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💧 Measure Like a Pro, Anywhere, Anytime!
The Extech RE300 ExStik ORP Meter is a professional-grade, waterproof oxidation-reduction potential tester featuring a rugged flat surface electrode for reliable measurements in diverse media. It offers precise 1mV resolution across a wide range (-999 to 999mV) with ±4mV accuracy, stores up to 15 readings with tags, and displays real-time trends via an analog bargraph. Designed for field durability with an IP57 rating, it floats if dropped in water and supports interchangeable sensor modules for expanded testing capabilities. Ideal for pool, spa, and water quality professionals seeking dependable, lab-quality results on the go.



























| ASIN | B000S8UIVA |
| Batteries | 4 Lithium Metal batteries required. (included) |
| Batteries Included? | Yes |
| Batteries Required? | Yes |
| Battery Cell Type | NiMH |
| Best Sellers Rank | #123,179 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #9 in Dissolved Oxygen Meters & Accessories |
| Color | Blue/Grey |
| Customer Reviews | 4.1 4.1 out of 5 stars (32) |
| Date First Available | June 20, 2007 |
| Description Pile | 4 × CR2032 (3V) batteries |
| Included Components | Meter, Batt, Case |
| Is Discontinued By Manufacturer | No |
| Item Package Quantity | 1 |
| Item Weight | 4.2 ounces |
| Item model number | RE300 |
| Manufacturer | Extech |
| Measurement Accuracy | +/-0.5% |
| Mounting Type | Surface Mount |
| Number Of Pieces | 1 |
| Part Number | RE300 |
| Power Source | Battery Powered |
| Product Dimensions | 0.75 x 0.75 x 200.1 inches |
| Style | RE300 |
| Voltage | 3 Volts |
| Warranty Description | 2 years |
N**E
Eficiente, práctico y confiable.
S**U
Worth it
Accuracy and value for money
L**S
Worked great, then malfunctioned
For over a month, this ORP meter performed like a champ. The other day, after submerging about 1/2 into water for a test, the meter refused to "Self Check" when turned back on. After disassembly, I found moisture in the compartment where the module plugs into the stick. Blew out, let dry a few hours and the unit returned to self check properly. Today, the unit failed to self check and, upon calling FLIR, the tech ran me through a "software reset" which did not fix the problem. I was then connected to a CSR who asked for my invoice and said that a new unit would be sent to me ASAP. The service was excellent, i received the new item in a timely manner It would appear that this unit is really not well enough designed for regularly swapping out the ORP module with the pH module and maintaining waterproof status. I recommend that you make sure the unit is tightly assembled upon receipt and, if you need a pH meter, to purchase a separate product. I will use this unit to only check ORP and will not submerge beyond the module locking nut.
S**N
Too technical to use
I wanted to use the meter in demonstrating the ORP in ionized water, compared to tap water. It took too long to get to the reading of the ORP, it also did not give an accurate reading when it was in the minus range. Plus the minus range only went to - 100. Some of the ionized water samples were - 200 and more, the Extech meter could not give those readings.
A**N
Soil Testing
This device is awesome. It is compact, accurate and reliable. It is easy to use and maintain, and provides readings relatively fast.
M**N
The best ORP meter
This product is the highest quality. Many meeters have exposed electrodes that can get damaged too easily. The construction is excellent.
P**R
Purchased the RE300 from T. E. Dep. ...
Purchased the RE300 from T.E.Dep. and was shipped a unit with a dry probe. Unit provided inconsistent and unreliable readings. T.E.Dep. refused to take it back (was at day 45 from purchase) so they brushed me off with the "no returns period" statement and pointed me to the manufacture to get it replaced. Contacted manufacturer and was shipped a replacement probe which turned out to be even more unreliable than the one it was replacing. The replacement unit gives readings all over the place when sampling the same solution over and over. If the probe is left in the sample, it will give a reading of 0mv after about 3 minutes. Contacted manufacturer again (Frank) and was given a "that's interesting" response when I explained the results I was getting. He forwarded me to Tech Support where I ended up in voice mail. I called right back and the lady who answered the phone made arrangements to send me another replacement. If the 2nd replacement works, I'll adjust my rating accordingly. Just received the replacement of the replacement and it too is absolutely unreliable. Soak in distilled water (or tap) for 10 minutes, turn on, swish into solution to be tested, wait 1 to 3 minutes for stable reading. Reading never stabilizes and removing the probe, turning it off and back on again and into the solution gives yet a different reading than the one just before it and it is off by over 50 Mv. The unit is made in china and I'm betting that the age of the probe having traveled that far may have a lot to do with why it doesn't work. It may be simply too old. I'm going after a refund now. I'm sick of wasting my time. When I shell out 100 bucks for a probe, I expect it to work.
C**B
Unreliable
They need to add more In depth instructions. My meter is reading all over the place. I’ll add hupochlorousacid and it goes down. Started displaying ph for some reason. Gremlins. Trying to problem solve or get refund.
R**D
Instable au niveau des résultats. Beaucoup de variations sur une même solution. Je pense que le produit n'est pas fiable ou l'électrode endommagée.
E**K
Buen articulo y buen precio
K**G
Not very accurate when tested in calibration fluid and is a bit inconsistent. But for the price it is good enough if your not looking for pinpoint accuracy.
Trustpilot
4 days ago
2 days ago