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    testo 635-1 - Temperature and Humidity measuring instrument

    Product no. 0560 6351
    testo 635-1
    This meter requires a probe for commissioning.
    Click here for sensor selection.
    £ 390.00with VAT £ 468.00
    1
    FREE Shipping – T’s & C’s apply
    Delivery time: 3 – 5 working days
    +44 1420 358121
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    Your benefits
  1. Versatile Measurements – Supports air humidity, temperature, absolute pressure, and dew point measurements, even in compressed air.
  2. Multiple Probe Compatibility – Can connect to two plug-in probes and receive data from up to three radio probes.
  3. Advanced Dew Point Analysis – Calculates dew point and dew point distance for humidity control
  4. Data Logging & Display – Shows min., max., and mean values for easy analysis.
    5. The testo 635-1 is a professional temperature and humidity measuring instrument designed for precise climate monitoring in various environments. It supports multiple probe types, calculates dew point and absolute pressure, and features wireless measurement data transfer. With robust construction and an intuitive display, it’s perfect for applications in production, storage, HVAC systems, and more.

    Description

    The testo 635-1 Temperature and Humidity Measuring Instrument is a highly versatile device designed for professionals who need reliable climate monitoring in various settings. Whether in production areas, storage facilities, HVAC systems, or museums, the testo 635-1 ensures precise measurements of air humidity, temperature, absolute pressure, and dew point – including in compressed air systems.

    It features two probe inputs for plug-in probes and the ability to receive data from up to three additional radio probes via wireless transmission (up to 20 meters). This allows users to measure multiple parameters simultaneously for comprehensive environmental analysis. The device calculates dew point and dew point distance, helping to prevent condensation and optimise indoor climate conditions.

    Designed for durability and ease of use, the testo 635-1 has an iluminated display for low-light environments, and an intuitive user interface. Users can also benefit from optional real-time data documentation using the testo fast printer, which allows quick printouts of individual readings or entire measurement series at adjustable intervals.

    With its advanced functionality, practical design, and wide range of compatible probes, the testo 635-1 is the ideal solution for professionals in industrial, HVAC, and environmental monitoring applications.

    Delivery Scope

    testo 635-1 temperature and humidity measuring instrument, including calibration protocol and batteries.

    Caution: The instrument can only be commissioned with a probe. These are available separately.

    Technical data

    Temperature - NTC

    Measuring range
    -40 to +150 °C
    Accuracy
    ±0.4 °C (-40 to -25.1 °C)
    ±0.4 °C (+75 to +99.9 °C)
    ±0.5 % of mv (Remaining Range)
    ±0.2 °C (-25 to +74.9 °C)
    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 + 0.5 % of mv) (Remaining Range)
    Resolution
    0.1 °C

    Humidity - Capacitive

    Measuring range
    0 to +100 %RH
    Accuracy
    See probe data
    Resolution
    0.1 %RH

    Sensor

    Air probes

  5. Air probes
    Robuster Luftfühler, TE Typ K
    Robust air temperature probe (TC type K) – measuring range: -60 to +400 °C
      Product no.:
      0602 1793
      £ 65.00with VAT £ 78.00
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      • Humidity probes

    • Humidity probes
      Dünner Feuchtefühler mit abgesetzter Elektronik
      Thin humidity probe (Ø 4 mm) for measuring material moisture via the equilibrium moisture content – can be used in small bore holes and recesses
        Product no.:
        0636 2135
        £ 472.00with VAT £ 566.40
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      • Humidity probes
        Robust humidity probe for measuring the material equilibrium moisture content and humidity measurements at high temperatures
          Product no.:
          0636 2161
          £ 605.00with VAT £ 726.00
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        • Humidity probes
          Streufeldsonde
          Scatter field probe for fast and damage-free material moisture measurement, with probe cable 1.2 m
            Product no.:
            0636 6160
            £ 384.00with VAT £ 460.80
            1

            • Radio handles and probe head

          • Radio handles and probe head
            Radio handle for plug-in probe heads
            Radio handle for plug-in probe heads, approval for the countries: DE, FR, UK, BE, NL, ES, IT, SE, AT, DK, FI, HU, CZ, PL, GR, CH, PT, SI, MT, CY, SK, LU, EE, LT, IE, LV, NO
              Product no.:
              0554 0189
              £ 118.00with VAT £ 141.60
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            • Radio handles and probe head
              T/C probe head for surface measurement
              T/C probe head for surface measurement (T/C Type K)
                Product no.:
                0602 0394
                £ 74.00with VAT £ 88.80
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              • Radio handles and probe head
                Compact professional humidity module
                Compact professional humidity module for wireless humidity/temperature measurement
                  Product no.:
                  0636 9736
                  £ 235.00with VAT £ 282.00
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                  • Surface probes

                • Surface 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
                    Product no.:
                    0602 0092
                    £ 55.00with VAT £ 66.00
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                  • Surface probes
                    Fast-reaction paddle surface probe
                    Fast-reaction paddle surface probe (TC type K) - Measuring range: - 0 to +300°C
                      Product no.:
                      0602 0193
                      £ 132.00with VAT £ 158.40
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                    • Surface probes
                      Fast-action surface probe with sprung thermocouple strip
                      Fast-action surface probe (TC type K) – measuring range -60 to +300 °C, short-term up to +500 °C
                        Product no.:
                        0602 0393
                        £ 129.00with VAT £ 154.80
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                        • Thermocouples

                      • Thermocouples
                        Thermocouple with TC adapter, flexible, 800 mm long
                        Flexible thermoelectric couple (TC type K, glass fibre) – Measuring range: -50 to +400°C
                          Product no.:
                          0602 0644
                          £ 20.00with VAT £ 24.00
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                        • Thermocouples
                          Thermocouple with TC adapter, flexible, length 1500 mm
                          Flexible thermoelectric couple (TC type K, glass fibre) – measuring range -50 to +400°C
                            Product no.:
                            0602 0645
                            £ 30.00with VAT £ 36.00
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                          • Thermocouples
                            Thermocouple with TC adapter, flexible, 1500 mm long, PTFE
                            Flexible thermoelectric couple (TC type K, PTFE) – measuring range -50 to +250°C
                              Product no.:
                              0602 0646
                              £ 31.00with VAT £ 37.20
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                              • immersion/ penetration probes

                            • immersion/ penetration probes
                              Efficient and fast-action immersion probe, waterproof
                              Flexible, fast-action immersion probe (TC type K) – measuring range: -60 to +1000 °C
                                Product no.:
                                0602 0593
                                £ 99.00with VAT £ 118.80
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                              • immersion/ penetration probes
                                Waterproof immersion/penetration probe, TC Type K
                                Waterproof immersion/penetration probe (TC type K) – measuring range -60 to +400 °C
                                  Product no.:
                                  0602 1293
                                  £ 51.00with VAT £ 61.20
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                                • immersion/ penetration probes
                                  Fast-action, waterproof immersion/penetration probe
                                  Fast-action immersion/penetration probe (TC type K) – measuring range: -60 to +800 °C
                                    Product no.:
                                    0602 2693
                                    £ 120.00with VAT £ 144.00
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                                    • Accessories

                                    Cases

                                  • Cases
                                    testo 0516 1435 case
                                    Service case for measuring instrument, probe and accessories, dimensions 518 x 398 x 155 mm
                                      Product no.:
                                      0516 1435
                                    • Cases
                                      testo 0516 1035 case
                                      Service case for measuring instrument, probe and accessories, dimensions 454 x 319 x 135 mm
                                        Product no.:
                                        0516 1035
                                        £ 99.00with VAT £ 118.80
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                                        • Further accessories measuring instrument/probes

                                      • Further accessories measuring instrument/probes
                                        Plug-in Power supply
                                        Plug-in mains adapter, 5 VDC 500 mA with European adapter, 100-250 VAC, 50-60 Hz
                                          Product no.:
                                          0554 0447
                                          £ 34.00with VAT £ 40.80
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                                        • Further accessories measuring instrument/probes
                                          External fast charger
                                          External fast charger for 1-4 AA rech. batteries, incl. 4 Ni-MH rech. batteries with individual cell charging and charge control display, incl. impulse trickle charging, integrated discharge function, with built-in international mains plug, 100-240 V, 300 mA, 50/60 Hz
                                            Product no.:
                                            0554 0610
                                            £ 49.90with VAT £ 59.88
                                          • Further accessories measuring instrument/probes
                                            Control and adjustment set for Testo humidity probes
                                            Control and calibration kit for Testo humidity probes
                                              Product no.:
                                              0554 0660
                                              £ 315.00with VAT £ 378.00
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                                              • Printer and accessories

                                            • Printer and accessories
                                              Spare thermal paper
                                              Spare thermal paper for printer, permanent
                                                Product no.:
                                                0554 0568
                                                £ 30.00with VAT £ 36.00
                                                1
                                              • Printer and accessories
                                                testo-Schnelldrucker IRDA mit kabelloser Infrarot-Schnittstelle
                                                testo fast printer IRDA
                                                  Product no.:
                                                  0554 0549
                                                  £ 219.00with VAT £ 262.80
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                                                  • Radio handles and probe head for surface measurement

                                                • Radio handles and probe head for surface measurement
                                                  Radio Module for measuring instrument
                                                  Radio module for measuring instrument, 869.85 MHz, approval for the countries: DE, FR, UK, BE, NL, ES, IT, SE, AT, DK, FI, HU, CZ, PL, GR, CH, PT, SI, MT, CY, SK, LU, EE, LT, IE, LV, NO
                                                    Product no.:
                                                    0554 0188
                                                    £ 46.00with VAT £ 55.20
                                                    1

                                                    • Radio handles, seperate county variant

                                                  • Radio handles, seperate county variant
                                                    Radio handle for plug-in probe heads
                                                    Radio handle for plug-in probe heads, approval for the countries: DE, FR, UK, BE, NL, ES, IT, SE, AT, DK, FI, HU, CZ, PL, GR, CH, PT, SI, MT, CY, SK, LU, EE, LT, IE, LV, NO
                                                      Product no.:
                                                      0554 0189
                                                      £ 118.00with VAT £ 141.60
                                                      1

                                                      • Applications

                                                      Localising mould

                                                      Damp ceilings and walls may be a result of structural damage. In most cases, however, it is a sign of improper ventilation. Once the mould appears inside a house, the tenant assumes that moisture has come in from outside. Numerous disputes have erupted because of the issue of who is liable for the mould damage. However, it is difficult to find out who or what has caused the mould: the tenant or faulty structural design?

                                                      Testo 635-1 is ideal for measuring moisture in ceilings and walls. Using the optional attachment temperature/moisture probe and optional surface temperature probe, the testo 635 automatically calculates the dew point distance. It provides initial information about whether mould is being caused by condensation, or from moisture ingress due to structural damage or faulty insulation.

                                                      Monitoring production and storage conditions

                                                      Our temperature/humidity measuring instruments are used around the world in production, storage and server rooms, museums, archives, cold storage warehouses, containers and sales counters.

                                                      Manufacturers, carriers, or dealers of sensitive products must ensure that specified temperature or humidity values are observed during production and storage. The testo 635 offers the option of performing spot measurements in relevant places.

                                                      The temperature/humidity measuring instrument testo 635-2 offers the user a wide range of humidity/moisture probes. It provides the option of measuring humidity, material moisture and U-value (for the thermal assessment of structural components). In addition to the standard probes, up to three radio probes can be connected to the device in parallel. Measurement results can be analysed, stored and documented using the supplied PC software.

                                                      Downloads

                                                      Product brochures

                                                      Operating instructions

                                                      Software

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