Testo 552 Digital Vacuum Gauge (Vacuum Meter) – Bluetooth, 0–20,000 Micron, 1 Micron Resolution (0560 5522)

Testo 552 (product code 0560 5522), which measures the absolute pressure in the system with micron precision during evacuation of air conditioning, refrigeration and heat pump systems, is a digital vacuum gauge with Bluetooth. 0–20,000 micron measuring range; below 1,000 microns it reads with 1 micron resolution; it reliably shows whether the system is free of moisture and non-condensable gases. The measurement is monitored wirelessly, reported and sent by e-mail via the Testo Smart App on a phone or tablet.

Micron Precision in Evacuation and Monitoring from Your Phone

Correct evacuation of the system during a new installation or refrigerant change is the step that determines compressor life: moisture and non-condensable gases left inside lead to acid formation and capacity loss. The Pirani sensor of the Testo 552 reliably measures even the lowest pressures; since the device also calculates and displays the evaporation temperature of water at the measured pressure, you can see whether the moisture in the system has really been removed. When the user-defined alarm threshold is reached, the display gives a visual alert; this makes it easy to follow the vacuum value and holding time specified by the manufacturer.

Thanks to the Bluetooth 4.0 interface, the technician does not have to wait next to the vacuum pump: the values are monitored live in the Testo Smart App, and the measurement protocol is sent to the customer by e-mail together with photos and notes. Via its MiniDIN connection, the device can also be connected to the Testo 570 digital manifold. IP42 protection and an impact-resistant body make it suitable for field conditions.

Technical Specifications (Official Testo Data)

• Brand / Model: Testo 552 · product code 0560 5522
• Measuring Range (absolute pressure): 0 … 20,000 microns (0 … 26.66 mbar)
• Accuracy: ±(10 microns + 10% of reading), in the 100 … 1,000 micron range
• Resolution: 1 micron (0–1,000) · 10 microns (1,000–2,000) · 100 microns (2,000–5,000) · 500 microns (5,000–10,000) · 5,000 microns (10,000–20,000)
• Sensor: Pirani absolute pressure sensor
• Overload: absolute 6.0 bar (87 psi) · relative 5.0 bar (72 psi)
• Measuring Units: micron, mbar, hPa, Pa, mmHg, Torr, inHg, inH₂O
• Measuring Rate: 0.5 s
• Connection: 2 × 7/16" UNF (1/4" SAE) · 1 × MiniDIN (Testo 570 connection)
• Interface: Bluetooth® 4.0 · Testo Smart App (iOS 11 / Android 6 or later)
• Display: backlit, with visual alarm threshold
• Power Supply: 2 × AA batteries · battery life 50 hours (with Bluetooth and backlight off)
• Operating / Storage Temperature: −10 … +50 °C / −20 … +50 °C
• Protection Class: IP42
• Dimensions / Weight: 160 × 110 × 50 mm · 500 g
• Color: black / orange

Scope of Delivery

• Testo 552 digital vacuum gauge (with Bluetooth)
• 2 × AA batteries
• Factory test protocol

Technician Tips

• Connect the gauge close to the system, not the pump: at the pump outlet the vacuum gauge shows the pump's own vacuum, while on the system side it shows the actual system pressure; read the target value on the system side.
• Do not skip the standing test: once the target is reached, switch off the pump and watch whether the pressure rises; a fast rise indicates a leak, a slow rise indicates moisture. The 552's evaporation temperature display makes this distinction easier.
• Set the alarm threshold according to the manufacturer: many AC manufacturers require 500 microns or below; enter the threshold in the device and let the visual alarm call you.
• Protect the sensor from oil: if vacuum pump oil gets into the sensor, the measurement drifts; keep the gauge above the pump and upright, and fit its caps after use.
• Leave the report with the customer: the measurement protocol sent from the app serves both as a warranty record and as a reference for the next service.

Technical document: Testo 552 datasheet (PDF, English)