â·ÃÊͺ¶ÒÁÃÒ¤Ò Portable tester for measuring of both Free and Total Chlorine up to 3.50ppm CL500 Free and Total Chlorine Meter Features : Large big-digit LCD and splash-proof front panel Measures Free and Total Chlorine up to 3.50ppm with 0.01ppm resolution Advanced optical system uses a narrow band LED lamp that provides accurate and repeatable readings Requires only a 10mL sample size Independent 2-point calibration for Free and Total Chlorine, Auto Power Off Battery operated for field and on-site testing Data Hold and Min/Max record/recall Complete with Free, Total and Zero Chlorine standard solutions, test bottles with covers, Free and Total Chlorine DPD powder (10pcs), cleaning cloth, six AAA batteries, and hard carrying case Specifications: Range (ppm): 0.01 to 3.50ppm Resolution: 0.01ppm Accuracy: ±0.02ppm @ 1ppm Light Source: LED, 525nm Method: Adaptation of USEPA Method 330.5 for waste water and Standard Method 4500-Cl-G for drinking water Response Time: <10 seconds="" li=""> Dimensions: 6.1 x 3.0 x 2.4" (155 x 76 x 62mm) Weight: 11.3oz (320g) Chlorine Meter CL500 Water Quality Meter à¤Ã×èͧÇÑ´¤ÅÍÃÕ¹ à¤Ã×èͧÇÑ´¤Ø³ÀÒ¾¹éÓ