Pressure Sensors with outstanding accuracy

KELLER stands for high-accuracy measurement technology. With an accuracy class of 0.05 % FS, the pressure sensors from Winterthur can be used even in the most sensitive applications. But what exactly does that mean?

The term accuracy is not always used consistently, but at least includes the aspects of (non-)linearity, pressure hysteresis and (non-)repeatability. At KELLER, we go one step further and specify the «actual accuracy» including adjustable deviations such as zero point or gain error.

KELLER is not only accurate, but also true. We do not specify typical values in data sheets, but instead guarantee a minimum accuracy and a total error band. Consequently, every product delivered is definitely within the specified accuracy class and does not cause any unpleasant surprises in the application.

Products with a Soul

The seagull is a symbol of freedom. The bird of peace has accompanied KELLER since 1993. Our founder Hannes W. Keller explained its meaning back then as follows: «We are not only concerned with the future of the company. The environment and the survival of mankind are also fundamental ideas of our philosophy. The seagull as a symbol of this will continue to inspire technology and lend weight to our considerations.» First used on a Christmas card, the seagull made it into the company logo, where it still symbolizes KELLER's independence and freedom to this day.

Invented by Hannes W. Keller

Anyone using KELLER pressure sensors relies on the original design and benefits from decades of experience:

In 1966, Hannes W. Keller (also known as HWK) worked at the Honeywell Research Centre in Minneapolis, USA. There, in collaboration with A.R. Zias, he invented the integrated silicon measuring cell, a high-precision measuring element manufactured using semiconductor methods.

The silicon measuring cell was first installed in a process transmitter at Honeywell as early as 1971 and thus introduced to the American market. HWK brought the young invention back to Switzerland and developed the first high-precision static pressure transducers, which have been manufactured at our headquarters in Winterthur since 1974.

On July 25, 1978, HWK's invention was officially patented – United States Patent, 4103273. If you take a close look at the seal of quality, you can find the patent number embedded in the hologram as a microtext.

KELLER Quality

Every day, around 480 employees worldwide put their hearts and souls into precise pressure measurement technology from Winterthur customized to the given application and always in compliance with the KELLER quality guidelines and ISO-9001 certification.

Our extensive measuring and testing expertise is a key success factor. Only few can calibrate and test pressure sensors so accurately and in such volumes. In more than 80 measuring lines, each individual sensor is measured over the entire pressure and temperature range, individually characterized and finally compensated. Each batch of sensor chips undergoes long-term measurements spanning 12 months before it is released for production. New product types are thoroughly tested under various conditions, continuously checked and monitored - e.g. all sensors must withstand 10 million pressure cycles from 0-100% of the total pressure range without faults or signs of fatigue.

Pressure transducers, pressure transmitters, pressure gauges, level probes, data loggers, and customized products are used in a wide variety of applications. Consequently, the requirements that our products must fulfil are very different. This includes standards & regulations such as ATEX, IECEx, UKEX, REACH oder RoHS. The internal calibration certificates for each sensor element and a variety of different measurement protocols are a specialty of KELLER and prove the high quality standard of each final product.

Established 1974

As a young and provocative inventor, Hannes W. Keller started his own company «H.W. Keller dipl. phys. ETH Druck- und Kraftmesstechnik» at St. Gallerstrasse in Winterthur, where the KELLER production is still situated today.

The beginning was not easy and required a lot of perseverance from our founder. In 1977, the first major order of 1,000 OEM PA-10 measuring cells, was the long-awaited breakthrough and the starting signal for a successful establishment in the market. In 1983 it was already possible to find the public limited company «KELLER AG für Druckmesstechnik» and in 1985 the company, which was continuously doing well, expanded internationally with the first foreign branch in Germany. Our corner stone was laid, and KELLER still benefits today from this solid foundation that Hannes W. Keller had laid over 50 years ago for the now 480 employees.

Produced in Switzerland

KELLER has been producing its entire vertical range of manufacture in Winterthur since 1974. You can't get any more «Swiss Made» than that, because a company is allowed to use this designation of origin for as little as 60% of its production in Switzerland. At KELLER, it is not only the production that is in Swiss hands, but also the entire development and design. The pressure measurement technology knowledge gathered over generations worldwide always finds its way back to Winterthur to lay the foundations for the future.

«Swiss Made» is associated worldwide with the values of competence, quality, tradition and being grounded. Values that are very important to KELLER as a company, which are practiced internally and incorporated into the products.

KELLER Pressure technology is manufactured in Switzerland using the latest technology and strives for perfection every day: Our aim is to supply reliable piezoresistive pressure sensors with outstanding precision and long-term stability, which are durable and impress with their functionality.