Can I just dip the probe in water or does it have to be use with tubing?

You can use this in either way.

what's the accuracy of the measurement?

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.

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?

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.

What is the size of the display?

It's small... approx. 10mm x 20mm, but it's very easy to read.

Fully operational. Shipping worldwide, on schedule.Duty & taxes paid at delivery

Help Track order

Account Cart

Fully operational. Shipping worldwide, on schedule.Duty & taxes paid at delivery

Help Track order

Account Cart

SM-1 1-Stage Inline TDS Monitor For Single Water Line

Product ID: 30178917

Details

Brand
HM Digital
Included Components
Battery
Installation Type
Under Sink
Manufacturer
HM Digital
Material
Plastic
Model Name
SM-1

💧0-9990 ppm TDS range

🔋Auto-Off battery saver

⚙️Advanced microprocessor accuracy

Buy anything from 5,000+ international stores. One checkout price. No surprise fees. Join 2M+ shoppers on Desertcart.

$57.78

Duties & taxes included

In stock

Sold byAmazon USADelivered byDesertcartCustomer service byDesertcartReturns14 days · 30 with PRO

Buyer Protection · Full refund if your order doesn't arrive as described.

Desertcart purchases this item on your behalf and handles shipping, customs, and support to USA.

Secure transaction

Description

💧 Stay ahead of impurities—monitor your water like a pro!

SMART POWER EFFICIENCY - Auto-Off feature extends battery life by shutting down after 10 minutes of inactivity.
EFFORTLESS INSTALLATION - Quick-connect 1/4" John Guest T-fitting means no plumber needed—get up and running fast.
UNIVERSAL COMPATIBILITY - Seamlessly integrates with reverse osmosis systems, coolers, and any single water line filtration setup.
CALIBRATED FOR CONFIDENCE - Factory calibrated with NaCl solution and user recalibration option ensures trusted accuracy every time.
PRECISION WATER QUALITY INSIGHT - Real-time TDS readings up to 9990 ppm keep your hydration pure and your filters optimized.

The HM Digital SM-1 is a battery-powered inline TDS monitor designed for single water lines, offering precise total dissolved solids measurement from 0 to 9990 ppm. Featuring advanced microprocessor technology, an auto-off function to conserve battery, and easy installation with a John Guest quick-connect fitting, it’s ideal for reverse osmosis and other filtration systems. Factory calibrated and user recalibratable, it empowers professionals to maintain optimal water quality effortlessly.

Specifications

ASIN	B00H1267XY
Best Sellers Rank	#158,054 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #52 in Water Purification System Accessories #913 in Substance Analysis Instrumentation
Brand	HM Digital
Brand Name	HM Digital
Container Type	Cartridge
Customer Reviews	4.4 out of 5 stars 30 Reviews
Included Components	Battery
Installation Type	Under Sink
Manufacturer	HM Digital
Material	Plastic
Material Type	Plastic
Model Name	SM-1
Model Number	SM-1
Other Special Features of the Product	Built In TDS Meter
Package Information	Cartridge
Part Number	343433
Power Source	Battery Powered
Purification Method	Reverse Osmosis
Special Feature	Built In TDS Meter

Reviews

S**S

23.03.2025

J**.

16.12.2020

S**N

23.03.2025

J**L

8.03.2025

B**D

10.03.2022

Common Questions

Are the products genuine and authentic?+

Yes, all products are sourced directly from authorized retailers in the US, UK, UAE and India. We maintain strict quality control processes and verify each product before shipping. All items come with applicable manufacturer warranties and are covered by our standard return policy.

How long does delivery take and is it reliable?+

Delivery times vary by destination country, typically ranging from 3-9 business days. Each order is fully trackable through our system. We handle all customs clearance and use reliable courier partners for last-mile delivery. You'll receive regular updates about your order status via email and our app.

What is Desertcart? Is it safe to order from?+

Desertcart is an international e-commerce platform operating since 2014. We securely process thousands of orders globally each day. Every product goes through our quality verification process before delivery, and we provide end-to-end order tracking, 24/7 customer support, and a comprehensive returns policy to ensure a safe shopping experience.

How is product pricing calculated?+

Our prices include the product cost, international shipping, import duties, customs clearance, and local delivery charges. We handle all customs and import procedures, ensuring there are no hidden fees upon delivery. PRO members receive additional benefits including free shipping.

Trustpilot

TrustScore 4.5 | 7,300+ reviews

Meera L.

Smooth transaction and product arrived in perfect condition.

3 weeks ago

Rajesh P.

Customer service was outstanding when I had questions about the product.

2 days ago

View all Trustpilot reviews

Shop Global, Save with Desertcart

Value for Money

Competitive prices on a vast range of products

Shop Globally

Serving millions of shoppers across more than 100 countries

Enhanced Protection

Trusted payment options loved by worldwide shoppers

Customer Assurance

Trusted payment options loved by worldwide shoppers.

Desertcart App

Shop on the go, anytime, anywhere.