spudfarmerboy
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- Joined
- 23/6/10
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I have a cheap pH meter I bought of Ebay. When I calibrate it, I use Labserv 4 and 9 buffer solutions. Using the 4 buffer solution, the pH meter indicates 4, when using the 9 buffer solution, the pH meter indicates 8.9. Close enough for me.
But when I measure the pH of my tap water at home, the meter will sometimes show 5,4 6, 7. All over the place. It will usually indicate close to the last pH reading that the meter measured.
My tap water is rain water collected off a colourbond roof, onto colourbond guttering, into PVC piping, into a polyethylene ( I think) 40,000 litre water tank.
After trying to measure my tap water pH, if I put the pH probe back into the buffer solutions, it will measure them correctly. So from this, I conclude that the probe works fine. I have not tried measuring other tap water, such as from a reticulated supply.
Are there any science/chemistry people on AHB that may know why this is the case? Is it because it is rain water and doesn't contain many ions or minerals (?) or whatever?
Looking forward to learning what is happening.
Cheers
But when I measure the pH of my tap water at home, the meter will sometimes show 5,4 6, 7. All over the place. It will usually indicate close to the last pH reading that the meter measured.
My tap water is rain water collected off a colourbond roof, onto colourbond guttering, into PVC piping, into a polyethylene ( I think) 40,000 litre water tank.
After trying to measure my tap water pH, if I put the pH probe back into the buffer solutions, it will measure them correctly. So from this, I conclude that the probe works fine. I have not tried measuring other tap water, such as from a reticulated supply.
Are there any science/chemistry people on AHB that may know why this is the case? Is it because it is rain water and doesn't contain many ions or minerals (?) or whatever?
Looking forward to learning what is happening.
Cheers