testo 6651 – moisture transmitter for sensitive environments

Moisture transmitter with Testo's highly accurate and long-term stable moisture sensor

  • Robust precision transmitter
  • -30...120°C
  • 0...100%RH

Leveranstid: 5–10 arbetsdagar

Send a request

Leveranstid: 5–10 arbetsdagar

testo 6651 – transmitter for sensitive environments and cleanrooms

The testo 6651 is placed in the medium-high performance range. It is designed for the monitoring and control of sensitive environments in process engineering and for the control of compressed air systems.

Advantages of the testo 6651

  • This new series of transmitters has interchangeable sensors, which are adapted to the application.
  • The P2A adjustment and setting software gives you total control over the instrument.
  • You can scale/calibrate/adjust the output signal on all outputs including the analog output.
  • A further advantage is that the transmitter can be powered via USB.
  • Adjustment or analysis can therefore be carried out without any other wiring – e.g. on the table or in the service workshop.
  • Integrated relays (optional)
  • Display (optional)

Using the optional display and the four buttons on the front, you can easily adjust, commission and analyze the instrument on site without a PC if you don’t have access to one.
Thanks to the new digital plug-in sensors, it is very easy to change sensors without tools. There is also no need to readjust the transmitter as the 6600 series sensors used in the 6651 have a fully digital interface to the transmitter, which is calibrated and adjusted on delivery.

Contact us for prices and more information

Enclosure MaterialPlastic enclosure
Size122 x 162 x 77 mm
Measurement rangeHumidity: 0...100 %RH

Temperature: -30...+150°C
Protection classIP65
Working temperature of instrument housing-40 to +70 °C

Display: 0 to +50 °C

Storage temp-40...+80°C
Display resolution0.1%RH / 0.1°C
Sensor connectionDigital "plug-in" connection
Screw connectionM 16 x 1.5 (2x) with inner diameter 4-8 mm

M 20 x 1.5 (2x) with inner diameter 6-12 mm
Display2-line LCD with clear text (display is optional) and indication of relay status
Analog output:
Accuracy: Current4...20 mA ±0.03 mA (2-wire)

0...20 mA ±0.03 mA (4-wire)

4...20 mA ±0.03 mA (4-wire) for heated sensor
Accuracy: Voltage0 to1 V ±1.5 mV(4-wire)

0 to5 V ±7.5 mV (4-wire)

0 to10 V ±15 mV(4-wire)
Resolution12 bits
Max load2 thread

12 VDC: 100 Ohms

24 VDC: 500 Ohm

30 VDC: 625 Ohms

4-wire 500 Ohm
Galvanic isolationGalvanic isolation on the outputs (2-wire and 4-wire), isolation between the supply and the outputs (4-wire)
Analog output/Temp
UnitsTemperature in C° / F°

Relative humidity %F / %RH

Dew point in °Ctd /°Ftd
Relay output4 pcs up to 256 VAC /3A NC/C/NO (optional)
Digital outputMini Din for Testo P2A software and Testo 400/650 (optional)
Power supply2-wire: 24VDC ±10%

Galvanic isolation on the outputs (2-wire and 4-wire), isolation between the supply and the outputs (4-wire)


4-wire: 20...30VAC/DC, 200mA max current consumption
Measuring mediumAir, Nitrogen, more on request
Weight0.62kg (without sensor)
Broschyr testo 6681
Datablad testo 6651

Skriv din fråga i det här fältet.

Similar products

testo 6681 – moisture transmitter series for sensitive environments

For monitoring and controlling sensitive environments in process engineering contexts

  • -40...180°C
  • 0...100%RH
  • Interchangeable sensors