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0560 6351

testo 635-1 - Temperature and Humidity measuring instrument

testo 635-1
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.
  • Versatile Measurements – Supports air humidity, temperature, absolute pressure, and dew point measurements, even in compressed air.
  • Multiple Probe Compatibility – Can connect to two plug-in probes and receive data from up to three radio probes.
  • Advanced Dew Point Analysis – Calculates dew point and dew point distance for humidity control
  • Data Logging & Display – Shows min., max., and mean values for easy analysis.
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.

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

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.

Air probes

Robuster Luftfühler, TE Typ K

: 0602 1793

Robust air temperature probe (TC type K)

Short response time – due to exposed sensor design.

£ 69.00 £ 82.80

Humidity probes

Dünner Feuchtefühler mit abgesetzter Elektronik

: 0636 2135

Thin humidity probe (Ø 4 mm) - for material moisture

Slim, Compact Design – 4 mm diameter probe with remote electronics, ideal for tight or hard-to-reach measuring points.

£ 472.00 £ 566.40
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: 0636 2161

Robust humidity probe

Dual Functionality – Measures both relative humidity and air temperature for versatile environmental monitoring.

£ 635.00 £ 762.00
Streufeldsonde

: 0636 6160

Scatter field probe for fast and damage-free material moistu...

Convenient Cable Length – Includes a 1.2 m probe cable for easy access to tight or hard-to-reach areas.

£ 384.00 £ 460.80
Feuchte-/Temperaturfühler

: 0636 9735

Humidity/temperature probe (Ø 12 mm)

Humidity sensor with long-term stability

£ 415.00 £ 498.00

Radio handles and probe head

Radio handle for plug-in probe heads

: 0554 0189

Radio handle for plug-in probe heads, incl. T/C adapter, app...

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

£ 125.00 £ 150.00
T/C probe head for surface measurement

: 0602 0394

T/C probe head for surface measurement (T/C Type K)

Precise Surface Temperature Measurement – Designed for accurate readings on various surfaces.

£ 74.00 £ 88.80
Compact professional humidity module

: 0636 9736

Compact professional humidity module

Wireless Functionality – Enables wireless humidity and temperature measurements when used with compatible Testo radio handles.

£ 245.00 £ 294.00

Surface probes

Spare meas. head for pipe wrap probe, TC Type K

: 0602 0092

Spare measuring head for pipe wrap probes (TC type K)

Easy Replacement – Quickly swap out old or damaged measuring heads for uninterrupted operation.

£ 55.00 £ 66.00
Fast-reaction paddle surface probe

: 0602 0193

Fast-reaction paddle surface probe (TC type K) - for measurement in places that are difficult to access

Reliable Measurements – Ideal for narrow openings and hard-to-reach areas.

£ 139.00 £ 166.80
Fast-action surface probe with sprung thermocouple strip

: 0602 0393

Fast-action surface probe (TC type K)

Extremely Fast Response Time (3 Seconds) – Thanks to the thermocouple strip, ensuring quick and precise temperature readings.

£ 135.00 £ 162.00
Efficient, waterproof surface probe with small measurement head

: 0602 0693

Surface probe with a small measuring head (TC type K)

Fast Response Time  – Ensures quick and accurate measurements.

£ 120.00 £ 144.00
Fast-action surface probe with sprung thermocouple strip

: 0602 0993

Fast-action, angled surface probe (TC type K)

Fast 3-Second Response Time – Thermocouple strip enables quick and precise measurement.

£ 165.00 £ 198.00
Waterproof surface probe with widened measurement tip

: 0602 1993

Surface probe with widened measuring tip (TC type K)

Extra-wide measuring tip – ideal for accurate readings on flat surfaces.

£ 69.00 £ 82.80

Thermocouples

Thermocouple with TC adapter, flexible, 800 mm long

: 0602 0644

Flexible thermoelectric couple - with TC type K temperature sensor (glass fibre)

With glass fibre coating

£ 20.00 £ 24.00
Thermocouple with TC adapter, flexible, length 1500 mm

: 0602 0645

Flexible thermoelectric couple - with TC type K temperature sensor (glass fibre)

Thermoelectric couple type K with TC plug

£ 30.00 £ 36.00
Thermocouple with TC adapter, flexible, 1500 mm long, PTFE

: 0602 0646

Flexible thermoelectric couple - with TC type K temperature sensor (PTFE)

Thermoelectric couple type K with TC plug

£ 35.00 £ 42.00

immersion/ penetration probes

Efficient and fast-action immersion probe, waterproof

: 0602 0593

Flexible, fast-action immersion probe (TC type K)

Fast Response Time (2 Seconds) – Ensures quick and accurate measurements.

£ 105.00 £ 126.00
Waterproof immersion/penetration probe, TC Type K

: 0602 1293

Waterproof immersion/penetration probe (TC type K)

Fast response time – approx. 7 seconds.

£ 55.00 £ 66.00
Fast-action, waterproof immersion/penetration probe

: 0602 2693

Fast-action immersion/penetration probe (TC type K)

Fast 3-Second Response Time – Thermocouple strip enables quick and precise measurement.

£ 125.00 £ 150.00
Tauch-Messspitze, biegsam, TE Typ K

: 0602 5792

Immersion measuring tip (TC plug type K)

Wiry measuring tip for fast measurement of temperatures

£ 30.00 £ 36.00

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.

Cases

testo 0516 1435 case

: 0516 1435

Service case for measuring instrument, probe and accessories

Tailored Fit – Designed specifically for the testo 435 and compatible probes, including flow velocity and comfort probes.

testo 0516 1035 case

: 0516 1035

Service case for measuring instrument, probe and accessories - such as testo 435, testo 635, and testo 735

Tailored Fit – Custom-designed for Testo measuring instruments such as testo 435, testo 635, and testo 735.

£ 105.00 £ 126.00

Further accessories measuring instrument/probes

Plug-in Power supply

: 0554 0447

Plug-in mains adapter, 5 VDC 500 mA with European adapter, 1...

Reliable Power Supply – Designed for stable and safe power delivery to compatible Testo measuring instruments.

£ 35.00 £ 42.00
External fast charger

: 0554 0610

External fast charger for 1-4 AA rech. batteries, incl. 4 Ni...

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

£ 49.90 £ 59.88
Control and adjustment set for Testo humidity probes

: 0554 0660

Control and calibration kit for Testo humidity probes

Precise Humidity Control & Calibration - Ensures accurate measurement verification at 11.3%RH and 75.3%RH.

£ 330.00 £ 396.00

Printer and accessories

Spare thermal paper

: 0554 0568

Spare thermal paper for printer - 6 Rolls

Universal Compatibility - Works with Testo printers 0554 0622, 0554 0549, and 0572 0576.

£ 32.00 £ 38.40
testo-Schnelldrucker IRDA mit kabelloser Infrarot-Schnittstelle

: 0554 0549

testo fast printer IRDA

Compatibility - Works with testo 327/310 (1st Gen)/330/340/350.

£ 229.00 £ 274.80

Radio handles and probe head for surface measurement

Radio Module for measuring instrument

: 0554 0188

Radio module for measuring instrument, 869.85 MHz, approval ...

For wireless measurements without interfering cables

£ 46.00 £ 55.20

Radio handles, seperate county variant

Radio handle for plug-in probe heads

: 0554 0189

Radio handle for plug-in probe heads, incl. T/C adapter, app...

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

£ 125.00 £ 150.00
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Testo Ltd
Newman Lane
GU34 2URAlton
HampshireUnited Kingdom
01420 544433

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