Quick answer: The testo 565i participates in system evacuation, but its role must be identified correctly: the 552i is the vacuum sensor, while the 565i is a pump that can use a 552i to control an automated evacuation and hold test.
What makes the testo 565i different
The testo 565i is a smart vacuum pump, not a stand-alone micron gauge. With a connected testo 552i probe it can automate the target-vacuum stop and vacuum-holding test; different pump versions have different displacement capacities.
Prepare and carry out the measurement
- Recover/reclaim refrigerant as required and perform the approved integrity test before evacuation. Refrigeration work is for qualified personnel.
- Connect a suitable evacuation setup and position the micron sensor on the isolated system side—not only at the pump inlet.
- Start the pump or approved automation using the equipment maker’s target, observe pressure fall and log sensor position and elapsed time.
- Isolate the pump as directed; observe absolute-pressure rise over the prescribed period and investigate moisture, trapped volume, leaks or measurement placement before deciding the system is ready.
Model-specific use and interpretation
Identify the pump version, connect suitable evacuation hoses and the 552i on the system side, then set targets only from the equipment manufacturer’s procedure. Review the pump oil level and any isolation valves before starting the automated cycle.
Microns describe absolute pressure. A pump running for a long time can coexist with a misleadingly low reading if the sensor is isolated behind a restriction. A decay slope is an investigation tool, not a leak-vs-moisture diagnosis by itself.
An automatic “complete” status is only as trustworthy as sensor placement and the chosen thresholds; moisture, restriction or leaks may still require investigation.
Worked example (hypothetical)
Hypothetical vacuum trend: 1,200 microns before isolation, 850 microns after additional pumping and 1,450 microns five minutes after isolation. The rise is 600 microns, but the pass/fail decision must use the equipment maker’s test duration, threshold and conditions. For troubleshooting a post-isolation rise, see vacuum rise after pump isolation.
Troubleshooting a poor vacuum trend
- If pressure drops slowly, look first for restrictions, hose conductance, open service valves and pump-oil condition.
- If pressure rises rapidly on isolation, separate suspected connection leakage from moisture/outgassing by following the approved test sequence.
- Do not test a charged circuit with the vacuum pump or vent refrigerant to atmosphere; use certified personnel and lawful recovery procedures.
Automation still depends on a good pressure sensor location
The 565i pump can automatically stop and conduct a holding test when paired as specified with a 552i vacuum probe. Confirm which capacity version you have and use the correct fluid-compatibility and oil instructions, especially around A2L/A3 applications. A blind automation setpoint is not a substitute for a manufacturer-defined vacuum and decay protocol. Check that the micron gauge is on the system side of any isolation valve. For broader probe-pairing guidance, see Testo Smart Probes compatibility.
Interpretation: A holding-test failure should trigger checks for valve closure, oil contamination, hose restrictions, moisture and leakage—not immediate replacement of the pump.
Limits and safety
Follow the exact instrument manual and the equipment manufacturer’s acceptance criteria. The example is not field evidence, a legal limit or a commissioning target. Work on energized electrical equipment, combustion systems, charged refrigerant circuits or hot surfaces requires qualified personnel and the site’s approved protective procedures.