FREE EXPRESS SHIPPING 1 DAY WITH UPS NEXT DAY AIR We have an special DISCOUNT of 10% this week on all items over 500$ Please make sure to message me with the the promo code thank you ! Hi, we have a special discount this week of 30$ on any items, please message me to have the discount if youre seriously interest of buying it ! I will send the offer and also free express shipping on all items Thank you and have a great weak ! We are ready to accept any reasonable offers to make the bests deal, message me on bonanza THANK YOU FREE EXPRESS SHIPPING ON ALL ITEMS - We are ready to accept any reasonable offers to make the bests deal, message me on bonanza THANK YOU FREE EXPRESS SHIPPING ON ALL ITEMS - Apera Instruments TN400 Portable Turbidity Meter Apera Instruments TN400 Portable Turbidity Meter, Large Colored TFT display with graphic and text guides, Accuracy: 1% or 0.02 NTU, whichever is greater Infrared light source -- ISO7027 compliant Easy and quick calibration TFT Colored Screen (measurement mode, green in calibration) with graphic and text operation guides U.S. EPA certified, non-toxic, easy-to-use polymer standard solutions CE certified and comes with 2-Year Warranty Apera Instruments TN400 Portable Turbidity Meter is built with an infrared light source, using ISO7207 compliant nephelometric method (90), equipped with a large TFT colored screen, designed for reliable turbidity measurements from 0 to 1000 NTU in various applications both in-field and in-lab e.g. environmental monitoring, water treatment, beverage making, etc. The test kit comes with 4 vials of high-molecular polymer turbidity standard solutions (0.02 NTU, 20.0 NTU, 100 NTU, 800 NTU), an EPA approved primary standard for calibration of turbidity sensors that is safe, non-toxic and disposable. It is NIST traceable to particle size/distribution and optical density, and its inherent stability means it does not settle from suspension. The standards have a guaranteed one-year shelf life even if you've opened the bottle and happened not to have recapped it tightly. The convenient submicron polymer suspensions are non-toxic primary calibration standards approved by the US EPA for drinking water analysis for turbidity.