Hey peeps quick question.

I bought a digital Ph meter yesterday, so anyway got it calibrated it and tested my tap water it was 7.85 not to bad, i then tested the water i had left sitting out for 24Hrs and it was 6.84 i'm in soil so this is fine.

But then i was reading a few things about how the temprature of the water changes the Ph reading is this correct?

If so then how do u know what the Ph is then if the temp of the water affects this?

I dont know if this is fact but i was told that ph meters are calibrated with a 22 degree solution so providing your water temp is around this then no probs

Also dont take ph readings while bubbling cos this can give lower readings

Take air out for at least an hour then test the ph

Owd

Cheers Owd, ye well on the calibration fluid it does tell u what the meter should show at certain temps so that could well be right.

When i calibrated it the fluid temp was at 21.8, then when i tested the water i had left sitting out for 24Hrs the temp was 22.6 and it read 6.84.

Back in a min am going to try with the old method and c if theres any dif in clour from tap water to the stuff that i left sitting out.

Ok tested both the tap water and the water that had been sitting out for 24Hrs with the old way and the tap water was roughly ph 8 and the water that had sat for 24hrs is roughly ph7.

Does this sound about rite that it would drop by 1 over 24hrs?

I then tested with the Digi meter and the tap water was ph7.93 and the temp was 15.4, the water that had sat for 24hrs was ph7.34 and the temp was 19.2. Doesn't really help much

I'm going to re-calibrate it, mark what the temp of the solution is then get a sample of both waters get them at the same temp as the solution then test and c what the ph is of both samples

Ok so i'm having more trouble with this stupid thing.

I put it in the ph6.864 solution it says that if the temp of the solution is between 20-25c then it should read between 6.88-6.86 so i adjusted it to 6.87 as the temp is 21.9c

It then says put it in the ph4.003 solution and it should read 4.00 if the temp is between 20-25, the temp of the solution is 21.8c yet the meter is giving a ph reading of 4.13.

Now it does say that the accuracy has a varation of + or - 0.1 on the ph so do u's think thats it calibrated properly????

Ok i think earlier i calibrated it properly. The solution was at 21.9c for calibration so i took 2 samples of water 1 from the tap n 1 that had been sitting out for just over 24hrs now.

The tap water i warmed up to 21.6c close enough to 21.9c n the ph was 7.53.

The 1 that had been sitting out for 24hrs i also warmed it up to 21.6 n it n its ph was 7.10

So i'm thinkin that Owd is rite in saying that the water temp has to be close to the temp of the solution that was used to calibrate it.