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Extech PH90 Waterproof PH Meter

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$140.47

$ 59 .99 $59.99

In Stock

1.Style:Ph90


  • Rugged replaceable flat surface pH electrode for quick on-the-spot pH measurements
  • Simultaneous display of pH and Temperature
  • 2 or 3 point calibration automatically recognizes buffer solutions (order pH buffers separately)
  • PTS (percent of slope) tells you when it's time to replace your electrode (below 70% or above 130%)
  • Automatic Temperature Compensation


PH90 is a waterproof pH meter. Featuring a rugged, waterproof (IP57) housing with Flat surface electrode for measuring pH in liquids, semi-solids, and solids and also displays temperature on the large LCD. The electrode does not break or get junctions clogged like the traditional glass bulb probes. Easy to replace sensor is perfect for field or lab use. Features a 2 or 3 point calibration, which automatically recognizes buffer solutions, and PTS (percentage of slope) tells you when it's time to replace your electrode. Complete with Flat surface pH electrode, protective sensor cap, and two 3V CR-2032 button batteries (pH Buffers are required for calibration - sold separately).


Berit Borrmann
Reviewed in Germany on November 15, 2019
Super Teil schnelle Leferung funktioniert seht gut und schnell. WSürde ich wieder kaufen, bei bedarf.
JB
Reviewed in the United States on February 11, 2017
Seems to work pretty well. It has held its calibration well. It takes a while for its temperature to equilibrate with whatever you are measuring, and the pH reading does change noticeably as the temperature changes in most cases, so I find that it takes a minute or so to get a reading (unless it's already equilibrated, in which case a measurement only takes a few seconds).
Sierra Gentleheart
Reviewed in the United States on December 23, 2016
Whether you want to test the pH of planting soil or facial exfoliating creams, this meter will meet your needs. I have wanted one for a very long time, but have made do with pH test strips, which were never 100% satisfactory. This Extech pH90 waterproof pH meter is at least 100% satisfactory! It is so easy to use you may think the directions are too simple. Basically you rinse it, turn it on and measure. I'll be using it extensively in the spring when planting our vegetable garden and fruit trees. Until then, I wanted to check the pH of some exfoliating creams that need to be in the 3.2 to 3.8 range in order to be effective. Since the meter measures very accurately, I was able to determine that the two creams measure 3.50 and 3.75. I double-checked with the pH test strips I had on hand and got a much more general reading in that same range. I also gave up bar soap a few months ago in favor of liquid bath wash because the latter has a lower pH that is better for skin. I found that the body wash I prefer had a pH 1.5 points lower than a second body wash that didn't feel as good to me. So my subjective experience of the body washes was consistent with the objective reading from the pH meter. The skin rashes that plagued me when I used bar soap are long gone now, so I will continue to test washes, lotions, and creams to make sure their pH is in the lower range that I prefer. This meter is going to be great for that purpose.While the meter arrived precalibrated, I will need to recheck calibration periodically, so I bought some buffer solution, which is not included. I chose to get the available on Amazon because I don't want a lot of buffer solution sitting around. I think I still have a lot to learn about pH, but this meter is an excellent tool that should serve me in that process.
Richard C. Drew
Reviewed in the United States on November 9, 2016
We have around 3/4 of an acre around out house with lots of planting areas and a man-made Koi pond. We test the water in the pond weekly, and test the soil when planting new plants. For the pond it's been one of the cheap bulb sensors, and a test strip for the soil. This meter works on liquids, semi-solids and solids - that means I can test the pond and the soil with a single meter - no more test strips.The display is easy to read and calibration is quick and simple. I do have a couple of complaints - the display is not backlit. Since the display is set back about 1/4" from the housing, it can be difficult to read outside or in bright light - not because the display is dim, but because of the shadow cast by the housing. You have to change the angle a few times to read the numbers in bright sun. Easy enough to see if you change the angle of the meter a little, but worth mentioning. Next is that the sensor can be replaced - great idea - but after 30 minutes of searching the web and the manufacturers site, there's none to be found. It's in their catalog (Part PH95) but nowhere else. There are other replacement modules for other pH meters that cost between $50 and $65. If that's the price for the PH95 it seems expensive. The instructions do mention that the module will have to be replaced eventually.The meter uses two 2032 button batteries - included. These are probably the most common button batteries available and a pair costs around $5. There's no case or pouch for the meter, so you can't just toss it in your test kit or tool box. The display lens and button covers are a single piece of flexible plastic. My finger-nail was able to but a permanent crease in the lens without much effort - I would be able to puncture it with a good press. The entire meter is really heavy duty - except for the lens and buttons. Drop the meter from a few feet and it will shrug it off. If any part of the face hits a rock, edge of the pond, etc. you'll probably break the meter. It's like a windshield on a tank.Accuracy and ease of use, a solid 5 stars. Overall build quality, 4 stars. Display: Lack of backlight, deep off-set from the face, and really thin "lens", three stars.
Thomas B. Gross
Reviewed in the United States on November 27, 2016
I'm very excited by my new-found ability to measure the PH of all kinds of things. My primary interest in this device was originally for testing the PH of my lawn soil, which I have always suspected is just not right (based on how much difficulty I have growing grass). So I first mixed some dirt with water to measure its acidity - it does appear to be alkaline. Just for fun I also measured the acidity of cider vinegar (guess what: its PH is very low) as well as tap water, tap water with baking soda, and then cider with baking soda (which, I discovered, is how you can make a volcano). All great fun and really neat, I think.The instructions that come with the device are a bit obtuse, or at least I found them confusing. Basically you keep the probe in a cap with a moist piece of sponge, and then you put the probe in different solutions (or, I think directly in dirt, for example). I have been going wild measuring the acidity of all kinds of things, from cottage cheese to single malt scotch. I am attaching some photos of my preliminary research.
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