Which brand of sewage online monitor is better?

I seem to have answered you once, so tell me about the brands of online instruments I have seen. Besides what you mentioned, there are Kutcher, WTW, Shimadzu, DKK and Horiba. The following are online monitors for chemical oxygen demand and ammonia nitrogen, which have been verified by National Environmental Monitoring Center, Guangzhou Wen Yi, Beijing Puxi General Instrument Factory and Shanghai Precision Instrument Factory. Some of them have passed through Beijing Puxi General Instrument Co., Ltd., Guangzhou Wen Yi Technology Co., Ltd., Shandong Evergrande Environmental Protection Co., Ltd., Hebei Xianhe Technology Development Co., Ltd., Beijing Maoda Environmental Protection New Technology Co., Ltd., Bluestar Water Treatment Technology Co., Ltd., Beijing Huanke Environmental Technology Co., Ltd., Beijing Yuhuan Hongye Technology Development Co., Ltd., Beijing Zhonghuanfa Environmental Technology Group, Nanjing Linde Environmental Protection Instrument Co., Ltd., Jiangsu Luye Environmental Protection Technology Instrument Co., Ltd. Lanzhou Lianhua Environmental Protection Technology Co., Ltd., Hunan Zhicheng Technology Development Co., Ltd., Wuhan Taiken Environmental Protection Technology Development Co., Ltd., Hubei Intercontinental Environmental Protection Engineering Technology Co., Ltd., Hebei Yatai Environmental Technology Development Co., Ltd., Sichuan Huitong Technology Industry Co., Ltd., Nanjing Huadu Environmental Protection Equipment Co., Ltd., Shimadzu (Hong Kong) Co., Ltd., Shengli Oilfield Longfa Industry and Trade Co., Ltd., Shijiazhuang Gaode Environmental Technology Co., Ltd., Jiangsu Jiangfen Power Analysis Instrument Co., Ltd.,