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.

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HM Digital 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 power saving

⚙️Advanced microprocessor accuracy

R1024

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Sold byAmazon South AfricaDelivered byDesertcartCustomer service byDesertcartReturns14 days · 30 with PRO

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Description

💧 Stay ahead of water quality—because pure water is non-negotiable!

SEAMLESS INSTALLATION - Quick-connect 1/4" John Guest tee fits any standard water line in minutes.
SMART POWER EFFICIENCY - Auto-off feature conserves battery life, keeping your device ready when you need it.
UNIVERSAL COMPATIBILITY - Perfect for reverse osmosis systems, coolers, and all water filtration setups.
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.

The HM Digital SM-1 is a battery-powered, inline TDS monitor designed for single water lines. Featuring a wide measurement range of 0-9990 ppm with high accuracy via advanced microprocessor technology, it provides real-time water quality data. Its quick-connect 1/4" tee allows easy installation under sinks or filtration systems, while the auto-off function extends battery life. Factory calibrated and recalibratable, it’s ideal for reverse osmosis and other filtration systems to ensure optimal water purity and timely filter changes.

Specifications

ASIN	B00H1267XY
Best Sellers Rank	#241,267 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #143 in Water Purification System Accessories #1,266 in Substance Analysis Instrumentation
Brand Name	HM Digital
Container Type	Cartridge
Customer Reviews	4.1 4.1 out of 5 stars (32)
Included Components	Battery
Installation Type	Under Sink
Manufacturer	HM Digital
Material Type	Plastic
Model Name	SM-1
Model Number	SM-1
Number of Items	1
Other Special Features of the Product	Multi Stage Filtration, Reduce TDS, Auto-Off function, Advanced Microprocessor Technology
Part Number	343433
Power Source	Battery Powered
Purification Method	Reverse Osmosis
Unit Count	1 Count

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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.

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R1024

Duties & taxes included

In stock

Sold byAmazon South AfricaDelivered 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 South Africa.

Secure transaction

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TrustScore 4.5 | 7,300+ reviews

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