sonde (RS92), approx 220 × 80 × 75 mm (8.7 × 3.1 × 3 in) Vaisala originated in the 1930s when Professor
Vilho Väisälä (1889–1969), Vaisala's founder and long-time managing director, invented some of the operating principles of a
radiosonde. He sent the first Finnish radiosonde aloft in December 1931. After the first sounding, Väisälä continued with further development and tests until a radiosonde could be brought into production and deliveries started in 1936. From the very start, Vaisala was an international business, exporting 95 percent of the production. As the Vaisala radiosonde became internationally renowned, the demand for them increased. In 1944, Prof. Väisälä established a company called
Mittari Oy ("Gauge Incorporated") and set up manufacturing facilities for radiosonde systems. The first sounding system included a semi-automatic radiosonde receiver, a calibration device, and a ground check set. The company employed 13 people at the time. Later, in 1955, the name of Mittari was changed to Vaisala. From a modest start, the company evolved to become a world leader in many measurement fields and to establish a noteworthy Finnish export industry. At the end of 1954, a modern manufacturing plant was relocated in Vantaa. Since then, the headquarters have been expanded several times and Vaisala's product range has been diversified and expanded greatly. Nowadays Vaisala employs over 2,400 people and serves customers in over 150 countries.
Commercial production since 1936 After the first sounding, Väisälä continued with further development and tests until a radiosonde could be brought into commercial production. Radiosonde deliveries started with the
RS11 (1936–). Amongst its first customers was the
Massachusetts Institute of Technology. In 1937, Väisälä's radiosonde won a gold medal at the
World Fair in Paris.
Recovering from the wars World War II, the Finnish Winter War 1939–1940, and the Finnish Continuation War 1941–1944 disrupted many lives and upset business and delivery activities internationally. The post-war decades witnessed a strenuous effort to revive the national and international economies. Vaisala grew to employ 60 people in 1954. The first issue of Vaisala News magazine was published in 1959. Thanks to major product development efforts, during the 1950s and 1960s, the Vaisala Sounding System became completely electronic, the first automatic radiosonde receiver and the world's first fully transistorized radiosonde
RS13 (1965–) were introduced, and the first weather satellite image receiver was delivered. Yrjö Toivola took over as the managing director of the company when Professor Vilho Väisälä died in 1969.
Vigorous 1970s and 80s The 1970s and 1980s were busy decades for Vaisala. Thin-film technology was developed for Vaisala HUMICAP® relative humidity sensors - the first in the world. The Vaisala CORA Automatic Sounding System - along with automatic weather stations, road weather stations and aviation weather systems was introduced. In 1975, Vaisala employed over 200 people. During the 1980s, numerous new offices were established to ensure the company's ability to serve customers worldwide in the UK, Japan, USA, Germany, and Australia. A traffic weather company was also acquired in the UK. Vaisala's first cleanroom was built to enable the design and manufacture of semiconductors in-house. Vaisala BAROCAP® barometric pressure sensor technology was introduced, as well as a new radiosonde family - the Vaisala Radiosonde
RS80 (1981–2008). These units made use of a water-activated wet battery that had a very long storage life and high power density but a limited working life. The Professor Vilho Väisälä Award was established in cooperation with the WMO, to stimulate interest in meteorological research involving meteorological observation methods and instruments. The radiosondes have also been used in many upper air ozone research studies using an attached detector that had the sensor data multiplexed with the standard meteorology dataset. GPS positioning information was added to gain more accurate wind speed information.
New millennium CEO Pekka Ketonen was appointed in 1992. The company was listed on the Helsinki Exchanges in 1994. By then, it employed over 600 people. Further product developments included the introduction of GPS technology for upper air wind measurement, the Vaisala CARBOCAP sensor, and Vaisala DRYCAP sensor technology for industrial dewpoint measurement. New offices were established in France and China, and business acquisitions in aviation weather and surface weather further enhanced Vaisala's presence in the USA. The new millennium was kicked off with yet more business acquisitions - in wind profiling, lightning detection, and aviation weather. U.S. manufacturing operations were concentrated in
Boulder, Colorado. New product launches included a new radiosonde product family - the Vaisala Radiosonde
RS92 (2003 - in production), as well as the Vaisala Weather Transmitter, which measures the six most essential weather parameters in one compact instrument. This was much improved from the previous generation device and now included consumer cells to make up the battery due to energy saving techniques. CEO Ketonen retired on October 1, 2006. Vaisala's board of directors appointed Kjell Forsén the new company CEO. Forsén last served as president of Ericsson Finland before joining Vaisala on September 18, 2006. As of October 2020, Vaisala's President and CEO is Kai Öistämö. Vaisala technology has played a part in space exploration for some 60 years, for instance the
Mars Rover Curiosity,
Mars Rover Perseverance and
Schiaparelli EDM lander contain pressure and humidity sensors manufactured by Vaisala. With new developments in
miniaturization, communications, and sensors a new radiosonde the model
RS41 (2014 – in production) was announced. This model had again made improvements in specifications. Launch preparation made simple with the RI41 ground check device. It is smaller and has pre-flight dry-point humidity sensor calibration achieved by heating the sensor to drive off contaminants. It is also available in a model (RS41-SG) without a pressure sensor, the pressure reading is derived from the GPS altitude, temperature and humidity readings. In September 2022, the Group launched
Vaisala Xweather to provide environmental forecast and observation data services for businesses and developers. ==History of acquisitions and divestments==