{"product_id":"milwaukee-mw401-pro-low-range-total-dissolved-solids-meter","title":"Milwaukee MW401 PRO Low-Range TDS Meter","description":"\u003cp\u003e\u003cspan\u003eThe Milwaukee MW401 PRO is a portable low-range total dissolved solids (TDS) meter designed to measure dissolved-solids levels in water. With a measurement range of 0–1,999 ppm, 1 ppm resolution and automatic temperature compensation, it provides a convenient way to monitor changes in water composition.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eFor aquarium keepers, the MW401 PRO is useful for comparing tap water, reverse osmosis (RO) water and prepared aquarium water, as well as tracking changes in dissolved-solids levels over time.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe meter is supplied with a separate SE510 conductivity probe, a 1-metre cable and calibration solution, making it suitable for aquarium, aquaculture, water conditioning and laboratory applications.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cspan\u003eLow-range TDS measurement\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cspan\u003eThe MW401 PRO measures total dissolved solids from 0 to 1,999 mg\/L (ppm), with a resolution of 1 ppm.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eTDS is an estimate of the concentration of dissolved substances in water. It is calculated from electrical conductivity using a conversion factor.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe MW401 PRO uses a fixed TDS conversion factor of 0.5. This provides consistent readings when monitoring water samples, provided measurements are taken under comparable conditions.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cspan\u003eUseful for aquarium water monitoring\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cspan\u003eTDS measurements can provide useful information about changes in dissolved mineral content in aquarium water.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe MW401 PRO can help aquarium keepers:\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eCompare TDS levels in tap water and reverse osmosis water.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eCheck prepared water before aquarium water changes.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eMonitor changes in dissolved-solids levels over time.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eTrack water consistency in freshwater aquariums.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eCheck water used for fishkeeping and aquaculture.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eMonitor changes in water conditioning and treatment processes.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan\u003eTDS is a supporting water-quality measurement rather than a complete assessment of aquarium water quality. A TDS reading cannot identify individual minerals, nutrients or contaminants, so it should be considered alongside other relevant water tests.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cspan\u003eAutomatic temperature compensation\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cspan\u003eTemperature affects the electrical conductivity of water, which is used to calculate the TDS reading.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe MW401 PRO incorporates automatic temperature compensation (ATC) from 5 to 50°C, helping compensate for temperature-related changes during measurement.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThis supports more consistent readings when testing samples at different temperatures within the instrument's compensation range.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cspan\u003eSeparate SE510 probe with 1-metre cable\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cspan\u003eThe MW401 PRO is supplied with a separate SE510 conductivity\/TDS probe connected to the meter by a 1-metre cable.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThis arrangement allows the probe to be immersed in the water sample while the display remains conveniently positioned outside the container.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe probe is designed for conductivity measurement, from which the instrument calculates the TDS value.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cspan\u003eSimple calibration\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cspan\u003eThe MW401 PRO features manual calibration using the adjustment control on the front of the meter.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eIt is calibrated using a 1382 ppm TDS standard, and a starter calibration solution is supplied with the instrument.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eFor consistent results, recalibrate regularly and whenever the probe or battery is changed. Use fresh calibration solution and follow the manufacturer's instructions.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3\u003e\u003cspan\u003ePortable design and straightforward operation\u003c\/span\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cspan\u003eThe MW401 PRO is designed for practical water testing in the laboratory, aquarium room, water-treatment environment or field.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eFeatures include:\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eLarge, easy-to-read digital display.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003ePortable handheld meter.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eSeparate probe with 1-metre cable.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eAutomatic temperature compensation.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eManual calibration adjustment.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eApproximately 300 hours of battery operation.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003e9V battery supplied.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cspan\u003eTechnical specifications\u003c\/span\u003e\u003c\/h3\u003e\n\u003ctable\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth\u003e\u003cspan\u003eSpecification\u003c\/span\u003e\u003c\/th\u003e\n\u003cth\u003e\u003cspan\u003eMilwaukee MW401 PRO\u003c\/span\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eMeasurement parameter\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eTotal dissolved solids (TDS)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eTDS range\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e0–1,999 mg\/L (ppm)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eTDS resolution\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1 mg\/L (ppm)\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eAccuracy at 25°C\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e±2% of full scale\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eTDS conversion factor\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e0.5\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eTemperature compensation\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eAutomatic\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eCompensation range\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e5–50°C\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eProbe\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eMilwaukee SE510 conductivity\/TDS probe\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eProbe cable\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1 metre\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eCalibration\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eManual\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eCalibration standard\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1382 ppm\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eOperating environment\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e0–50°C\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eMaximum relative humidity\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e95%\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eBattery\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e1 × 9V alkaline\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eApproximate battery life\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e300 hours\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eMeter dimensions\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e143 × 80 × 32 mm\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cspan\u003eMeter weight\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eApproximately 220 g including battery\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003e\u003cspan\u003eSupplied with\u003c\/span\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eMilwaukee MW401 PRO TDS meter.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eSE510 conductivity\/TDS probe.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003e1-metre probe cable.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003e1382 ppm calibration solution sachet.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eCalibration adjustment screwdriver.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003e9V alkaline battery.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eInstructions.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cspan\u003eRecommended accessories\u003c\/span\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eMilwaukee M10032B calibration solution\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e – 1382 ppm TDS calibration solution supplied in individual 20 ml sachets.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cspan\u003eMilwaukee MA9062 calibration solution\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e – 1382 ppm TDS calibration solution in a 230 ml bottle.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan\u003eThe Milwaukee MW401 PRO is a practical choice for aquarium keepers, aquaculture operators and water-quality professionals who need a portable low-range TDS meter with automatic temperature compensation and a separate measuring probe.\u003c\/span\u003e\u003c\/p\u003e","brand":"Milwaukee","offers":[{"title":"Default Title","offer_id":47696734323002,"sku":"MS-MW401","price":138.47,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0247\/9531\/6278\/files\/milwaukee-mw401-pro-low-range-total-dissolved-solids-meter-ms-mw401-2132254.jpg?v=1757078508","url":"https:\/\/groaqua.store\/en-gb\/products\/milwaukee-mw401-pro-low-range-total-dissolved-solids-meter","provider":"GroAqua","version":"1.0","type":"link"}