TESTO 557 - Page 18

6 Using the manifold
18
Measuring
✓ The actions described in the chapter “Preparing for
measurement” have been performed.
1. Apply pressure to the measuring instrument.
2. Read the measuring values.
With zeotropic refrigerants, the evaporation temperature
to/Ev is displayed after the complete evaporation / the
condensation temperature tc/Co is displayed after complete
condensation.
The measured temperature must be assigned to the
superheating or subcooling side (t
oh
<--> t
cu
). Dependent on
this assignment, the display will show t
oh
/T1 resp. Δt
oh
/SH
or t
cu
/T2 resp. Δt
cu
/SC, depending on the selected display.
- Reading and display illumination are flashing.
• The critical pressure of the refrigerant is within 15 psi (1 bar)
of the highest pressure (and temperature) where the
refrigerant can still condense.
• The maximum. permissible pressure of 870 psi (60 bar) is
exceeded.
Key functions
> Press [▲]
or [▼] to change the reading in the display.
Possible display combinations:
Evaporation pressure
Refrigerant evaporation
temperature to/Ev
Condensation pressure
Refrigerant condensation
temperature tc/Co
or (only with inserted temperature sensor)
Evaporation pressure
Measured temperature
t
oh
/T1
Condensation pressure
Measured temperature
t
cu
/T2
or (only with inserted temperature sensor)
Evaporation pressure
Superheating Δt
oh
/SH
Condensation pressure
Subcooling Δt
cu
/SC