testo 6621 - Commissioning 11
At a glance: testo 6621-A02 (duct)
Top part of housing, display (option,
cannot be retrofitted) for displaying
readings:
1st line Relative humidity (duct 1),
2nd line Temperature (duct 2).
Mini-DIN port, protected by rubber plug.
Probe shaft.
Sensor protection cap.
Cable coupling for feeding cable through.
4 screws (Phillips) for fastening the top
part of the housing.