pH probe

[RMPD109]

I am trying to ease my parameter testing . I just dont like the color matching charts. Anyhow, I purchased a pH meter(pen style). My new probe is way off from my liquid tests. I want to recalibrate and have a small amount of solutions(7.0&4.0). Do I mix a solution from these tiny bottles? -OR- Do I drop a couple drops on the probe?

I purchased this on ebay. Company technika, model PHPRO

Any help is appreciated as always

 

[TankGirl]

You need to place the probe into the solution, completely submerged. Do not mix the solutions. The biggest thing with these pens is that the tip be wet, so you need to soak it in deionized (distilled) water for a few minutes before you test. Then you need to leave the probe in your sample of tank water, or in the tank, like I do ( ) for a few minutes for it to stabilize. I have found it to be "off" when I first put it in, but if it is correctly calibrated then you can trust the results.

 

[RMPD109]

I am still not sure about the calibration solution. I know not to mix the two together but can I dilute them or something to make more of it. The tester I have came with a dropper of each solution. Definately not enough to submerge the probe to the immersion line. I will try the distilled water and then testing the tank. Does distilled water have a standard pH like it does salinety (0) etc?

Thanks for the advice TG

 

[TankGirl]

I am not familiar with using a dropper - you can't dilute the calibration solutions or your results will not be accurate. I am familiar with small pouches or "sachets" of solution, that are about 2.5" square, and contain enough solution to immerse your probe into. Or, you can get solution in bottles and you pour it into a small cup, You need about a medicine-cup's worth of solution for the probe I have.

If you go to the Technika website they sell bottles of solution, and if no one comes along here who has this model maybe they can help you at Technika pertaining to your particular model.

Distilled water should be pH 7.

 

[cmor1701d]

Distilled water in an open container is at about 5.8pH or less. 5.0 - 6.0 range, so it's not a good solution to calibrate a meter. I would suggest you buy some calibration fluid, both 7.0 and 10.0.

You might want to check with your dealer to find out if you have a concentrated solution that needs to be mixed.

 

[TankGirl]

I did not mean to use it to calibrate, just to rinse off the probe. I am misinformed about the pH of distilled water!

 

[cmor1701d]

I think that distilled water starts at 7.0pH but starts dropping as soon as the CO2 from the surround air hits it.

 

[RMPD109]

This is a generic post of my meter. As you can see it is not a single protruding probe. Almost the entire lower section must be submerged. Do you think I can just pt a few drops of solution on the probe inside the housing and not submerge the unit?

 

[cmor1701d]

I don't think so. The probe needs to be submerged in fluid to get an accurate reading. Email the seller and ask about the probe and the solutions. I would just order some 7.0 and 10.0 solution online

 

[RMPD109]

Sounds good I will order some right now- thanks

Just because my readings are so far off from my liquid tests is there anything with a constant pH for a quick check(vinager or baking soda water)? I am concerned it is too low. Liquid test shows 8.2 and meter says 7.2.

Should I add the 8.3 buffer just in case. That would bring it up to the target area of 8.3 right?

 

[TankGirl]

Your solutions are the best "constant pH" liquid, if you can get enough of it to test.

I'd compare it to a liquid reagent test and see what you get, and not trust the results until you get your calibration solutions - the probe is really useless without calibration, so you might as well not use it or not trust the results until it can be calibrated.

 

[cmor1701d]

If you haven't been there already here's the website for your meter:
http://www.technika.com/Sper/s840037.htm

 

[RMPD109]

I have been to the site and emailed them about it. It took two days to respond and all they said was they know I shouldnt mix the solutions together(duh). Not much help but it was the sales division that emailed me not a technician.

 

[RMPD109]

well I took a sample to the LFS tonight. They tested for pH and it was close to the meter reading and not my liquid test. I am going to add buffer now and bring it up just a tad. Thanks to all who helped