

💧 Take control of your water quality like a pro — precision, speed, and durability in one sleek meter!
The HM Digital HMDCOM100 is a professional-grade, waterproof EC/TDS/Temperature combo meter designed for precise water quality testing across diverse applications including hydroponics, pools, spas, and labs. Featuring a fast 0.5-second response, multiple calibration options, and a rugged IP67-rated housing, it delivers reliable, customizable readings in a compact, easy-to-use form factor.
| ASIN | B0045LQFTK |
| Age Range (Description) | Adult |
| Batteries | 2 AAA batteries required. |
| Best Sellers Rank | #65,581 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #12 in Conductivity Meters & Accessories |
| Brand | HM Digital |
| Color | White/Purple |
| Date First Available | December 7, 2005 |
| Display Type | Digital |
| Global Trade Identification Number | 00891144000007 |
| Immersion Depth | 1 Meters |
| Included Components | HM Digital HMDCOM100 Waterproof EC/TDS And Amp Temperature Combo Meter |
| Indoor/Outdoor Usage | Outdoor |
| Is Discontinued By Manufacturer | No |
| Item Length | 8.9 Inches |
| Item Weight | 4.2 ounces |
| Item model number | COM-100 |
| Manufacturer | HM Digital |
| Model Name | COM-100 |
| National Stock Number | 4910-01-620-0848 |
| Number of Batteries | 2 AAA batteries required. |
| Outer Material | Plastic |
| Power Source | Battery Powered |
| Product Care Instructions | Wipe Clean |
| Response Time | 0.5 seconds |
| Reusability | Reusable |
| Special Feature | Auto-off function, data-hold function and low-battery indicator., Display: large and easy-to-read LCD screen includes simultaneous temperature reading., Factory Calibrated: The COM-100 meter is calibrated with a 1413 µS solution. The meter can be recalibrated with digital calibration using the push buttons, rather than a screwdriver. |
| Specification Met | UL |
| Style | Practical |
| UPC | 095225177507 891144000007 |
| Unit Count | 1.0 Count |
| Upper Temperature Rating | 130 Degrees Fahrenheit |
B**8
I love it
FWIW, I'm writing the review from the POV of a spa user. You can use this tester for your pool, salt water aquarium or your hydroponic planter. My supposition is, you're looking at this item because you have needs above and beyond simple test strips. With this TDS meter you'll be able to quickly tell what your total dissolved solids (TDS) are. HM also has a pH meter, the PH-200, which I've been enjoying for a few days now. The unit is waterproof, light weight, a bit smaller than the size of a small "C" cell flashlight or about the size of a large cigar. It's easy to use, easy to maintain, small form factor for storage purposes and once calibrated, I feel it's an accurate piece of test equipment that gives you the feel of having control over your spa tub water chemistry. If you're a bit geeky, enjoy the feel of accurate test data and like the peace of mind knowing you have control over your water chemistry, after using this tester a few times, you'll feel confident that you're finally in control of your spa water readings. Yes, the COM-100 is a bit expensive, but if you have the extra green, for the peace of mind and control over your water chemistry this tester gives you, you'll quickly come to the same conclusion I came to; money well spent. Note 1. Be sure to buy some calibration solution so you know your reading is accurate. Calibration is simple. Holding the middle button in for a few seconds puts the unit in calibration mode and then it's simply using the up/down arrows to set the digital display to match the calibration fluids stated concentration level. In this case the calibration fluid concentration is 342ppm. You want to use a calibration fluid that's close to your expected needs. In the case of this tester, calibration is no more difficult than using a television remote control. Note 2. Amazon has "HM Digital Calibration Fluid for Handheld TDS Meter" for sale. You can get calibration fluid in concentrations of either 1000 ppm or 342 ppm. You can get in KCl or NaCl depending on what your water chemistry is. Note 3. FWIW, you want your spa water to be between 1000 - 2000 ppm TDS. When it gets above 3000 ppm, it's time to trash the spa tub water because at 3000 ppm, your chemicals become less effective. Knowing TDS is an important aspect of monitoring your spa water chemistry. Without a TDS tester of this kind, you haven't a clue what your TDS is. Due to this, you're either having to trash your water prematurely on a monthly, two or three month cycle. Or the alternative is, use up a lot of time regularly dropping in at your pool/spa supply house with water sample in hand like the doctors office where they're going want you to spend more money. I hate trashing spa water and I hate spending money on chemicals, just so I feel good about getting my water tested for free. With this tester, that's no longer an issue. Hope the above helps.
A**R
Great for testing water quality and hydroponic solutions
Works as stated. Its nice to have different conversion scales (NaCl, KCl, 442). For testing total disolved solid (TDS) aka Part Per Million (PPM), this meter is very accurate within + or -2 . For testing water quality and hydroponic solution strength, most companies recomend the NaCl scale. Fast delivery, clear instruction manual, completely water proof, and interchangeable electrodes...quality product.
A**S
It’s good
Good product. Complicated a bit and needs better instructions
T**U
Works as described
Priced at 60 is darn good for what it is. Measure a bit slow for some liquid at different temperature however according to manual it is to be expected up to 5 min for the first read of that temp and liquid type. Virtually tough but it's not a hammer so dont abuse it keep it in it's case. It's not a PH meter so I dont see you have to keep it moist at all time. Shakes dry for storage fast and easy. It has a fast self calibration for use though I have not had the need to use it yet. Has both Fahrenheit and Celsius read, also measures micro siemens. Easy battery exchange. Conclusion Fair construction, reasonable priced, exchangeable detector heads and decent accuracy outta factory.
M**E
7 years in service and still going strong
This EC meter is great for a range of applications. I have used it for water quality testing, horticulture, and for experimentation. Also did I mention I have been using the same meter for a little over 7 years with zero malfunctions. All I've had to do is chanhe the battery and clean the probes every so often. I love that it's waterproof since I have dropped it in water a few times amd the seals are still holding up even after 7 years of use. Would definitely recommend this meter.
M**E
Good quality, calibration out of the box was correct
Easy to use, accurate to industry standards of +/- 2%
E**E
Reliable Product
Reliable. Recommend it. Consistent reading.
R**N
Hope you can afford to replace the batteries often!
I was excited to get this unit and it seemed like a great product, however, after one use I turned it off to store it and the next time I went to use it the batteries are dead! I thought "operator error" and replaced these very expensive batteries and it began working again. I used the device, very diligently cleaned and turned it off, making sure to show my brother that I had turned it off. I went to use it again and the batteries are dead once again! Unfortunately I don't use it often enough that I can send it back for replacement so my advice is don't buy this product! I found one user review that had the same issue.
B**M
Great meter. Near instant readings, accurate, easy to calibrate and best of all, waterproof. I’ve accidentally dropped the whole meter into water, completely submerged for a few seconds with no problems.
J**I
تجربتي معه جيدة
S**L
Great product for checking water quality.
A**.
Es un medidor TDS profesional, calibrable y con electrodos de platino recambiables. No es un juguete. Si necesitas un TDS fiable, este es suficiente hasta para una tesis de investigación. Yo lo uso en acuarios porque es calibrable y la temperatura y tds me han dado exactos, contrastados con un instrumentos de laboratorio que solicite para comparar.
D**4
Parfait
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