<div style="background-color:#dae4ea; border: 1px solid #648798; padding: 10px;"><b>Product no longer available. Have you checked out its successor?<br/>Why not enjoy the benefits that it has to offer:<br/> <a href="…/p/0636-9772">>> To the product (fixed cable)</a><br/> <a href="…/p/0636-9771">>> To the product (wireless, with Bluetooth)</a><br/>Please note that the successor products are only compatible with testo 400 or testo 440.</b></div>

For assessing indoor air quality: use the probe (with the compatible measuring instrument) to measure CO₂ concentration, humidity and air temperature. The readings are transmitted directly to your measuring instrument via Bluetooth, making your measurements particularly convenient.

For assessing indoor air quality: use the probe (with the compatible measuring instrument) to measure CO₂ concentration, humidity and air temperature.

More applications, less equipment: if you already own one of our probes with a universal handle, you can easily expand your portfolio of probes with the CO₂ probe head.

The humidity module can be attached to various Testo radio handles. It enables a high level of accuracy thanks to the precise humidity sensor.<br />
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Wireless handle (0554 0189) and wireless module (0554 0188) are required to use a radio probe, and these can be ordered optionally.

For measurements in cleanrooms and laboratories, and critical processes in the pharmaceutical, industrial and food sectors, as well as in storage, refrigerated and work rooms or in air conditioning/ventilation ducts: use the high-precision humidity/temperature probe (with the compatible measuring instrument) to measure relative humidity and air temperature. The readings are transmitted directly to your measuring instrument via Bluetooth, making your measurements particularly convenient.

For measurements in cleanrooms and laboratories, and critical processes in the pharmaceutical, industrial and food sectors, as well as in storage, refrigerated and work rooms or in air conditioning/ventilation ducts: use the high-precision humidity/temperature probe (with the compatible measuring instrument) to measure relative humidity and air temperature.<br />&nbsp;

More applications, less equipment: if you already own one of our probes with a universal handle, you can easily expand your portfolio of probes with the high-precision humidity/temperature probe head.

For measurements in ventilation ducts: use the hot wire probe (with the compatible measuring instrument) to measure air velocity, volume flow, air temperature and humidity. The readings are transmitted directly to your measuring instrument via Bluetooth, making your measurements particularly convenient.

For measurements in ventilation ducts: use the hot wire probe (with the compatible measuring instrument) to measure air velocity, volume flow, air temperature and humidity.

<div style="background-color:#dae4ea; border: 1px solid #648798; padding: 10px;"><b>Product no longer available. Have you checked out its successor?<br/>Why not enjoy the benefits that it has to offer:<br/> <a href="…/p/0635-1572">>> To the product (fixed cable)</a><br/> <a href="…/p/0635-1571">>> To the product (wireless, with Bluetooth)</a><br/>Please note that the successor products are only compatible with testo 400 or testo 440.</b></div>

More applications, less equipment: if you already own one of our probes with a universal handle, you can easily expand your portfolio of probes with the hot wire probe head.

For measurements in storage, refrigeration and work rooms, in ventilation ducts and also on refrigeration systems and heat pumps: use the humidity/temperature probe (with the compatible measuring instrument) to measure relative humidity and air temperature. The readings are transmitted directly to your measuring instrument via Bluetooth, making your measurements particularly convenient.

For measurements in storage, refrigeration and work rooms, in ventilation ducts and also on refrigeration systems and heat pumps: use the humidity/temperature probe (with the compatible measuring instrument) to measure relative humidity and air temperature.

The ideal probe for measuring the humidity and temperature of the air in storage, refrigerated and work areas, as well as in air conditioning/ventilation ducts. Also suitable for long-term measurements.

More applications, less equipment: if you already own one of our probes with a universal handle, you can easily expand your portfolio of probes with the humidity/temperature probe head.

<div style="background-color:#dae4ea; border: 1px solid #648798; padding: 10px;"><b>Product no longer available. Have you checked out its successor?<br/>Why not enjoy the benefits that it has to offer:<br/> <a href="…/p/0632-1552">>> To the product (fixed cable)</a><br/> <a href="…/p/0632-1551">>> To the product (wireless, with Bluetooth)</a><br/>Please note that the successor products are only compatible with testo 400 or testo 440.</b></div>

<div style="background-color:#dae4ea; border: 1px solid #648798; padding: 10px;"><b>Product no longer available. Have you checked out its successor?<br/>Why not enjoy the benefits that it has to offer:<br/> <a href="…/p/0636-9775">>> To the product</a><br/> Please note that the successor product is only compatible with testo 400 or testo 440.</b></div>

For measurements in industrial exhaust air, in bulk materials and in climatic test cabinets: use the robust humidity/temperature probe (with the compatible measuring instrument) to measure relative humidity and air temperature up to +180&nbsp;&deg;C.<br />&nbsp;

<div style="background-color:#dae4ea; border: 1px solid #648798; padding: 10px;"><b>Product no longer available. Have you checked out its successor?<br/>Why not enjoy the benefits that it has to offer:<a href="https://www.testo.com/400">>> To the product</a></b></div>

Kit for evaluating the indoor air quality. The testo 440 air velocity and IAQ measuring instrument and the CO<sub>2</sub> probe with Bluetooth<sup>&reg;</sup> including temperature and humidity sensor are all safely stowed away in the case. So you can get down to work straight away!

Kit for carrying out measurements in storage, refrigeration and work rooms, in ventilation ducts and also on refrigeration systems and heat pumps. Keep the testo 440 air velocity and IAQ measuring instrument and the humidity/temperature probe with Bluetooth<sup>&reg;</sup> safely stowed away in the case. So you can get down to work straight away!

Use this practical Indoor Comfort ComboKit to handle all relevant measurements in order to evaluate the indoor air quality in indoor areas and to determine the draught risk and degree of turbulence in workplaces. The testo 440 air velocity and IAQ measuring instrument, the CO<sub>2</sub> probe with Bluetooth<sup>&reg;</sup> including temperature and humidity sensor and the turbulence probe are all safely stowed away in the case. So you can get down to work straight away!

Carry out measurements without any annoying cables: use the kit to handle all relevant measurements in ventilation ducts and at air/ceiling outlets. You will receive the testo 440 dP air velocity and IAQ measuring instrument including differential pressure sensor and the 100 mm vane probe head and hot wire probe head (Ø 9 mm) for attachment to the universal Bluetooth<sup>&reg;</sup> handle supplied.  To make measurements more convenient, both probe heads can be combined with the telescope included in the kit. The equipment can be transported safely and conveniently in the robust case.

Carry out measurements without any annoying cables: use the kit to handle all relevant measurements in ventilation ducts and at air/ceiling outlets. You will receive the testo 440 dP air velocity and IAQ measuring instrument including differential pressure sensor, two vane probe heads (Ø 100 mm and Ø 16 mm) and a humidity/temperature probe head – all three can be attached to the universal Bluetooth<sup>&reg;</sup> handle supplied. To make measurements more convenient, both vane probe heads can be combined with the telescope included in the kit. The equipment can be transported safely and conveniently in the robust case.

The testo 605-H1 thermohygrometer enables reliable measurement of humidity and air temperature and calculation of the dew point. It has a permanently mounted probe shaft which means it is excellent when it comes to carrying out check measurements in ventilation ducts.

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The testo 635-1 temperature and humidity measuring instrument enables you to measure the temperature, air humidity and dew point – in compressed air as well. State-of-the-art technology and a large selection of probes, which are available as an option, enable this wide variety of measuring possibilities.

The testo 635-2 temperature and moisture meter allows you to carry out temperature and moisture measurements on a variety of different materials, surfaces and environments. This is made possible due to leading-edge technology and a wide selection of optionally available sensors.

The U-value is the most important value for proving the heat loss of a building. With the testo 635-2 thermohygrometer and compatible accessories from the U-value set, determining the U-value is now easier than ever.

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.

Ideal kit for IAQ professionals, with a focus on indoor air quality and comfort level. You will receive the testo 400 universal IAQ measuring instrument with intuitive measurement menus, one CO₂ probe (with Bluetooth<sup>&reg;</sup> handle), one turbulence probe and one globe thermometer Ø 150 mm (both with fixed cable). Use the measuring tripod to ensure standard-compliant positioning of the probes. In combination with the IAQ data logger, which is available to order separately, long-term measurements up to 2 weeks can be recorded, even without the IAQ measuring instrument.

Ideal kit for IAQ professionals, with a focus on air flow measurement. You will receive the testo 400 universal IAQ measuring instrument with intuitive measurement menus, one vane probe head (Ø 16 mm), one vane probe head (Ø 100 mm) and one high-precision humidity/temperature probe head – all three can be attached to the Bluetooth<sup>&reg;</sup> handle supplied. For measurements at ceiling outlets, simply combine the 100 mm vane probe with the telescope (can be extended up to 1.0 m) and the 90° angle.

Ideal kit for IAQ professionals, with a focus on air flow measurement. You will receive the testo 400 universal IAQ measuring instrument with intuitive measurement menus, one hot wire probe head (including temperature and humidity sensor), one vane probe head (Ø 100 mm) and one high-precision humidity/temperature probe head – all three can be attached to the Bluetooth<sup>&reg;</sup> handle supplied. For measurements at ceiling outlets, simply combine the 100 mm vane probe with the telescope (can be extended up to 1.0 m) and the 90° angle.

The compact testo&nbsp;605i temperature and humidity measuring instrument with bendable probe head features professional measuring technology in an intelligent format: it can be used in conjunction with a smartphone/tablet and the testo&nbsp;Smart App to reliably measure air temperature and humidity in rooms and ducts.

With the compact testo 625 thermohygrometer, you can measure air temperature and relative humidity easily, quickly and precisely to assess indoor air quality or ensure optimum conditions in storage rooms. The testo Smart App supports you with useful functions, e.g. configuration, display (also as second screen) and storage as well as documentation of the measured values directly in the App.

For refrigeration engineers: The kit contains two testo&nbsp;549i high-pressure gauges, two testo&nbsp;605i thermohygrometers and two testo&nbsp;115i clamp thermometers. Used in conjunction with your smartphone/tablet, the kit is ideal for servicing, troubleshooting and installing air conditioning and refrigeration systems. The testo&nbsp;Smart App makes your work easier and more efficient: over 90 stored refrigerants, automatic calculation of superheating/subcooling, target superheat and cooling/heating power, emailing of measurement data reports as PDF or Excel files.

<div style="background-color:#dae4ea; border: 1px solid #648798; padding: 10px;"><b>Product no longer available. Are you familiar with the alternative?<br/>Why not enjoy the benefits that it has to offer: <a href="…/p/0563-0002-32">>> To the product</a></b></div>

Ultimate kit for all-round engineers in the field of heating, air conditioning, refrigeration and ventilation: The kit contains all the testo Smart Probes and is ideal for carrying out functional checks or for plant maintenance, in conjunction with your smartphone/tablet. The testo Smart App enables you to work more easily and efficiently: Automatically calculate numerous parameters such as superheating/subcooling, target superheat, cooling/heating power or differential temperature. Measurement data reports can be emailed directly as a PDF or Excel file.

For air-conditioning engineers: Compact kit containing four measuring instruments for your most important measuring tasks in, on and involving air conditioning systems. The testo&nbsp;Smart App enables you to work more easily and efficiently: Use intuitive measurement menus for volume flow measurement, for automatic calculation of the dew point and wet bulb temperature or for detecting areas susceptible to mould according to the traffic light principle. Measurement data reports can be emailed directly as a PDF or Excel file.

Early identification of mould risk: Used in conjunction with your smartphone/tablet, the testo&nbsp;Smart Probes mould kit is ideal for detecting areas susceptible to mould at an early stage. Use the testo&nbsp;Smart Probes testo&nbsp;605i and testo&nbsp;805i to measure ambient temperature, relative humidity and surface temperature. Thanks to the testo&nbsp;Smart App, you can work more easily and efficiently: Evaluate the results of the mould indication according to the traffic light principle (green, yellow, red), save measurement data as a PDF or Excel file at the touch of a button. Measurement data reports can be emailed directly - these contain photos of the affected areas for better illustration.

This ISO calibration certificate certifies that your measuring instrument or probe is calibrated. Calibration is carried out according to the ISO standard.

General technical data	Product-/housing material paper
General technical data	Product colour white

ISO humidity calibration certificate - with 2 measuring points

ISO humidity calibration certificate - with 2 measuring points

General technical data

General technical data