---
product_id: 30178917
title: "SM-1 1-Stage Inline TDS Monitor For Single Water Line"
brand: "hm digital"
price: "฿2820"
currency: THB
in_stock: true
reviews_count: 5
category: "Hm Digital"
url: https://www.desertcart.co.th/products/30178917-sm-1-1-stage-inline-tds-monitor-for-single-water
store_origin: TH
region: Thailand
---

# 0-9990 ppm TDS range Auto-Off battery saver Advanced microprocessor accuracy SM-1 1-Stage Inline TDS Monitor For Single Water Line

**Brand:** hm digital
**Price:** ฿2820
**Availability:** ✅ In Stock

## Summary

> 💧 Stay ahead of water quality—because your health deserves precision.

## Quick Answers

- **What is this?** SM-1 1-Stage Inline TDS Monitor For Single Water Line by hm digital
- **How much does it cost?** ฿2820 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.co.th](https://www.desertcart.co.th/products/30178917-sm-1-1-stage-inline-tds-monitor-for-single-water)

## 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

- • **Seamless Integration:** Quick-connect 1/4" tee fits effortlessly into any standard water line or RO system.
- • **Smart Power Efficiency:** Auto-off feature extends battery life, so your monitor is ready when you need it.
- • **Calibrated for Confidence:** Factory calibrated with easy recalibration option keeps readings reliable and accurate.
- • **Effortless Filter Management:** Know exactly when to replace filters—no guesswork, no wasted resources.
- • **Precision Water Quality Insight:** Real-time TDS monitoring ensures your water is always pure and safe.

## Overview

The HM Digital SM-1 is a compact, battery-powered inline TDS monitor designed for single water lines. Featuring a wide measurement range up to 9990 ppm and advanced microprocessor technology, it delivers precise water quality readings. Its quick-connect fitting allows easy installation in reverse osmosis and other filtration systems, while the auto-off function conserves battery life. Factory calibrated and user recalibratable, it’s the smart choice for proactive water purity management.

## Description

HM Digital SM-1 In-Line Single TDS Monitor, 1/4" Tee, SM1 FEATURES Displays TDS level of a single water line. 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. Wide Range 0-9990 ppm (From 0 - 999 ppm the resolution is 1 ppm. From 1000 to 9990 ppm, the resolution is 10 ppm, indicated by a blinking 'x10' image.) Factory Calibrated: our meters are calibrated with a 342 ppm NaCl solution. Meters can be recalibrated with a mini-screwdriver. Comes equipped with John Guest Quick-Connect T-fitting (1/4 inch standard). Installs quickly and easily. NEW PRODUCT!

Review: Replacement. - Replacement meter exact match.
Review: Great monitor - Great for continuous monitoring water quality of product water on watermarked on sailboat

## Features

- Measure the product water at any time.
- Use the monitor to determine when the filters need to be changed.
- Ideal for any water filtration system, including reverse osmosis systems, coolers and much more.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B00H1267XY |
| Batteries | 2 LR44 batteries required. |
| Best Sellers Rank | #71,196 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #16 in Water Purification System Accessories #427 in Substance Analysis Instrumentation |
| Brand | HM Digital |
| Date First Available | July 8, 2013 |
| Installation Type | Under Sink |
| Is Discontinued By Manufacturer | No |
| Item Weight | 2.39 ounces |
| Item model number | SM-1 |
| Manufacturer | HM Digital |
| Model Name | SM-1 |
| Package Dimensions | 5.35 x 4.17 x 0.79 inches |
| Package Information | Cartridge |
| Power Source | Battery Powered |
| Purification Method | Reverse Osmosis |
| Special Feature | Built In TDS Meter |

## Product Details

- **Brand:** HM Digital
- **Included Components:** Battery
- **Installation Type:** Under Sink
- **Manufacturer:** HM Digital
- **Material:** Plastic
- **Model Name:** SM-1
- **Package Information:** Cartridge
- **Power Source:** Battery Powered
- **Purification Method:** Reverse Osmosis
- **Special Feature:** Built In TDS Meter

## Images

![SM-1 1-Stage Inline TDS Monitor For Single Water Line - Image 1](https://m.media-amazon.com/images/I/41soFBslGcL.jpg)

## Questions & Answers

**Q: Can I just dip the probe in water or does it have to be use with tubing?**
A: You can use this in either way.

**Q: what's the accuracy of the measurement?**
A: Hi Rick A. I expect to receive the item this upcoming Sunday, once I install it,I will give you feedback, I have purchased several items from HM, such as a inline tds and am finding good results as far as accuracy with in 10 tds from the hand held meter.

**Q: can this be used on a 1" copper water main and if so, if I was to insert a 1" copper T, how close does the sensor need to be to the water flow?**
A: Hi, if you are talking about the HM gallons meter, it could be installed with a 1" tee if you can also add a 1/4 fitting either push in type, or a threaded reduced fitting to recieve a push in pvc 1/4 npt. You can also forget the tee and use a pierce fitting on the line that is commonly used to get water to a evaporated cooler. The line should go to the in only feeding the Ro system so your not measuring all of the water being used for everything else. I hope this helps and makes sense.

**Q: What is the size of the display?**
A: It's small... approx. 10mm x 20mm, but it's very easy to read.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Replacement.
*by S***S on March 23, 2025*

Replacement meter exact match.

### ⭐⭐⭐⭐⭐ Great monitor
*by J***. on December 16, 2020*

Great for continuous monitoring water quality of product water on watermarked on sailboat

### ⭐⭐⭐⭐ Works great and fits perfect
*by S***N on March 23, 2025*

The product has met expectations and was delivered much faster than expected. The setup was simple, and I recommend it to others. I'm sure I'll be buying from you again.

## Frequently Bought Together

- HM Digital SM-1 1-Stage Inline TDS Monitor For Single Water Line
- AquaticLife Float Valve Kit for RO & RO/DI Systems
- HM Digital DM-1 In-Line Dual TDS Monitor, 0-9990 ppm Range, +/- 2% Readout Accuracy,Blue & White

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*Product available on Desertcart Thailand*
*Store origin: TH*
*Last updated: 2026-02-23*