5 Product description
5.1.2.
Overview of testo 420
1 Battery compartment, on rear of the instrument
2 Display
3 Control keys
4 Probe socket Mini-DIN (only for use on the measurement base)
5 Micro-USB port
6 Connection for pressure measurement
Instrument status icons:
Icon
/
Actual
12
Meaning
Battery capacity
Bluetooth
Measuring mode:
/
Pressure measurement, Pitot tube, volume
flow (air pressure from above into the hood /
suction outlet)
Actual volume flow:
The current ambient conditions are used to
calculate the volume flow. The actual
barometric pressure is measured with the
internal sensor. In applications with volume
flow hood, the temperature is measured by
the integrated temperature/humidity sensor,
with Pitot tube measurement the actual
temperature needs to be input manually.