testo 445 – climate measuring instrument

Order-Number:  05604450

  • Multi-function climate measuring instrument: measure up to 6 measurement parameters at the same time
  • Internal reading memory for up to 3,000 readings
  • Automatic allocation of the duct cross-section to the measuring location (max. 99 measuring locations)
  • Automatic mean value calculation and determination of the volume flow


You can keep a close eye on indoor air quality with the testo 445 climate measuring instrument: the allrounder can measure up to 6 parameters (with the appropriate probe), which can help you make a professional assessment of indoor air quality. The climate measuring instrument therefore supports you in adjusting and checking ventilation and air conditioning systems.


Product Description

Ventilation and air conditioning systems are used more and more frequently to ensure user independent fresh air supply and thermal comfort in buildings. The testo 445 climate measuring instrument helps you check the system is functioning properly and operating efficiently. This is because the measuring instrument can determine all the relevant measurement parameters for you.

testo 445 climate measuring instrument: an overview of the advantages

The testo 445 climate measuring instrument has two inputs for connecting external probes (which can be ordered separately). At Testo, you have a large selection of suitable probes for the testo 445 climate measuring instrument. Depending on which probe you decide on, you can determine the following parameters:

  • Air velocity (in ventilation ducts, at duct outlets and on extractors)
  • Volume flow
  • Temperature
  • Relative air humidity
  • Dew point
  • Absolute humidity
  • Degree of humidity
  • Enthalpy
  • Pressure
  • CO in indoor air

Further practical features of the climate measuring instrument: its internal memory records up to 3,000 readings. The automatic allocation of the duct cross-section is also particularly useful. This means you can save the measurement data so that it is linked to the measuring location (up to 99 measuring locations). The mean value, the last measured value and the min./max. values can be displayed simply by pressing a key.

As optional accessories for the climate measuring instrument, we recommend you get the testo fast printer to print data out directly at the measuring location and the ComSoft software for convenient data analysis on the PC.

Delivery Scope

testo 445 climate measuring instrument, including battery and calibration protocol.

Technical Data

General technical data
Weight 255 g
Dimensions 215 x 68 x 47 mm
Operating temperature 0 to +50 °C
Product-/housing material ABS
Battery type 9V block battery, 6F22
Battery life 45 h
Display type LCD (Liquid Crystal Display)
Display size 4 lines
Data transfer RS232
Memory 3,000 measuring values
Storage temperature -20 to +70 °C
Temperature – NTC
Measuring range -50 to +150 °C
Accuracy ±0.5 % of mv (+100 to +150 °C)

±0.2 °C (-25 to +74.9 °C)

±0.4 °C (-50 to -25.1 °C)

±0.4 °C (+75 to +99.9 °C)

Resolution 0.1 °C (-50 to +150 °C)
Temperature – TC Type K (NiCr-Ni)
Measuring range -200 to +1370 °C
Accuracy ±0.3 °C (-60 to +60 °C)

±(0.2 °C + 0.5 % of mv) (Remaining Range)

Resolution 0.1 °C (-200 to +1370 °C)
Temperature – TC Type J (Fe-CuNi)
Measuring range -200 to +1000 °C
Accuracy ±0.5 °C or ±0.5 % of mv
Resolution 0.1 °C (-200 to +1000 °C)
Humidity – Capacitive
Measuring range 0 to 100 %RH
Accuracy See probe data
Resolution 0.1 %RH (0 t1 +100 %RH)
Velocity – Vane
Measuring range 0 to 60 m/s
Accuracy See probe data
Resolution 0.01 m/s
Ambient CO₂
Measuring range 0 to 10000 ppm

0 to 1 Vol.%

Accuracy ±(100 ppm + 3 % of mv) (5000 to 10000 ppm)

±(500 ppm + 2 % of mv) (1 to 5000 ppm)

Vol %: see probe data

Resolution 1 ppm

0.0001 Vol.%

Velocity -Thermal anemometer
Measuring range 1 to +20 m/s
Accuracy See probe data
Resolution 0.01 m/s (1 to 10 m/s)

0.1 m/s (10.1 to 20 m/s)

Ambient CO
Measuring range 0 to 500 ppm
Accuracy ±5 % of mv (100 to 500 ppm)

±5 ppm (0 to 100 ppm)

Resolution 1 ppm (0 to 500 ppm)
Pressure measurement
Measuring range See pressure probes
Accuracy ±0.001 hPa (Probe 0638 1345)

±0.001 hPa (Probe 0638 1445)

±0.01 hPa (Probe 0638 1545)

±1.0 hPa (Probe 0638 1645)