--- product_id: 2742434 title: "DM-1 In-Line Dual TDS Monitor, 0-9990 ppm Range, +/- 2% Readout Accuracy,Blue & White" brand: "hm digital" price: "€ 44.49" currency: EUR in_stock: true category: "Hm Digital" url: https://www.desertcart.hr/products/2742434-dm-1-in-line-dual-tds-monitor-0-9990-ppm store_origin: HR region: Croatia --- # +/- 2% readout accuracy 0-9990 ppm TDS range Dual in-line sensors for real-time comparison DM-1 In-Line Dual TDS Monitor, 0-9990 ppm Range, +/- 2% Readout Accuracy,Blue & White **Brand:** hm digital **Price:** € 44.49 **Availability:** ✅ In Stock ## Summary > 💧 Know your water, own your wellness. ## Quick Answers - **What is this?** DM-1 In-Line Dual TDS Monitor, 0-9990 ppm Range, +/- 2% Readout Accuracy,Blue & White by hm digital - **How much does it cost?** € 44.49 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.hr](https://www.desertcart.hr/products/2742434-dm-1-in-line-dual-tds-monitor-0-9990-ppm) ## 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 - • **Reliable Accuracy:** Advanced microprocessor technology ensures readings within ±2%, so you trust every drop. - • **Effortless Integration:** Includes quick-connect T-fittings and batteries for seamless installation under sinks or coolers. - • **Ultra-Wide Detection Range:** Covers 0 to 9990 ppm, capturing everything from pure to heavily mineralized water. - • **Optimize Filtration Performance:** Monitor your system’s rejection rate in real-time to avoid costly filter failures and maintain peak purity. - • **Precision Water Quality Insight:** Dual sensors measure tap and purified water simultaneously for instant TDS comparison. ## Overview The HM Digital DM-1 In-Line Dual TDS Monitor offers precise, real-time measurement of total dissolved solids in water with dual sensors for feed and product water. Featuring a broad 0-9990 ppm range and ±2% accuracy, it’s designed for easy installation in filtration systems like RO and DI, empowering users to monitor and optimize water purity effortlessly. ## Description Product 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. From the Manufacturer In-Line Dual TDS Monitor. ## Features - plastic - Imported - 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 ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B001EHAZGW | | Best Sellers Rank | #32,144 in Patio, Lawn & Garden ( See Top 100 in Patio, Lawn & Garden ) #63 in Swimming Pool Water Test Kits | | Brand Name | HM Digital | | Customer Reviews | 4.6 4.6 out of 5 stars (2,735) | | Global Trade Identification Number | 00891144000052 | | Included Components | Bag | | Item Dimensions | 1.9 x 0.8 x 3 inches | | Item Weight | 0.1 Pounds | | Manufacturer | HM Digital, Inc. | | Material Type | Plastic | | Model | 716186 | | Part Number | DM-1 | | Set Name | DM-1 In-Line Dual TDS Monitor | | UPC | 733169337600 891144000052 885169394012 885156810310 | | Unit Count | 1.0 Count | ## Product Details - **Brand:** HM Digital - **Item Weight:** 0.1 Pounds - **Item dimensions L x W x H:** 1.9 x 0.8 x 3 inches - **Material:** Plastic - **Number of Items:** 1 ## Images ![DM-1 In-Line Dual TDS Monitor, 0-9990 ppm Range, +/- 2% Readout Accuracy,Blue & White - Image 1](https://m.media-amazon.com/images/I/61BTf3o7vqL.jpg) ## Questions & Answers **Q: what kind of batteries does this use?** A: 303/357 Battery - SR44 - Silver oxide 190 mAhModel 357A **Q: What are the recommended and maximum flow rates? PSI?** A: FROM HM DIGITAL: There are no recommended flow rates, but there is a maximum pressure rating, which is 232 PSI (16 bar) at room temperature (25C/77F). **Q: What fittings are used that come in contact with water? are they nsf certified....usually printed on part if it is.** A: Yes, they are NSF fittings. **Q: Can this be dropped into a DWC 5 gallon bucket and left in there so to measure the ppm's anytime i turn it on (since wire is sitting in the water) ?** A: It should not be fully submerged, only the probe up to the threads should go into liquid. You could probably seal wire end with a conformant coating or silicone though, do NOT get any on probe end. Yes it can be used in a deep water or reservoir, it does need to have some type of consistent flow in the probe area... to give a consistent reading ! ...get it naysayers, please think before you post inaccurate advice. A basic bubbler agitating solution will work. Be sure to locate probe out of direct bubble area , the bubbles will skew results. I've also used these in unagitated tanks , they work...but will only read the general area , obviously. This will give a general, consistent, read for on the fly observations of nutrient solution, but you still need to compare with a true reading for accuracy. TLDR Dont fully trust this as your standard when used for hydro, DO use as a consistent observation guide,check occasionally against a REAL meter/test, and keep it out of bubbles or it'll get wonky readings. ## 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.hr/products/2742434-dm-1-in-line-dual-tds-monitor-0-9990-ppm](https://www.desertcart.hr/products/2742434-dm-1-in-line-dual-tds-monitor-0-9990-ppm) --- *Product available on Desertcart Croatia* *Store origin: HR* *Last updated: 2026-07-11*