RIKEN Sangyodan purchases Fukoku Machinery Co., Ltd. to manufacture and sell optical gas indicators, photo-elasticity apparatus, and other precision equipment invented and developed at the Tsuji Laboratory of the Institute of Physical and Chemical Research (RIKEN).

Manufacture and sale of optical gas indicators and photo-elasticity apparatus commence following acquisition of patent licenses belonging to Tsuji Laboratory.

Kenichiro Hayashibe becomes the company’s first president (office held from December 1938 until May 1944). Capital of JPY450,000 and workforce of approximately 100 employees.

Company founded; name changed to RIKEN KEIKI Co., Ltd. Thirty koto shogakko (higher elementary school) graduates taken on as technical apprentices.

First sales office opened in Sapporo to expand sales in Hokkaido, where numerous coal mines are located.

Factory commandeered as munitions factory by the Minister of Munitions.

Jiro Tsuji appointed company’s second president (office held from May 1944 until October 1968).

Modern lens factory completed to support military production. Part of the factory relocated to Tokamachi in Niigata Prefecture as a precaution against air raids.

Lens factory at head office destroyed in air raid.
After the end of the war, the gas indicator factory relocated to Tokamachi in Niigata is moved back to Tokyo on the orders of the GHQ Economic and Science Section to support increased coal production.

Reversion to civilian production following approval from GHQ.

Approved by the Ministry of Commerce and Industry as a major important factory for the manufacture of coal mining safety equipment.

Becomes approved gas indicator manufacturer, contributing significantly to improved safety in coal mines.

Large orders received from China lost due to trade ban during Korean War; in Japan demand from coal mines stagnates; compelled to maintain production at a loss when the price of gas indicators (controlled by pricing regulations) is unable to keep abreast of inflation.

Manufacture separated from retail operations; RIKEN SEIKI KOGAKU Co., Ltd. (merged with RIKEN KEIKI in 1952) established as manufacturing company.

Awarded Director’s Award from the Coal Mining Safety Agency for achievements in manufacturing coal mining safety equipment.

Gas indicators pass certification examination of the Agency of Industrial Science and Technology (AIST) Resources Research Institute.

Development and introduction of Type 17 and Type 18 gas indicators.

Development and introduction of combustible gas alarm and detector (catalytic combustion type).

Completion of head office No. 1 building.

Development and introduction of GP-300 catalytic combustion type portable automatic gas alarm.

Development and introduction of OX-1 oxygen monitor based on newly developed galvanic cell type sensor.

Hideo Oshima appointed third president.
(held office from November 1968 until July 1980)

Development and introduction of FP-200 hydrogen sulfide detector.

Nara Factory (in Sakurai, Nara Prefecture) begins operating to expand the manufacturing division.

RIKEN SERVICE Co., Ltd. established to spin off and expand the Service Division (merged with RIKEN KEIKI in 2015). Subsequently established: RIKEN KEIKI HOKKAIDO SERVICE Ltd.

(merged with RIKEN SERVICE in 2010);
RIKEN KEIKI CHUBU SERVICE Co., Ltd., RIKEN KEIKI CHUGOKU SERVICE Co., Ltd., and RIKEN KEIKI KYUSHU SERVICE Co., Ltd. (all three companies merged in 2011 to form RIKEN KEIKI NISHI-NIHON SERVICE Co., Ltd., then merged with RIKEN KEIKI in 2015);

RIKEN KEIKI KANSAI SERVICE Co., Ltd.
(merged with RIKEN KEIKI in 2015).

Nara factory spun off to form RIKEN KEIKI NARA MFG. Co., Ltd.

Development and introduction of Gascon household gas leak alarm. Introduction of Infrared-based devices.

RIKEN KEIKI KYUSHU SALES Co., Ltd. established (renamed RIKEN KEIKI KYUSHU SERVICE Co., Ltd. in 1987).

Completion of head office No. 3 building.

Awarded Ota Award (present-day Technology Award) from The Japan Gas Association for the development of a gas identification device.

GX-1B and GX-110 toxic gas detectors approved as certified products by Nippon Telegraph and Telephone Public Corporation (present-day NTT). Development of GL-100 gas leak detector in collaboration with Tokyo Gas Co., Ltd. and device certification by the Ministry of International Trade and Industry (present-day Ministry of Economy, Trade and Industry).

Development and introduction of portable automatic suction type combustible gas detector (intrinsically safe explosion-proof type).

RIKEN KEIKI KANSAI SERVICE Co., Ltd. established. Development and introduction of DC-3A oil/water boundary surface automatic detector.

Manually pushed gas leak inspection car based on hydrogen flame ionization receives Ota Award (present-day Technology Award) from The Japan Gas Association.

Development and introduction of GX-7 toxic gas detector.

Yoshio Nakajima appointed fourth president
(held office from July 1980 until June 2006)

Development and introduction of ultra-compact personal toxic gas and combustible gas detectors; development and introduction of LP gas alarm for fishing vessels.

Development and introduction of 82 series of personal gas alarms (capable of detecting four different gas types).

Joint development and introduction of AC-1 atmospheric photoelectron spectrometer with RIKEN. Development and introduction of the IF-774 optical interferometric calorimeter.

Development and introduction of RM-570 fixed gas monitor incorporating bar meter. RIKEN KEIKI CHUBU SERVICE Co., Ltd. established. Overseas joint venture launched with capital participation in EPI SYSTEM Co., Ltd. (wholly-owned subsidiary from 2002).

RIKEN KEIKI ESAN MFG. Co., Ltd. established in Esan in Hokkaido (present-day Hakodate City) to expand the manufacturing division (merged with RIKEN KEIKI in 2008 to form the present-day Hakodate Plant).

Awarded 23rd Ichimura Industry Award (Contribution Prize) from the New Technology Development Foundation for the development of the AC-1 atmospheric photoelectron spectrometer.

Development and introduction of FP-250 paper-tape photoelectric photometry high-sensitivity toxic gas monitor.

Head office annex completed. RKI INSTRUMENTS Inc. established in the USA with capital funding (spun off as subsidiary in 2017).

Development and introduction of GX-2000 portable suction-type four-gas detector.

Development and introduction of GX-2001 four-gas detector; development and introduction of FI-21 optical gas concentration meter.

Further shares in EPI SYSTEM Co., Ltd. purchased to make it a wholly-owned subsidiary (present-day RIKEN KEIKI TAIWAN Co., Ltd.).

Development and introduction of Gas Watch series of wristwatch-style monitors.

Takeshi Koido appointed fifth president
(held office from June 2006 until June 2008)

The AC-3 atmospheric photoelectron spectrometer awarded ADY2006 First Prize at Finetech Japan and Manufacturing & Equipment Division Award at Orgatechno 2006.

Tadashi Iwasawa appointed sixth president
(held office from June 2008 until December 2013)

Absorption and merger of RIKEN KEIKI ESAN MFG. Co., Ltd.
Development and introduction of GX-2009 personal gas detector;
development and introduction of GD-70D fixed gas detector

Three companies (RIKEN KEIKI CHUBU SERVICE Co., Ltd., RIKEN KEIKI CHUGOKU SERVICE Co., Ltd., and RIKEN KEIKI KYUSHU SERVICE Co., Ltd.) merged to form RIKEN KEIKI NISHI-NIHON SERVICE Co., Ltd. Development and introduction of AC-5 atmospheric photoelectron spectrometer.

Hisayoshi Kobayashi appointed seventh president
(held office from December 2013 until March 2021)

Development and introduction of CO-FL1 Hantei Meijin carbon monoxide monitor; development and introduction of OHC-800 explosion-proof calorimeter.

Completion of development center in Kasukabe City in Saitama Prefecture; development and production division relocated from head office. RIKEN SERVICE Co., Ltd., RIKEN KEIKI NISHI-NIHON SERVICE Co., Ltd., and RIKEN KEIKI KANSAI SERVICE Co., Ltd. absorbed and merged. Development and introduction of GX-6000 portable gas monitor, capable of detecting six gas types simultaneously; development and introduction of SDWL-1 Series of fixed wireless gas detectors (meets ISA 100.11a wireless communication standards).

Completion of new head office building. Additional shares of RKI Instruments Inc.

purchased to make it a subsidiary. The subsidiary RIKEN KEIKI GmbH established in Germany to expand shares in European market and provide maintenance and servicing. Development and introduction of OX-08 drop-in type portable oxygen monitor.

Development and introduction of the world's smallest and lightest portable gas monitor "GX-3R" as a four-component gas detector.

Development and introduction of a new type of gas detector, "GX-2100", which uses a "diffusion type" detector as a hazardous gas detector for manhole pit work.

Production center was completed on premises of the Development Center (Kasukabe City, Saitama Prefecture) as a production base for gas detectors. Development and introduction of "GW-3" the world's smallest and lightest portable gas monitor.

We developed and released a fixed gas detector "SD-3".

It conforms to various global standards and is recognized as the global product.

We developed and released a multi-gas detector, "GD-84D," for semiconductor manufacturing facilities. It puts four detectors into a single unit.

Junichi Koyano appointed eighth president
(held office from April 2021)

We developed and released an atmospheric photoemission yield spectrometer "AC-2S". It is a successor model of "AC-2" which can measure work functions and ionization potential in air. "AC-2S" is an enhanced version of "AC-2", featuring new functions and significant improvements.

Tetsuya Matsumoto appointed ninth president.
(held office from April 2023 )