The Testo 552 digital vacuum gauge with Bluetooth is a solid bit of kit for any tech doing evacuation work on AC/R and heat pump systems. It helps ensure you pull a deep, dry vacuum, which is critical for system longevity and performance, especially here in Australia's humid conditions.

Inadequate evacuation is one of the leading causes of early compressor failure in the field — having a reliable micron gauge like the Testo 552 on the truck helps techs do the job properly and avoid costly callbacks. It's built tough for the trade and lets you monitor progress right from your smartphone.

Best For

• HVAC/R technicians
• Refrigeration apprentices
• Service and maintenance teams
• System commissioning and installation

Compatibility

The Testo 552 is designed for evacuating standard air conditioning, refrigeration, and heat pump systems. It connects via two 7/16" UNF fittings, which are common for many vacuum pump and manifold setups. For app control and data logging, it requires a mobile device with iOS 11.0 or newer, or Android 6.0 or newer, and Bluetooth 4.0.

If you're running a different model or have unique fittings, check compatibility and specs before ordering.

Features

• Bluetooth Connectivity: Control and read complete measurements directly via your smartphone using the free Testo Smart app.
• High-Precision Pirani Sensor: Delivers accurate deep vacuum measurements with a resolution down to 1 micron (in the 0 to 1000 micron range).
• Saturation Temperature Calculation: Provides real-time calculations to determine proper micron/temperature levels for effective moisture removal.
• User-Defined Alarm Points: Set custom alarm thresholds to alert you when your target evacuation values are reached.
• Robust & Reliable: Features an IP42 protection class and a sensor that resists contamination, ensuring consistent accuracy without frequent cleaning.
• On-Site Reporting: The Testo Smart app allows for easy creation and emailing of measurement protocols and reports.

Technical Specifications

What's in the Box

• Testo 552 Digital Vacuum Gauge with Bluetooth
• 2 x AA batteries

Using It on the Job

1. Isolate the System: Always ensure the refrigeration or AC system is depressurised and safely isolated before connecting any vacuum gauge.
2. Connect the Gauge: Attach the Testo 552 to your system's service port (or manifold) using appropriate vacuum-rated hoses and adaptors. Double-check connections for tightness to prevent leaks and false readings.
3. Evacuate: Start your vacuum pump and monitor the evacuation process on the gauge's backlit display or via the Testo Smart app. Aim for deep vacuum levels specific to the refrigerant and manufacturer specifications.
4. Monitor Moisture Removal: Utilise the saturation temperature calculation feature to confirm moisture is being removed from the system. Set alarm thresholds to alert you when your target micron level is reached and held.
5. Verify Vacuum Hold: Once the target vacuum is achieved, shut off your vacuum pump and isolate the system from the pump. Monitor the vacuum gauge for any rise in pressure over time, which indicates a leak.
6. Disconnect: When evacuation is complete and verified, safely disconnect the gauge and cap off all service ports securely.

Limitations & Safety Notes

• Any work on refrigerant circuits requires a current ARCtick licence in Australia.
• Always ensure system pressure is safely vented or recovered before connecting a vacuum gauge.
• Only use on systems compatible with the 7/16" UNF connections provided.
• Protect the gauge from extreme impacts and direct water exposure, despite its IP42 rating, to ensure longevity.
• Always refer to the system manufacturer's specifications for target evacuation pressures and hold times.

Tradie Pro Tip

When you're pulling a vacuum, especially on a larger system or after a compressor burnout, always change your vacuum pump oil. Contaminated oil won't let you pull a deep enough vacuum, and it's a quick job that makes a massive difference to your evacuation depth and time.

Pair With

Pair with a robust vacuum pump, high-quality manifold gauges, and a good set of vacuum-rated hoses for a complete evacuation setup. Consider the optional MiniDIN connection cable for integration with a Testo 570 manifold for enhanced data logging capabilities.