How hard is it to callibrate pH meters?

GiantEthiopian

GiantEthiopian

New Member
I'm about to purchase my last item on my list, to finally start my grow :hump:

I have never messed around with pH meters, but I've come to the conclusion that you have to "calibrate" them...

How hard is that really? :confused:

I know you have to mix the electrode in a "buffer solution" that makes sure the meter is accurate.

Is it really that hard?

Can a caveman do it? LOL
 
B

bluebottle

Active Member
Extremely easy. Just put your electrode in the buffer and turn a dial until it calibrates. Takes only 20 second max for mine.
 
Al B. Fuct

Al B. Fuct

once had a dog named
Different meters have different means of calibration.

Eutech pH meters require you put the electrode in a known-value cal solution (4.0 or 7.0), press a button to enter cal mode then press one more button to set the calibration.

pH meters' electrodes must be stored damp. A bit of sponge in the meter cap, wet once a week with water and a drop of 50% grade H2O2 will keep the electrode damp and stop fungal growth on the electrodes. Dirty electrodes cause slow reading and calibration. Electrodes will have a very short life if they are not kept moist- they only last about 2 years anyway.

When choosing a meter, a user-replaceable electrode unit is nice, otherwise the unit will have to go off to service for electrode replacement in a couple of years or you will have to replace the entire unit.
 
Al B. Fuct

Al B. Fuct

once had a dog named
good to hear it. :)

While I'm thinking of it, it's a good idea to scrub up the electrode weekly with a toothbrush and an H2O2 in water soln (1ml 50% grade H2O2 in ~10 ml water) to keep it squeaky clean and fixing readings as quickly as it did when new.

4.0 & 7.0 calibration solutions can develop fungal growth if kept at room temp for long periods. It's best to buy a 1-2 litre bottle of each and put about 50-100ml in a small, sealable plastic container for dipping the meter, deep enough to fully immerse the electrode. Keep the bulk solution in the fridge. If you notice cloudy gack forming in the containers used for dipping, discard that solution, wash the container and get more cal soln from the fridge.

Allow the soln to come to room temp before calibrating your meter. Temp is one of the factors the meter is using when calculating pH. If you calibrate to a cold soln the reading might not be right in your room-temp reservoir.
 
Al B. Fuct

Al B. Fuct

once had a dog named
oh, and... :D

I have a Bluelab Truncheon nutrient meter. Fabulous thing, has lasted about 7 years. Bulletproof, can't beat it. The Truncheon's row of blinking LEDs instead of a digital display is an incredibly practical thing for ppl with poor eyesight. Anyone can read it at arm's length.

Bluelab are now trying to sell a Truncheon style pH meter. I wanted to love the pHTruncheon... but I went through 3 of them before I gave up. They would lose calibration and then fail to calibrate. They have a klunky and time consuming calibration method, to boot. Give the pHTruncheon a miss.
 
unholycode

unholycode

Active Member
Al B. Fuct said:
Yes, that will work fine. However, if you don't want to use your cal soln for storage, you can also use distilled water.
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The instructions with it specifically say not to use distilled or deionized water for storage. Mayby cause they want us to buy their storage solution? But I read online of another model from hanna that says you can use the 7.0 solution for storage but this manual doesn't say it. I thought someone might have some experience with it.
 
Al B. Fuct

Al B. Fuct

once had a dog named
unholycode said:
The instructions with it specifically say not to use distilled or deionized water for storage. Mayby cause they want us to buy their storage solution? But I read online of another model from hanna that says you can use the 7.0 solution for storage but this manual doesn't say it. I thought someone might have some experience with it.
Click to expand...
Beats me why they'd disadvise using distilled or DI water for storage! The calibration solutions actually start out with distilled or DI water, then they add some phosphoric or nitric acid to set the pH to 4 or 7, bottle it up & sell it to y'all!

Very odd.
 
VictorVIcious

VictorVIcious

Well-Known Member
They do not want you to use treated water that has a ph lower than 7, It can cause it to drift. You can use tap water, you do not have to store the one I have in the ph solutions. Mine is a Blue Lab Tri-meter, I have seen similar information from other manufactures. VV
 
VictorVIcious

VictorVIcious

Well-Known Member
Its kinda funny, now I have the Tri-Meter. Unless the difference in results are truly amazing I won't now if it really helped me or not. I don't have your stat's to compare, well I have your stat's, I don't have mine.
One side benefit I have found with using a trimeter, it does kinda regulate the day. VV
 
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