• 2 way aluminum valve block with 3 x 1/4" SAE connections
  • Built-in magnifying sight glass
  • (2) NTC temperature probe inputs
  • Real-time calculation of superheat and subcooling
  • 31 refrigerant profiles built in for automatic PT caluculations
  • Fast response time
  • Compact design for ease-of-use transport and setup
  • Large, easy-to-read back-lit display
  • Hardened housing that protects the analyzer
  • Vacuum indication (inches Hg)
  • Altitude compensation


The Testo 550 is a high-performance refrigeration system analyzer that accurately performs temperature and pressure measurements in seconds. It automatically calculates superheat and subcooling for 31 different refrigerants quickly and easily. Testo 550 analyzers are simple enough to use right out of the box and rugged enough for daily use by today's demanding HVAC technicians.

The Testo 550 analyzer features a 2-way aluminum valve block with 3 x 1/4" SAE connections, built-in magnifying sight glass, 2 NTC temperature probe inputs, real-time calculation of superheat and subcooling, and 31 refrigerant profiles for PT calculations. The Testo 550 has a fast response time, compact design, and a large, easy-to-read, backlit display.

The Testo 550 can be used to service, maintain and commission all types of air conditioning, refrigeration and heat pump systems including the newest 16 SEER systems. This Testo refrigeration system analyzer can perform timed pressure drop tests as well as standing pressure tests required for properly commissioning AC/R systems.

The Testo 550 ships complete with meter, clamp temperature probe, integrated hanger-hook, built-in hose holders, 4 AA batteries and calibration certificate. The optional kit also includes an additional clamp temperature probe and hard case.

Testo 550 Refrigeration System Analyzer Specifications
Number of refrigerant profiles 31
Pressure measurement range -14.7 to 580 psi
Vacuum indication 0 inHg to 29,92 inHg
Units of measure °F, °C, psi, inHg, bar, kPa, MPa
Resolution pressure 0.1 psi
Accuracy pressure sensor ±0.75% fs (+1 digit)
Pressure media HCFC, HFC, N, H2O
Temperature 2x NTC ports
Temperature accuracy ±1.8°F (+1 digit)
Valve block configuration 2-way valveblock with 3 hose connections
Display illumination Yes
Power supply (4) AA
Battery life Min. 40 h (without illumination)
Ambient operating temperature -14 to 122°F
Measurement cycle time 0.5 seconds


This product can be used in the following applications: