<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>

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 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.

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.

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/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;

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!

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.

<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="…/p/0563-1625">>> To the product</a></b></div>

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 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.

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.

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

Product-/housing material	paper
Product colour	white

DAkkS humidity calibration certificate - with 2 measuring points

DAkkS humidity calibration certificate - with 2 measuring points

General technical data