testo 6621 - Commercial HVAC Temperature/RH Transmitter

Order-Nr.  0555 6621

  • Transmitter with 2 analog outputs (temperature/humidity)

  • High-precision Testo humidity sensor with long-term stability

  • Optional 2-line LCD display

  • P2A software for parameterization, adjustment and analysis

testo 6621 humidity-/temperature transmitter, accuracy ±2.0 %RH, wall or duct version, selectable signal outputs, optional display, external interface for adjustment and setup, 2 analog outputs

**NOTE: Please contact Testo to ensure proper configuration when ordering the testo 6621 Transmitter**


Product Description

The measurement transmitter testo 6621 stands out thanks to its patented humidity sensor which guarantees highest accuracy. Particularly practical: The sensor and the analog outputs can be adjusted, analyzed and parameterized via an external interface using the P2A software.

Select the suitable design according to your application in a room or a duct. The measurement transmitter testo 6621 is available in different product variations: optionally with or without display, in the housing colours grey or white.

Temperature and humidity measurement transmitter testo 6621 - features

  • 2 analog outputs (temperature/humidity), optionally 1 analog output humidity and temperature passive
  • Highly accurate and long-term stable Testo humidity sensor
  • P2A software for parameterization, adjustment and analysis saves time and costs in commissioning
  • Optimum calibration concept by adjustment of the entire signal chain (1-point, 2-point and analog adjustment)
  • 2-line LCD display optional

Delivery Scope

testo 6621 temperature and humidity transmitter as a wall or duct version, with selectable signal outputs, 2-line display (optional), external interface for adjustment and commissioning.


Product Brochures



  • P2A PC software Update-Demo for transmitter  (v1.9, text/x-html, 1 KB) If you already have the P2A PC software installed on your PC, your existing version will be updated. The update is possible with any version of the P2A PC software. However, this version can also be used as a demo version for customers who do not already own the P2A PC software. It expires after 30 days, but can be activated at any time via an activation code.