TESTO 549 - Page 17

6 Using the product
17
Measuring
1. Pressurize the measuring instrument.
2. Read off readings.
With zeotropic refrigerants, the evaporation temperature
to/Ev is displayed after the complete evaporation/the
condensation temperature tc/Co is displayed after the
complete condensation.
The measured temperature must be assigned to the
superheating or the subcooling side (t
oh
<--> t
cu
).
Depending on this assignment, t
oh
/T1 or ∆t
oh
/SH or
t
cu
/T2 or ∆t
cu
/SC is shown depending on the selected
display.
- Reading and display illumination flash:
• 1 bar before reaching the critical pressure of the refrigerant,
• upon exceeding the max. permissible pressure of 60 bar.
Key functions
> [▲]
or [▼]: Change the reading display.
Possible display combinations:
Evaporation pressure
Refrigerant evaporation
temperature to/Ev
Condensation pressure
Refrigerant condensation
temperature tc/Co
or (only with connected temperature probe)
Evaporation pressure
Measured temperature t
oh
/T1
Condensation pressure
Measured temperature t
cu
/T2
or (only with connected temperature probe)
Evaporation pressure
Superheating ∆t
oh
/SH.
Condensation pressure
Subcooling ∆t
cu
/SC
With two connected NTC probes, ∆t is also shown.
> [Mean/Min/Max]: Record readings, display min./max. readings,
mean values (since switching on).
Tightness test/pressure drop test
Systems can be tested for tightness with the
temperature-compensated tightness test. The system
pressure and the ambient temperature are measured
over a defined period for this. A temperature probe can
be connected that measures the ambient temperature