A Short DIY Guide on How to Change the Testo 340 Flue Gas Analyzer Sensors

✅ Required Tools & Materials:

• Replacement Testo sensors (OEM)
• Phillips screwdriver (if needed for housing screws)
• Anti-static wrist strap (recommended)

🔧 Steps to replace Testo 340 sensors:

1. Turn Off the Device

Shut down the Testo 340 and disconnect it from any power or USB sources.

2. Remove the Rear Cover

• Unscrew and remove the back panel of the analyzer.
• You may need to open the flap or unscrew a panel depending on your model.

3. Locate the Sensors

• The sensors are usually installed in color-coded slots.
• Each sensor has electrical contacts that slot into a matching connector.

4. Remove the Old Sensor(s)

• Carefully pull the sensor straight out (avoid wiggling too much).
• If the sensor has a label, note its type (e.g., O₂, CO, NO, NO₂).

5. Install the New Sensor(s)

• Insert the new sensor into the appropriate slot.
• Ensure the pins are aligned and that it fits snugly.
• Note: Some sensors are plug-and-play, while others may require configuration in the software.

6. Close the Analyzer

• Replace the back cover and screw it in securely.

7. Recalibrate (If Needed)

• After installation, recalibration may be required.
• You can do this via the Testo EasyEmission software or through the device interface.

🔄 Optional: Sensor Configuration

• Navigate to: Menu > Service > Sensor Configuration to view or modify settings.
• Some sensors (like NO₂) may require you to select the type manually after installation.

Here's a short video on how to change the sensor of Testo 340: