Humidity Measuring Instrument – Testo 635-1

Model No: Testo 635-1Part No: 0560 6351

Testo 635-1 for temperature and humidity measurement. Selection of probes allows you to measure temperature, air humidity and dew point.

  1. Connection of 2 plug-in probes and 3 wireless probes
  2. Measurement of temperature, air humidity, material equilibrium moisture, pressure dewpoint, absolute pressure and U-value
  3. Display of dewpoint distance, min., max. and mean values
  4. Illuminated display
  5. Protection class IP 54


The testo 635-1 for temperature and humidity measurement is ideally equipped for checking the air humidity, temperature and dew point in living areas, in production, storage and server areas and in museums and cold stores. It also aids the measurements of the ambient absolute pressure and dew point in compressed air can be quickly and efficiently.

Attachable optional probes are available for recording the following values:

  1. Air humidity
  2. Material moisture
  3. Pressure dew point in compressed air
  4. Air temperature
  5. Surface temperature
  6. Core temperature
  7. U-value
  8. Absolute pressure

The testo 635-1 for temperature and humidity measurement has two probe inputs for plug-in probes with cables. In addition, upto three further temperature or humidity probes can be displayed with the testo 635-1 via radio-controlled data transmission i.e. wireless.

Robust, practical and easy to handle
In addition to readings, the testo 635-1 temperature and humidity measurement instrument also displays min., max. and mean values.
While the pressure dew point probe measures the pressure dew point in compressed air, the humidity probe helps in measuring the dew point and water content of indoor air along with the psychrometric temperature, in addition to air humidity and air temperature.
The measuring instrument also calculates the dew point distance between indoor air and wall surface. The “Applications” tab in testo 635-1, indicates whether a mould in the home has been caused by incorrect use of ventilation or by moisture ingress.
The user-friendly menu guidance, illumination function for reading legibility even in poor visibility and impact resistance due to its solid housing makes testo 635-1 very reliable and easy to use.

Documentation of measurement data with testo 635-1 temperature and humidity measuring instrument
The optional testo fast printer enables you to print out measurement data such as air humidity or temperature easily at any time.
The practical cyclical printing function on the testo 635-1 not only enables the printout of individual readings, but also of whole series of measurements on the testo fast printer at freely adjustable intervals (for example once a minute).

Technical Data

Temperature – NTC
Measuring range -40 to +150 °C
Accuracy ±0.2 °C (-25 to +74.9 °C) ±0.4 °C (-40 to -25.1 °C) ±0.4 °C (+75 to +99.9 °C) ±0.5 % of mv (Remaining Range)
Resolution 0.1 °C
Temperature – TC Type K (NiCr-Ni)
Measuring range -200 to +1370 °C
Accuracy ±0.3 °C (-60 to +60 °C) ±(0.2 °C + 0.3 % of mv) (Remaining Range)
Resolution 0.1 °C
Humidity – Capacitive
Measuring range 0 to +100 %RH
Accuracy See probes
Resolution 0.1 %RH
Absolute Pressure
Measuring range 0 to 2000 hPa
Accuracy See probes
Resolution 0.1 hPa
General technical data
Operating temperature -20 to +50 °C
Battery type Alkali manganese, mignon, type AA
Storage temperature -30 to +70 °C


Humidity/temperature probe. Part No : 0636 9735 , Measuring range : 0 to +100 %RH, -20 to +70 °C, Accuracy : ±2 %RH (+2 to +98 %RH), ±0.3 °C



 Datasheet Download
 Instruction Manual Download

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