testo 550-1 - this model has been discontinued

Order-Nr.  0563 5505

This model has been discontinued. We suggest the replacement product testo 549.

Product Description

This model has been discontinued.



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 / 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 0 bar

General technical data


200 x 113 x 62 mm

Operating temperature

-10 to +50 °C

Battery life

approx. 150h (without illumination)

Pressure media

N; H₂O; CO₂ (sub-critical); CFC; HFC

Refrigerants in instrument

R12; R22; R123; R134a; R290; R401A; R401B; R402A; R402B; R404A; R406A; R407A; R407C; R408A; R409A; R410A; Ra11A; 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


1060 g


Rs  9,010.00
GST and accessories extra
Rs  10,400.00
GST and accessories extra
Rs  17,250.00
GST and accessories extra


Rs  8,286.00
GST and accessories extra

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.

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.