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HomeService > WTW Quality

Our quality promise

We are doing something about the solution of your tasks in quality assurance: WTW serves a very high quality standard, which you will profit from

WTW quality for 70 years
WTW quality for 70 years

All about WTW products

CE Declarations of Conformity

The CE mark shows the compliance of our products with the respective EU directives.

WTW certifies its products with accredited testing facilities and thus ensures that the conformity assumption is confirmed by independent third parties. Here, you will find detailed information about the meaning and recognition of the CE mark.

IP code (International Protection Code)

An IP code is a type of protection and describes the suitability of electrical equipment for different environmental conditions and at the same time the protection of humans from potential hazards during the use of the operational equipment.

These International Protection Codes indicate the degree of protection against touching, foreign objects and water.

Below you will find a table showing the nomenclature of the ID digits.

1st digit: Protection of the device against entering of solid foreign objects _H 2nd digit: Protection of device against water _H
0 No protection 0 No protection
1 With diameter > 50 mm 1 Vertically entering dripping water
2 With diameter > 12 mm 2 Dripping water, entry angle up to 15° to the vertical
3 With diameter > 2.5 mm 3 Dripping water, entry angle up to 60° to the vertical
4 With diameter > 1.0 mm 4 Spray water from any direction
5 Dust protection* 5 Streaming water from any direction
6 Dust tight 6 Strong streaming water from any direction
* Limited amount of dust may enter under certain appropriate conditions _H 7 intermittent submersion (max. 1m deep, 30 min)
8 Continuous submersion (conditions to be specified separately)
The fulfillment of digits 7 and 8 do not indicate that the digits 5 and 6 for streaming water are met. _H

In the following you will find a few examples for which protection classes have been implemented for WTW products:

The inoLab® benchtop meters have a spray water proof housing: IP 43. The TresCon® analyzers have a spray water proof housing: IP 54. The IQ Sensor Net system components have housings that are protected against strong streaming water from any direction: IP 66. Our portable meters have a waterproof housing: IP 67. Of course, our online sensors have been developed and are protected against continuous submersion: IP 68.


These test certifications indicate the compliance with US and Canadian safety standards.

Here, our certification partners, UL (Underwriter Laboratories) and ITS (Intertek Testing Services) are the state authorized test facilities for the respective country.

Regular ring test participation

Quality-assured analysis of wastewater samples with the WTW total system

WTW regularly participates in ring tests for operation analytics at wastewater treatment plants.

The successful participation is proven by the excellent WTW product line and the AQS of the parameters for the operation analytics of wastewater treatment plants.

EX zone 1

WTW offers products and complete measuring setups that can be used in explosive environments. For example for pH and conductivity measurements. These are suitable for Zone 1 IIB or IIC T6 – zone 1 is an area where a mixture of flammable gases and vapors can be producted during normal operation.

WTW is certified as per the directive 94/9/EG, ATEX 95. This directive describes that electrical and non-electrical devices and systems can be used in explosive environments if the requirements of the "basic health and safety requirements" as well as the conformity evaluation procedures have been fulfilled.


In addition to the legal warranty, WTW offers a warranty period of 3 years for most of its meters, for service contracts, WTW offers up to 5 years. You will find detailed information regarding warranty services for our products in the general technical information of our price lists.

All about the company WTW GmbH

DAkkS-accredited lab

Our lab is DAkkS-certified and we offer you a special service.

You can find our entire product line here: DAkks lab

ISO 9001 certification

The ISO 9001 quality management standard is the nationally and internationally most used and most important standard for quality management. This standard provides the basis for the continuous improvement process of the company internal quality management system.

The ISO 9001 standard stipulates a certain minimum requirement that a company must meet to adhere to the customers' requirements and demands on product quality and service.

ISO 9001 certification

KTA 1401

WTW is approved as per KTA1401 standard, meaning that measuring, analysis and validated data logger systems and their respective services are suitable to be used in power plants.

The certificate is valid for three years and is tested in the course of an audit on site (in Weilheim).

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