testo 550-2 Set - this model has been discontinued

Order-Nr.  0563 5506

This model has been discontinued. We suggest these replacement products:


Product Description

Does a sizeable part of the work you do have something to do with refrigerant systems or heat pumps? Then here’s one tool you can’t afford to be without: the testo 550-2 digital manifold gauge.

  • Two temperature compensated pressure sensors measure high and low pressure quickly and reliably and calculate evaporating and condensation temperatures automatically
  • Two temperature connecting points for connectable temperature sensors and simultaneous superheat and subcooling calculation and display
  • Two clamp temperature sensors (in scope of supply) allow you to check the surface temperature safely when clamped directly to the pipe. (See further selection of optional temperature sensors)
  • No need to change refrigerant hoses thanks to automatic heat pump mode
  • 39 most common type refrigerant agents already stored in the meter

Digital manifold gauge: robust and trouble-free. Ideal for use in the field

The testo 550-2 is a robust 2-way metal valve manifold with 3 connecting points and 3 hose clamps. Because it has been built for the field, it can withstand the rough and tumble of everyday use and is especially easy to use. The robust housing protects the testo 550-2 digital manifold gauge against impact and a suspension attachment ensures that the meter is well and safely positioned during measuring. A large, backlit display allows you to read the measurements in the dark or in poor lighting.

Delivery Scope

testo 550-2 digital manifold set, 2 clamp temperature sensors, carry case, calibration protocol, batteries.

Technical Data

General technical data


1060 g


200 x 113 x 62 mm

Operating temperature

-10 to +50 °C

Battery life

approx. 150h (without illumination)

Pressure media

CFC; HFC; N; H₂O; CO₂ (sub-critical)

Refrigerants in instrument

R12; R22; R123; R134a; R290; R401A; R401B; R402A; R402B; R404A; R406A; R407A; R407C; R408A; R409A; R410A; R411A; R413A; R414B; R416A; R417A; R420A; R421A; R421B; R422A; R422B; R422D; R424A; R427A; R434A; R437A; R438A; R502; R503; R507; R600; R600a; R744 (only in the permitted measurement range up to 50 bar); R1234yf; update by Testo Service

Storage temperature

-20 to +60 °C


Measuring range

-50 to +150 °C


±0.5 °C


0.1 °C

Probe connection

2 x Plug-in (NTC)

Pressure measurement

Measuring range

50 bar


±0.75 % fs


0.01 bar t1 0.1 psi

Probe connection

3 x 7/16"-UNF

Overload rel. (low pressure)

60 bar

Overload rel. (high pressure)

60 bar

Low pressure rel.

50 bar

High pressure rel.

50 bar

Vacuum measurement

Measuring range

-1 to 50 bar


Refrigerant flexibility

The 39 most common refrigerants are stored in the instrument as standard. If you cannot find the refrigerant you need, please contact our service department. They will load additional refrigerants on your testo 550 free of charge.

Tightness testing of refrigeration systems

The testo 550 can carry out a temperature-compensated leakage test of the system for rough tightness testing. To do this, the system pressure at the start of the measurement is compared with the one at the end and any difference there may be is displayed directly.

Simultaneous determination of superheating and subcooling

The testo 550 automatically calculates superheating and subcooling of the system using up to 2 temperature probes which can be connected at the same time. This means manual calculations with a separate refrigerant slide are no longer needed.