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    testo 645 - Humidity/temperature measuring instrument

    0560 6450
  1. High-precision humidity measurement up to ± 1% RH
  2. Internal reading memory (3,000 readings)
  3. Convenient data evaluation via optional PC software
  4. Possibility of attaching a really wide range of optional probes thanks to a large accessory portfolio
    5. The testo 645 humidity/temperature measuring instrument automatically indicates the measurement parameters of relative humidity, absolute humidity, dew point, degree of humidity, enthalpy and temperature at the touch of a button.
    The testo 645 high-precision humidity and temperature measuring instrument offers two probe inputs for attaching a comprehensive range of probes:
    • Channel 1: temperature probe, type K/J/S, NTC
    • Channel 2: humidity/temperature probe or Pt 100 temperature probe

    At the touch of a button, the thermohygrometer automatically indicates the measurement parameters of temperature, relative humidity, dew point, pressure dew point, absolute humidity, degree of humidity and enthalpy, along with min., max. and mean values, as well as the last measured value. Convenient evaluation of the measurement data is possible using the optional PC software. Measurement data can also be printed out directly at the measuring location via the optional testo fast printer.

    Areas of application of the testo 645 humidity/temperature measuring instrument

    • Monitoring of temperature and humidity values in production, storage and server rooms, museums, archives, cold stores, containers and display cases
    • Location of mould formation in residential or other buildings 

    testo 645 humidity/temperature measuring instrument, including battery.

    Temperature - Pt100

    Measuring range
    -200 to +800 °C
    Accuracy
    ±0.1 % of mv (200.1 to 800 °C)
    ±0.2 °C (-200 to 200 °C)
    Resolution
    0.1 °C

    Temperature - NTC

    Measuring range
    -50 to +150 °C
    Resolution
    0.1 °C

    Temperature - TC Type K (NiCr-Ni)

    Measuring range
    -200 to +1370 °C
    Accuracy
    ±0.5 % of mv (-200 to -60.1 °C)
    ±0.5 % of mv (+60.1 to +1370 °C)
    ±0.3 °C (-60 to +60 °C)
    Resolution
    0.1 °C

    Accessories: Humidity probes

  5. Accessories: Humidity probes
    Extension cable
    Extension cable
      :
      0409 0063
    • Accessories: Humidity probes
      Connection cable
      Connection cable
        :
        0430 0143
      • Accessories: Humidity probes
        saline solution pot
        testo saline solution pot for checking humidity probes, 33 %RH
          :
          0554 0636

          • Caps for humidity probes

        • Caps for humidity probes
          Edelstahl-Sinterkappe, Ø 21 mm
          Stainless steel sintered cap, Ø 21 mm, can be screwed onto humidity probe
            :
            0554 0640
          • Caps for humidity probes
            Sintered stainless steel filter
              :
              0554 0641
            • Caps for humidity probes
              PTFE sintered filter, Ø 21 mm, for corrosive substances
              PTFE sintered filter, Ø 21 mm, for corrosive substances
                :
                0554 0666
              • Caps for humidity probes
                Metal protection cap
                  :
                  0554 0755
                • Caps for humidity probes
                  Sintered PTFE filter,
                  Sintered PTFE filter, Ø 12 mm, for corrosive media
                    :
                    0554 0756
                  • Caps for humidity probes
                    Wire mesh filter
                      :
                      0554 0757

                      • Humidity probes

                    • Humidity probes
                      No picture available
                      Humidity/temperature probe
                        :
                        0636 9742

                        • Probes

                      • Probes
                        Robust temperature humidity probe high temperature 0628 0021
                        Robust high-temperature/humidity probe – suitable for measurements at high temperatures up to 180 °C
                          :
                          0628 0021
                        • Probes
                          Flexibler, nicht formstabiler Feuchtefühler
                          Flexible humidity probe (does not retain shape) for measurements in inaccessible places
                            :
                            0628 0022
                          • Probes
                            No picture available
                            Thin humidity probe incl. 4 attachable protection caps for ambient air measurements, measurements in exhaust air ducts and equilibrium moisture measurements
                              :
                              0636 2130
                            • Probes
                              Robust humidtiy probe
                              High humidity level probe w/ heated sensor element, no humidity on sensor
                                :
                                0636 2142
                              • Probes
                                Standard-Raumklimafühler bis +70 °C
                                Standard humidity/temperature probe (Ø 21 mm) for fast assessment of the indoor air climate
                                  :
                                  0636 9740
                                • Probes
                                  Drucktaupunktfühler zur Messung in Druckluftsystemen
                                  Standard pressure dewpoint probe for measurements in compressed air systems
                                    :
                                    0636 9840
                                  • Probes
                                    Precision pressure dew point probe
                                    Precision pressure dew point probe with measuring chamber – pressure dew point measuring range: -40 to +50 °C tpd
                                      :
                                      0636 9841

                                      • Pt100 temperature probes

                                    • Pt100 temperature probes
                                      Standard immersion/penetration probe
                                        :
                                        0604 0273
                                      • Pt100 temperature probes
                                        Highly accurate immersion/penetration probe
                                        Highly accurate immersion/penetration probe
                                          :
                                          0628 0015
                                        • Pt100 temperature probes
                                          0628 0016
                                          Flexible precision immersion probe, cable heat-proof up to +265 °C
                                            :
                                            0628 0016

                                            • Type K (NiCr-Ni) probes

                                          • Type K (NiCr-Ni) probes
                                            Plug-in measuring tip, 550mm long, flexible, for high temperatures, outer casing: Inconel 2.4816
                                              :
                                              0600 5793
                                            • Type K (NiCr-Ni) probes
                                              Spare meas. head for pipe wrap probe, TC Type K
                                              Spare measuring head for pipe wrap probes (TC type K) - Measuring range: -60 to +130°C
                                                :
                                                0602 0092
                                              • Type K (NiCr-Ni) probes
                                                Super quick-action immersion/penetration probe for measurements in liquids
                                                  :
                                                  0604 0493
                                                • Type K (NiCr-Ni) probes
                                                  Super quick-action immersion/penetration probe
                                                  Super quick-action immersion/penetration probe for measurements in gases and liquids with a low-mass tip
                                                    :
                                                    0604 9794

                                                    • Additional accessories and Spare parts

                                                  • Additional accessories and Spare parts
                                                    Extension cable
                                                    Extension cable
                                                      :
                                                      0409 0063
                                                    • Additional accessories and Spare parts
                                                      Connection cable
                                                      Connection cable
                                                        :
                                                        0430 0143
                                                      • Additional accessories and Spare parts
                                                        Sintered stainless steel filter
                                                          :
                                                          0554 0641
                                                        • Additional accessories and Spare parts
                                                          Control and adjustment set for Testo humidity probes
                                                          Control and calibration kit for Testo humidity probes
                                                            :
                                                            0554 0660
                                                          • Additional accessories and Spare parts
                                                            Sintered PTFE filter,
                                                            Sintered PTFE filter, Ø 12 mm, for corrosive media
                                                              :
                                                              0554 0756

                                                              • Certificates

                                                            • Certificates
                                                              Calibration certificate
                                                              ISO humidity calibration certificate; with 2 measuring points: 11.3 and 75.3 %RH at +25°C
                                                                :
                                                                0520 0006
                                                              • Certificates
                                                                Calibration certificate
                                                                DAkkS humidity calibration certificate; with 2 measuring points: 11.3 and 75.3 %RH at +25 °C
                                                                  :
                                                                  0520 0206

                                                                  • Printer and accessories

                                                                • Printer and accessories
                                                                  Spare thermal paper
                                                                  Spare thermal paper for printer, permanent
                                                                    :
                                                                    0554 0568
                                                                  • Printer and accessories
                                                                    testo-Schnelldrucker IRDA mit kabelloser Infrarot-Schnittstelle
                                                                    testo fast printer IRDA
                                                                      :
                                                                      0554 0549

                                                                      • Transport and Protection

                                                                    • Transport and Protection
                                                                      Transport case
                                                                      Transport case (plastic) for measuring instrument, probes and accessories
                                                                        :
                                                                        0516 0445