â·ÃÊͺ¶ÒÁÃÒ¤Ò à¤Ã×èͧÇÑ´¡Ã´´èÒ§ pH Meter EC Meter Conductivity à¤Ã×èͧÇÑ´¡Ã´´èÒ§ à¤Ã×èͧÇÑ´¤ÇÒÁ¹Óä¿¿éÒ à¤Ã×èͧÇÑ´¡Ã´´èÒ§ à¤Ã×èͧÇÑ´µÐ¡Í¹ ¾Õàͪ ÁÔàµÍÃì Waterproof EC500 ExStik II pH/Conductivity/TDS/Salt Me à¤Ã×èͧÇÑ´¡Ã´´èÒ§ ¾Õàͪ ÁÔàµÍÃì Waterproof ExStik II pH/Conductivity/TDS/Salt Meter EC500 à¤Ã×èͧÇÑ´¡Ã´´èÒ§ ÇÑ´¤ÇÒÁ¹Óä¿¿éÒ ÇÑ´ÍسËÀÙÁÔ TDS ã¹à¤Ã×èͧà´ÕÂǡѹ Waterproof ExStik® II pH/Conductivity Meter Combination rugged flat surface pH electrode with autoranging high accuracy Conductivity cell Measures 5 parameters including Conductivity, TDS, Salinity, pH, and Temperature using one electrode 9 units of measure: pH, µS/cm, mS/cm, ppm, ppt, mg/L, g/L, °C, °F Analog bargraph indicates trends Memory stores up to 25 labeled readings Adjustable Conductivity to TDS ratio from 0.4 to 1.0; 0.5 fixed Salinity ratio RENEW feature alerts user when electrode needs replacement Specifications Range Max Resolution Basic Accuracy Conductivity 0 to 199uS/cm, 200 to 1999uS/cm, 2.00 to 19.99mS/cm 0.1uS/cm +/-2%FS TDS/Salinity 0 to 99.9ppm (mg/L), 100-999ppm (mg/L) 0.1ppm (mg/L) +/-2%FS 1.00 to 9.99ppt pH 0.00 to 14.00pH 0.01pH +/-0.01pH Temperature 23 to 194F (-5 to 90C) 0.1F/C +/-1.8F/1C Waterproof IP57 Memory 25 datasets Dimensions 1.4 x 7.3 x 1.6 (36 x 186 x 41mm) " Weight 3.8oz (110g) All in one Conductity EC Meter EC500 Extech pH Meter Salinity Salt Meter TDS Meter Temperature Total Dissolved Solids Water Quality Meter à¤Ã×èͧÇÑ´ TDS à¤Ã×èͧÇÑ´¤ÇÒÁ¹Óä¿¿éÒ à¤Ã×èͧÇÑ´¤ÇÒÁà¤çÁ à¤Ã×èͧÇÑ´¤Ø³ÀÒ¾¹éÓ à¤Ã×èͧÇÑ´¤èҡô-´èÒ§ à¤Ã×èͧÇÑ´¤èÒ¾Õàͪ à¤Ã×èͧÇÑ´µÐ¡Í¹ à¤Ã×èͧÇÑ´ÁÇÅÊÒÃÅÐÅÒÂã¹¹éÓ à¤Ã×èͧÇÑ´ËÅÒ¤èÒ à¤Ã×èͧÇÑ´ÍسËÀÙÁÔ à¤Ã×èͧÇÑ´ä´éËÅÒ¤èÒ áºº»Ò¡¡Ò http://www.ponpe.com/ph-meter/%E0%B9%80%E0%B8%84%E0%B8%A3%E0%B8%B7%E0%B9%88%E0%B8%AD%E0%B8%87%E0%B8%A7%E0%B8%B1%E0%B8%94%E0%B8%81%E0%B8%A3%E0%B8%94%E0%B8%94%E0%B9%88%E0%B8%B2%E0%B8%87-waterproof-exstik-ii-ph-conductivity-tds-salt-temp-meter-ec500-detail.html