6630 3837
WhatsApp: 86 185 66303837
Email: ekelairn@gmail.com
Web: http://www.ekgas.com