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HM Digital PH-200 Waterproof pH and Temperature Meter

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HM Digital PH-200 Waterproof pH and Temperature Meter

(41 customer reviews)

SKU:

657

In Stock

Availability: Usually ships in 1 business days

Hydrofarm hmdph200 waterproof ph and temperature meter

List Price:	$129.99
Our Price:	$80.69 & this item ships for FREE with Super Saver Shipping.
You Save:	$49.30 (38%)

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Product Details

Product Length:	2.0 inches
Product Width:	8.5 inches
Product Height:	3.3 inches
Product Weight:	0.39 pounds
Package Length:	9.2 inches
Package Width:	3.2 inches
Package Height:	2.1 inches
Package Weight:	0.4 pounds
Average Customer Rating:	based on 41 reviews

Features

Measures pH and temperature
Auto ranging 3 point calibration with digital fine tuning
Simultaneous temperature display
Measurement range 0-14 pH

Customer Reviews

Average Customer Review: 3.5

( 41 customer reviews )
Write an online review and share your thoughts with other customers.

Most Helpful Customer Reviews

57 of 59 found the following review helpful:

good quality- reasonable price May 28, 2010 By W. Wygant
I have been using this unit for approx. a month now and so far I am impressed with this unit. Although I purchased this meter for my own personal use, I also work in a professional lab during the day. I compaired this units results with our $1500 meter in the lab and found that this unit is very close in accuracy. The statements about this unit being hard to calibrate are incorect. Having experience with several kinds of pro ph meters I can say with authority that this unit is as easy as it gets to calibrate. I would guess that the other folks here who had trouble probably had defective units. The calibration process is so simple that a person would be hard pressed to screw it up unless you didn't read the manual at all. One other nice feature of this unit is the two decimal point readout. The other units in this price range that are for sale here only have one decimal point display. example-- 7.XX vs. 7.X This feature will be very helpful to anyone who is considering tight control of the solution you are working with. Remember, for every full point that your ph goes up or down your solution is 10 times more acidic or alkaline. example-- 7 vs. 8 ph. Therefore, with a unit that only reads out to one decimal place, for each number movement your solution is twice as acidic or alkaline example--7.1 vs. 7.2 ph and that isn't even taking into account the margin of inaccuracy in these consumer grade units. The only weakness I have found in this unit is that it has auto shut off and likes to turn itself off while I'm in the middle of a reading. The truth is that it is more of a plus than a minus. Considering that if you forget to turn this thing off, the next time you attempt to use it the batteries will be dead and that would be a much bigger pain in the butt than having to hit the power button once in a while, to say nothing of having to buy a new probe tip prematurely because all probe tips have a useful life based on time of use among other things. The other units in this range may be cheaper but the quality and feature designed into this unit make it worth the extra money.

33 of 33 found the following review helpful:

Great Meter! - WARNING: Common Sense Required! Jun 28, 2011 By The Resident Gourmet
I assume that most of the folks who have broken this quality probe or complained about how fragile it is have never used a quality/accurate PH meter before. The nature of the beast requires that the sensor be made the way this one is, and also that it remain wet with a storage solution at ALL TIMES! There is no gray area here folks! If you fail to rinse the end of the probe off with a spray bottle of distilled water after each use and then store it in the special reservoir cap with the sponge to hold the storage fluid up against the glass/gel sensor, YOU ARE ASKING FOR TROUBLE!

The original unit I bought (Not from Amazon) arrived dry as a bone with the storage solution evaporated. I returned it for a refund and purchased the meter from another dealer who took better care of his stock. If your meter arrives dried out, I would suggest doing the same thing. Although the sensor can sometimes be rehydrated, I would be dubious as to the accuracy and prefer to get a replacement that was stored properly and/or didn't sit on a dealer's shelf for an eternity.

In terms of the fragility of the glass sensor itself... The sensor end of the probe has a three sided housing that is designed to extend out beyond the actual glass sensor bead and shield it from impact from the sides, but obviously, if you manhandle the thing like a Gorilla and carelessly dunk it into a glass beaker or other container, there is a good chance that you are going to bring the sensor bead straight down onto the rim of the container or something and crack or shatter the sensor! DUH!! This thing is definitely not IDIOT PROOF, so idiots should probably look for something else or have someone with better hand/eye coordination do their testing for them!

I purchased my original PH-200 well over two years ago and use it several times a day in my hydroponic garden. NEVER broke a sensor, never had one dry out, never had a problem with calibration, never had a problem with the device in any way! I like this brand and this model so much, I just bought another one here on Amazon because my original is getting close to needing a sensor replacement, and I had a gift card here and figured it would make sense to just buy an entire new unit for now and a new sensor for the original later!

The auto calibration is GREAT! Buy yourself some calibration reference solution of 4.0 and 7.0 PH and READ THE INSTRUCTIONS ON THE LABEL ON HOW TO CALIBRATE the device. Unlike other meters in this general price range, there is no calibration screw to turn, no hassles at all! Just hold the CALIBRATE button down while the probe is immersed in the "quality" reference solution of your choice, and wait till the display reads "END". Takes about 5 seconds from start to finish after letting the sensor sit in the reference solution for a FULL MINUTE before hitting the button!

DON'T DO WHAT MOST OF THE 1 AND 2 STAR REVIEWERS HERE DID AND CONTAMINATE THE CALIBRATION REFERENCE SOLUTION, AND THEN WHINE ABOUT THE UNIT FAILING TO CALIBRATE PROPERLY!

Some lab guys calibrate before every test, and with this model, it is so easy to do, it really can be done in less than 5 seconds by pushing a button and waiting for the probe to self calibrate to the solution it is sitting in. It uses its PH measuring ability to identify the PH of the base solution you are using and calibrate accordingly. (7.0 or 4.0) In terms of accuracy... Like one of the other owners said... This thing is almost as accurate as the $1500.00+ lab grade PH meters, which is definitely saying something!

So... Like anything, the device is only as good as the person using it and most of the low review scores are testament to how NOT TO USE THIS DEVICE! If you treat your equipment like crap and don't like reading owners manuals then this probe is probably not for you. If on the other hand, you are looking for an excellent WATER PROOF probe made by a company well respected in the laboratory equipment industry, a model that is considered by those who should know to be one of the best PH probes you can buy, then look no further than the PH-200.

And when your unit arrives... READ the manual, and use some COMMON SENSE in handling it and it should give you years of trouble free service!

I would give this thing 10 stars if I could, it is that good!

23 of 23 found the following review helpful:

Great product Nov 30, 2009 By Robert L. Baker
I noticed that someone said that this meter is difficult to calibrate. I thought so too until I read the instructions, it's actually a dream to calibrate. It figures out what pH your fluid is and automatically calibrates to that, works really well. Having said that, if you don't know about this feature, calibration is a pain because you have to click the down arrow like a million times. Read the instructions, will save you a lot of trouble.

Meter is great, it even came with a little packet of powder to make calibration fluid AND and little solution to use in the cap to keep the electrodes wet (very important). Love this meter and their PPM meter as well.

I wish the "hold" button was on the top of the unit, otherwise 5 stars.

10 of 10 found the following review helpful:

Works like a charm Sep 06, 2008 By A. Lewis "CAPT Popeye"
This item is working for me perfectly every time, simple to use and self storing in a safe enclosure. I need to use it in the rain so I appreciate the waterproofing. Easy to replce the head piece, so overall, 5 stars from me.

11 of 12 found the following review helpful:

Notes on using the PH-200 Dec 16, 2010 By BUYER
HM Digital Meters Waterproof pH/Temperature Meter

I received the pH meter with a dry head - the buffer solution in the cap fully evaporated; the instrument settles measurements not in the specified 30 seconds, but more like in 3 minutes (I fully clean and dry the reference and measurement probes on the tip of the instrument before each use).

There are indeed some O-rings that are supposed to prevent moisture from getting into the battery compartment or inside the measurements tip when maneuvering the instrument. However, one has to definitely avoid stream washing the tip while holding the instrument upwards: this will let moisture get inside the tip and create significant measurement errors (I would not call this device waterproof; since it cannot withstand a stream of water in the probes area it would not truly qualify even for the IP66 standard). Before each measurement, one needs to clean and dry the pH reference and pH measurement probes and insure that the display is showing dashes, not numbers, in the pH area.

I also found that calibrating with a standard reference solution of pH 4.01 generates significant better results - at least for the acidic pH range, than after calibrating with the pH 7.0 reference solution. I used "General Hydroponics" standard solutions:
1)If the instrument is calibrated on pH 7.0 reference solution, then it will read the pH 4.0 reference solution as being of pH 3.92 (I did this calibration several times - cleaned and dried heads each time, the stable readings - after 3 minutes, were consistent)
2)If the instrument is calibrated on pH 4.01 reference solution, then it will read the pH 7.0 reference solution as having a pH of 6.99 (again, ran several calibrations with consistent final readings)
The above results in (1) may look a bit surprising, however - if considered normal, then one could conclude that a calibration with a pH 7.0 reference solution would also yield more precise readings for basic solutions (this needs to be verified though)

The dual pH/Temperature display makes comparison measurements meaningful, particularly for temperatures less than 25degC or larger than 45degC, where there is an increased dependency of pH measurement with liquid temperature. A temperature compensation of the pH measurement seems to be implemented, but is more effective in the 25-45degC range. For a liquid with (pH7.29 at 1.5degC), the pH dropped to (7.12 at 15degC) to (7.05 at 25degC), hit a bottom (pH7.02/7.03 between 35-45degC) then started to rise after 45degC to read (7.08 at 52.5degC) where I stopped.

As far as other functional features, the one that I would have liked to be different is the automatic shut down timing, which should be programmable to allow for observation of longer processes. The default (and only) time-out value proved to be short for what I needed to do so far, and whenever one changes the position of the instrument in the liquid (to turn the meter back on), a temporary instability in the pH reading occurs.

The assembly is sturdy enough for daily usage and I did not have major issues handling it or pressing its buttons. I have been using the instrument almost each day for a month now.

See all 41 customer reviews on Amazon.com