Cheapest digital pH-meter(and EC) review...

...Costs from ~€10<. Anyway, since I bought these as a kit, and that they're almost identical in construction, you can see this as a review for both the pH, and the EC-meter. These digital meters are usually called "Budget *meter", when marketed, no real brand. Some resellers have stamped their own name on them. It's the same construct altogether though.

Been using these now for almost three weeks. No problems what so ever. It seems to be "no name"-meters, since googeling doesn't help me find the "brand". Called "budget" in most places its sold. And it really is budget, but it's also all you really need.(..and _nothing_ more.)
It's the probe, and a minimal circuit board with a display mounted in a plain plastic tube. Both top and bottom seals are completely airtight. It is convenient to fill the lid with the really small volume storing solution needed for immersing the probe. Then put the lid on, and storing it like that. Strangely enough they feel kinda quality even being this simple. Anyhow I see it as a plus, cause there are fewer components that can break. Also, the plastic is sturdy. I've already dropped mine in the floor a few times. A hit though, or even a scratch directly on the pH-probe/glass"bulb" would surely brake it. But that probably is true with other meter brands. Luckily the probe tip is a little built in, so that it is protected from most objects.

User wise there are only two interactions possible on both meters. On/off, and the potentiometer screw on the back. The potentiometer is turned to adjust the displayed value if necessary after calibration.The screw is not possible to turn by mistake, and not sensitive, making it easy to set to the right value.

For some reason the EC-meter got a slightly bigger display with a back light.

I bought my meters for 10£/meter, which they definitely are worth. When I've googled around though I generally see much higher prices, seems to be a price range as wide as from 10-55€. These should not cost more than ~€20/piece. They're definitely NOT worth that much.
Both meters came preloaded with batteries, in a transparent case with a screwdriver and a manual. The pH-meter also had a pH 7.01 buffer sachet.

So far I really like these. I've noticed a BIG risk thou. There is no extra tightening around the adjustment/potentiometer screw on the back. it's just a whole in the plastic the size of the screw, which around there is no extra tightening. If the meter were immersed in water it would probably leak some into the electronics. I guess even a good splash could make it moist in there. I know I'm gonna get a piece of suitable tape or something to cover it between adjustments to be sure. If I find one small enough of these "dry-bags," shipped with some electronics, it'll definitely be put inside as well, just to be sure.

Apart from this potential risk(Which isn't a risk if you're aware/take precautions). This is really GREAT value for your money, if all you need is a digital meter to take repeated readings now and then. I highly recommend, what other functions are really worth paying for? These kind of pH-probes usually "lasts for 1½-2 years, if you take care of them properly". The EC-probes are almost indestructible though. The pH-probes however should _never_ be allowed to get dry. That can cause future readings becoming more unreliable. They should also be stored in something as similar to what's inside the bulb as possible, aka storing-solution. Buffer-solution is pretty OK, only thing you should really avoid is distilled/RO-water, even if it may "feel" pure/clean. This might not be the whole world, but it _will_ shorten the probe lifespan, but by how much, I have no idea.

Front, back..

Underside, and top-under lid

Might add that storing solution is Potassium chloride (KCl), which at least I can buy REALLY cheaply as "mineral salt"(healthier food-salt). One unit will last a lifetime.

It is also easy to cheaply make your own buffersolution. I use baking soda. You might not get a precise round number, but just note it, and with this meters calibration adjustment method, in form of an analogue adjustment screw, you can use it.

Almost free pH management!

So. Today measuring. Having probe submerged in "normally" temped nutrient solution. Suddenly my values jumped from 6.0pH-ish to 4.0pH. I didn't understand nothing, just thought the probe had freaked out. And it had, in a way... Heres how the glass tip of the probe looks now:


Very sad . Conclusion is this meter has got two cons. If not aware it's easy to get moisture into electronics, and now the fact it being VERY fragile. At least for me it seems very fragile. Didn't hit it or do anything violent. Have dropped it in the floor at an earlier occasion though. But nothing now. Would be interesting to hear if anyone else have had any experience with this, and others, so that he/she can compare them, telling me just how fragile this actually is in comparison.

Since I can buy at least 4-5 of these for the same price as one of another brand, I'm actually gonna buy another of this same "brand", and hope that it was just me being unlucky this time. That is, if no one else has, and gives info telling me I shouldn't. If all are gonna break this easily it ain't worth it. This is also since I got no time learning and choosing among the expensive ones. I need one fast. If there is a next time soon it breaks at least I'll at that time directly know what else I'm gonna buy, cause by then I'll have learned.

Now from my point of view, this thread, and this "review" ends here and now. I will report back though if the next one breaks anytime soon . I really hope I won't be reporting back though, cause this was a really good working meter when it worked, and if not continuing to break, really good value for your money!
Thank you!

Alright. Said it would be last, but since I took the meter apart for myself, I just have to share it as well. At least some must be interested!

Alright. Opening it up, the "white" was some "silicone"/something-tightener I had to scrape off. Anyway, you can first see the "back" with the two electrodes. The glass bulb, and the other in some kind of jelly. You can also see a transistor, and the potentiometer/variable resistor which you use to adjust the value when calibrating from outside.
I can see that the plus from the battery goes directly to one of the transistors legs. Another transistor leg is connected directly to the left/down electrode. You can also guess that the potentiometer is connected to this. Thereby using the transistor to control the current through the electrodes, and the potentiometer to adjust it all.


On the front you can see the "upper" electrode directly connected into the ic, feeding it a small current and letting it know the voltage over the solution between the electrodes. Thereafter the ic "calculates" and lites the appropriate segments of the lcd-display to show this "fluid-value".


Budget meter as said, so not much inside, and what is, simple things. But hey, less things wich can brake, and just need to display the values. Could just wish the glass was a little sturdier.. Maybe that ain't possible?

Hope someone likes this. Thank u!