10 Technical data for testo 425
31
Technical data for testo 425
Adjustment conditions for flow probes:
Adjustment in free jet Ø 350 mm, reference pressure 1013 hPa,
based on testo reference Laser Doppler Anemometer (LDA).
Low flow velocities may result in greater measurement uncertainties
during humidity and temperature measurement! The probe should
be switched on outside a duct under the following conditions:
Ambient temperature: 20°C
Flow: approx. 0 m/s.
Collapse the telescope after use and do not constrict with the cable.
Start with the telescopic links closest to the handle.
Feature
Value
Measurement parameters
m/s, fpm
°C, °F
m³/h, cfm, l/s
Accuracy
±(0.03 m/s + 4% of measuring value) (0 to 20
m/s)
±(0.5 m/s + 5% of measuring value) (20.01 to
30 m/s)
±0.5 °C
Resolution
0.01 m/s
0.1 °C
Measuring range
0 to 30 m/s
-20 to +70 °C
Operating temperature
-20 to +50 °C (instrument)
-20 to +70 °C (probe)
Storage temperature
-20 to +50 °C
Operating humidity
0 to 80 %RH
IP class
IP20
Level of contamination
PD2
Max. operating altitude
≤ 2000 m above sea level
Nominal output
2 W @ 4,5 V DC
Battery type
3 x 1.5 V AA battery
(included in the scope of delivery)
Battery life
>35 h
