Shanghai Fangrui Instrument Co., Ltd. is a manufacturer of measuring instruments (with a license for manufacturing measuring instruments such as electronic scales and moisture meters). The main products produced by the company include: digital rotational viscometer, high-precision electronic balance, fully automatic surface tension meter/interface tension meter; Contact angle meter/droplet angle meter, electronic density meter/specific gravity meter; Seven series of laboratory instruments or devices with nearly a hundred specifications, including digital rotational viscometer, constant temperature water bath (oil bath)/low-temperature constant temperature bath/ultra-low temperature constant temperature bath, particle analyzer (settling balance), etc. All kinds of instruments or devices produced by our company are independently developed and produced, and have obtained national inventions (ZL 2014 1 0280162.5) and utility models (ZL 2012 2 0171247.6; ZL 2011 2 0065224.2). Having completely independent intellectual property rights ensures long-term and safe use for users. All instruments produced can be sent for third-party verification by Shanghai Institute of Metrology and Testing Technology, with a one-year warranty and lifetime service.