mr. xuming wu, the founder of shanghai san-xin instrumentation inc. was a young teacher in shanghai electromechanical workers university. he decided to leave the university and joined shanghai jing ben biochemical instrument factory. he involved in development, design and manufacture of the first model 301 portable ph meter and ph combination electrode and began his dream trip for electrochemical meters.
in february 1991：
mr. xuming wu joined shanghai san-xin telecom factory, set up ph meter production department, producing and selling portable ph meters of phb series. factory address: no. 65 middle fujian road. area: 15m2, staff: 4 people.
in march 1993：
mr. xuming wu founded shanghai san-xin instrumentation inc., producing and selling ph meter and ph combination electrode. address: no. 266, ningbo road. area: 80m2. staff: 10 people.
in 1994：
shanghai san-xin instrumentation inc. began to produce electrochemical instruments such as portable conductivity meter, benchtop ph meter, sodium ion concentration meter and sold to domestic chinese market.
in march 1994：
mr. xuming wu obtained two patents of ph combination electrode and ion combination electrode.
in 1996：
shanghai san-xin instrumentation inc. began to export many products such as ph electrode, orp electrode, conductivity electrode and ion electrode to the united states, japan, korea, taiwan and other countries and regions. the electrode quality earned praise from customers.
in june 2001：
shanghai san-xin instrumentation inc. moved to no. 293 south yunnan road, shanghai. area: 377m2. staff: 20 people.
in january 2003：
shanghai san-xin instrumentation inc. introduced benchtop ph meter of phs series which used intelligent chip design. this series of meter was the most advanced third-generation electrochemical instrument.
in september 2003：
shanghai san-xin instrumentation inc. compiled "water analysis measurement technology q & a," ranging over 71 issues from theory and technical aspects. this book has been widely circulated and become the first training material in electrochemical instrument industry.
in august 2006：
shanghai san-xin instrumentation inc. moved to 3f, building 4, no. 471 gui ping road, shanghai. area: 1066 m2. staff: 40 people.
in 2007：
shanghai san-xin instrumentation inc. successfully developed benchtop and portable water hardness meter which are by far the unique specialized instrument measuring water hardness by electrode method in the world.
in november 2007：
shanghai san-xin instrumentation inc. attended " the 13th asia control measurement and test equipment exhibition " in singapore. from then on, we attend the overseas exhibition 2 to 4 times each year and we exhibit our products in these most well-known professional exhibitions.
in june 2008：
shanghai san-xin instrumentation. inc. successfully developed mp500 series benchtop electrochemical instrument, which is the most advanced electrochemical instrument of the fourth generation in the world. in this year the product was ce certified.
in august 2008：
shanghai san-xin instrumentation inc. is iso9001: 2000 certified.
in march 2009：
shanghai san-xin instrumentation inc. successfully developed portable electrochemical instrument of sx700 series and pen testers of sx600 series. in this year, the two series of products are ce certified.
in october 2009:：
entrusted by ulab ukraine company, the inspectors from ukrainian state inspection service assessed shanghai san-xin instrumentation inc. regard to manufacturing quality of mp500 series of electrochemical instrument. our products are approved and certified. ulab ukraine company purchased large quantity of mp500 series electrochemical instrument.
in november 2009：
shanghai san-xin instrumentation inc. compiled "application and sales of electrochemical instrument". afterwards, we offered training in shanghai and beijing, which had positive and profound impact in this field.
in may 2010：
shanghai san-xin instrumentation inc. successfully developed high-precision k = 10 conductivity electrode which does not require calibration, the measurement accuracy ≤ 5%. the electrode reaches the most advanced level in the world. a well-known company from the united states purchased large quantity of this electrode.
in september 2010：
shanghai san-xin instrumentation inc. successfully developed benchtop and portable acid-alkali concentration meter by electrode method which are the most advanced and unique products.
in november 2010：
shanghai san-xin instrumentation inc. successfully developed benchtop and portable turbidity meter by electrode method which are the most advanced and unique products.