--- product_id: 48028052 title: "HM Digital DM-1 in-Line Dual TDS Monitor, 0-9990 ppm Range, +/- 2% Readout Accuracy" brand: "hm digital" price: "¥9280" currency: JPY in_stock: true category: "Hm Digital" url: https://www.desertcart.jp/products/48028052-hm-digital-dm-1-in-line-dual-tds-monitor-0 store_origin: JP region: Japan --- # 0-9990 ppm TDS range Auto-off power saving +/- 2% readout accuracy HM Digital DM-1 in-Line Dual TDS Monitor, 0-9990 ppm Range, +/- 2% Readout Accuracy **Brand:** hm digital **Price:** ¥9280 **Availability:** ✅ In Stock ## Summary > 💧 Know your water, own your purity. ## Quick Answers - **What is this?** HM Digital DM-1 in-Line Dual TDS Monitor, 0-9990 ppm Range, +/- 2% Readout Accuracy by hm digital - **How much does it cost?** ¥9280 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/48028052-hm-digital-dm-1-in-line-dual-tds-monitor-0) ## Best For - hm digital enthusiasts ## Why This Product - Trusted hm digital brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Dual Inline Precision:** Simultaneously monitor tap and purified water TDS for real-time filtration insights. - • **Smart Power Management:** Auto-off after 10 minutes conserves battery life, so your monitor is ready when you are. - • **Effortless Installation:** Quick-connect fittings and compact design make setup seamless—get pure water faster. - • **Microprocessor Accuracy:** Advanced tech ensures reliable readings within ±2%, empowering confident water quality decisions. - • **Ultra-Wide Detection Range:** Measures TDS from 0 to 9990 ppm, covering all water qualities with ease. ## Overview The HM Digital DM-1 is a compact, dual inline TDS monitor designed for precise water quality tracking in filtration systems. With a broad 0-9990 ppm range and ±2% accuracy, it provides real-time comparison of tap and purified water TDS levels. Featuring quick installation, advanced microprocessor technology, and an auto-off function for battery conservation, it’s ideal for professionals seeking reliable, on-demand water purity insights. ## Description Product Description: How Pure is Your Water? HM Digital's DM-1 is a dual inline monitor that measures TDS from 0 to 9990 ppm. It includes batteries, two sensors and two 1/4" quick-connect T-fittings. The DM-1 is an easy and convenient method of determining TDS levels for water filtration/purification systems such as reverse osmosis (RO), deionization (DI) and more. It's very useful for coolers or under-the-sink systems. For any type of system that removes TDS, you can install the 'IN' sensor on your tap water (before the system) and the 'OUT' sensor on your product water (after your filtration system) to determine the filter/membrane's effective operating (rejection) rate. ## Features - The DM-1 helps you to measure the tap water coming in vs the purified water going out of your water filtration system at any time - The In-Line Dual TDS Meter displays TDS levels of the feed water and product water with in and out electrode probes - This TDS Monitor is highly efficient and accurate due to its advanced microprocessor technology - Highly efficient and accurate due to its advanced microprocessor technology - Auto-Off function conserves battery power. The unit shuts off automatically after 10 minutes of non-use - Installs quickly and easily ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B001EHAZGW | | Best Sellers Rank | 15,067 in Business, Industry & Science ( See Top 100 in Business, Industry & Science ) 67 in Liquid Analysis Instrumentation 175 in Lab Meters | | Brand | HM Digital | | Country Of Origin | China | | Customer Reviews | 4.7 4.7 out of 5 stars (2,704) | | Global Trade Identification Number | 00891144000052 | | Included Components | Bag | | Item Dimensions | 48 x 20 x 76 millimetres | | Item Weight | 45 g | | Manufacturer | HM Digital, Inc. | | Manufacturer Part Number | DM-1 | | Material | Plastic | | Model Number | 716186 | | Number of Items | 1 | | Set Name | Dual | | UPC | 733169337600 891144000052 885169394012 885156810310 | | Unit Count | 1.0 count | ## Product Details - **Brand:** HM Digital - **Item dimensions L x W x H:** 48 x 20 x 76 millimetres - **Item weight:** 45 g - **Material:** Plastic - **Number of items:** 1 ## Images ![HM Digital DM-1 in-Line Dual TDS Monitor, 0-9990 ppm Range, +/- 2% Readout Accuracy - Image 1](https://m.media-amazon.com/images/I/61BTf3o7vqL.jpg) ![HM Digital DM-1 in-Line Dual TDS Monitor, 0-9990 ppm Range, +/- 2% Readout Accuracy - Image 2](https://m.media-amazon.com/images/I/31WV0Ys762L.jpg) ![HM Digital DM-1 in-Line Dual TDS Monitor, 0-9990 ppm Range, +/- 2% Readout Accuracy - Image 3](https://m.media-amazon.com/images/I/41w6+rfjjNL.jpg) ![HM Digital DM-1 in-Line Dual TDS Monitor, 0-9990 ppm Range, +/- 2% Readout Accuracy - Image 4](https://m.media-amazon.com/images/I/41nJn-BA7ML.jpg) ![HM Digital DM-1 in-Line Dual TDS Monitor, 0-9990 ppm Range, +/- 2% Readout Accuracy - Image 5](https://m.media-amazon.com/images/I/41u44oxSgwL.jpg) ## Available Options This product comes in different **Color** options. ## Questions & Answers **Q: Can i use this in the sump of my aquarium rack, by just mounting the sensors in the water in the sump? ie not inline in an ro/hma system?** A: There are 2 problems. The sensors are calibrated to be used as advised and in open water they will give much higher readings as well as having the uncertainty of their durability. The latter issue is not a short term problem as they are just 2 probes on the end of a pair of wires. It all depends on what you want to achieve. **Q: Tds meter should 2 digit result. should this be 3 digit? e.g 000ppm ??** A: Its a 3 digit readout on an instrument with 2% accuracy. Do not confuse accuracy and precision. Accuracy is how close to the correct result is it? 2% is 2 parts in 100, so some of second digit and all the third digit are wasted. It can determine only 50 TDS steps. Precision is what does it display? The display has 1000 steps, so its very precise. That is 0.1% precision. **Q: I have an RO unit with a post filter to reinstate minerals, should this be installed before the post filter? Or will readings be affected?** A: I have mine after the water comes out of to unit I think if you put post filter all minerals could be filtered out **Q: Trying to recalibrate while disconnected from RO unit but the in and out probes give different readings, why?** A: The probes have to be in the pipe to read. They will not give a “correct” reading if pulled out of and say placed in a cup. You would need to use the T connectors and loop a piece of pipe around ## Frequently Bought Together - HM Digital DM-1 In-Line Dual TDS Monitor, 0-9990 ppm Range, +/- 2% Readout Accuracy,Blue & White - Aquatic Life 4-Stage Reverse Osmosis Deionization Water Filter System RO/DI Filtration Unit with Carbon Plus Cartridge, 100 GPD - 1/4 inch Tube Float Valve Kit for RO Water Reverse Osmosis System water filter Push in to Connect Pipe Hose Tube Fittings CCK tube（ball valve +L+15 feet pipe） (blue) --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.jp/products/48028052-hm-digital-dm-1-in-line-dual-tds-monitor-0](https://www.desertcart.jp/products/48028052-hm-digital-dm-1-in-line-dual-tds-monitor-0) --- *Product available on Desertcart Japan* *Store origin: JP* *Last updated: 2026-09-24*